After talking to Bruce Evans and reading more standards specs,
switch to using C99-style comments everywhere in preprocessed assembler. The reason is that lines starting with the regexp '^[[:space:]]#' are treated as preprocessing directives, and while it seems to work now with GCC, it's not necessarily has to work. Use C99 comments `//' for the trailing comments to save whitespace.
This commit is contained in:
Ruslan Ermilov
parent
fe2c61013d
commit
edfa817773
@ -16,33 +16,33 @@
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*/
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/* Memory Locations */
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.set MEM_REL,0x700 # Relocation address
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.set MEM_ARG,0x900 # Arguments
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.set MEM_ORG,0x7c00 # Origin
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.set MEM_BUF,0x8cec # Load area
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.set MEM_BTX,0x9000 # BTX start
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.set MEM_JMP,0x9010 # BTX entry point
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.set MEM_USR,0xa000 # Client start
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.set BDA_BOOT,0x472 # Boot howto flag
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.set MEM_REL,0x700 // Relocation address
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.set MEM_ARG,0x900 // Arguments
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.set MEM_ORG,0x7c00 // Origin
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.set MEM_BUF,0x8cec // Load area
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.set MEM_BTX,0x9000 // BTX start
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.set MEM_JMP,0x9010 // BTX entry point
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.set MEM_USR,0xa000 // Client start
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.set BDA_BOOT,0x472 // Boot howto flag
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/* Partition Constants */
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.set PRT_OFF,0x1be # Partition offset
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.set PRT_NUM,0x4 # Partitions
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.set PRT_BSD,0xa5 # Partition type
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.set PRT_OFF,0x1be // Partition offset
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.set PRT_NUM,0x4 // Partitions
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.set PRT_BSD,0xa5 // Partition type
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/* Flag Bits */
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.set FL_PACKET,0x80 # Packet mode
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.set FL_PACKET,0x80 // Packet mode
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/* Misc. Constants */
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.set SIZ_PAG,0x1000 # Page size
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.set SIZ_SEC,0x200 # Sector size
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.set SIZ_PAG,0x1000 // Page size
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.set SIZ_SEC,0x200 // Sector size
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.set NSECT,0x10
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.globl start
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.globl xread
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.code16
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start: jmp main # Start recognizably
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start: jmp main // Start recognizably
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/*
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* This is the start of a standard BIOS Parameter Block (BPB). Most bootable
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@ -59,24 +59,24 @@ start: jmp main # Start recognizably
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* move the "prompt" message data (below) to replace the OEM ID.
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*/
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.org 0x03, 0x00
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oemid: .space 0x08, 0x00 # OEM ID
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oemid: .space 0x08, 0x00 // OEM ID
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.org 0x0b, 0x00
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bpb: .word 512 # sector size (T)
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.byte 0 # sectors/clustor
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.word 0 # reserved sectors
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.byte 0 # number of FATs
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.word 0 # root entries
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.word 0 # small sectors
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.byte 0 # media type (W)
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.word 0 # sectors/fat
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.word 18 # sectors per track (T)
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.word 2 # number of heads (T)
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.long 0 # hidden sectors (W)
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.long 0 # large sectors
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bpb: .word 512 // sector size (T)
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.byte 0 // sectors/clustor
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.word 0 // reserved sectors
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.byte 0 // number of FATs
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.word 0 // root entries
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.word 0 // small sectors
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.byte 0 // media type (W)
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.word 0 // sectors/fat
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.word 18 // sectors per track (T)
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.word 2 // number of heads (T)
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.long 0 // hidden sectors (W)
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.long 0 // large sectors
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.org 0x24, 0x00
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ebpb: .byte 0 # BIOS physical drive number (W)
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ebpb: .byte 0 // BIOS physical drive number (W)
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.org 0x25,0x90
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/*
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@ -89,25 +89,25 @@ ebpb: .byte 0 # BIOS physical drive number (W)
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* %dh - byte - num sectors to read
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*/
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xread: push %ss # Address
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pop %ds # data
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xread: push %ss // Address
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pop %ds // data
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/*
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* Setup an EDD disk packet and pass it to read
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*/
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xread.1: # Starting
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pushl $0x0 # absolute
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push %cx # block
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push %ax # number
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push %es # Address of
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push %bx # transfer buffer
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xor %ax,%ax # Number of
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movb %dh,%al # blocks to
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push %ax # transfer
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push $0x10 # Size of packet
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mov %sp,%bp # Packet pointer
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callw read # Read from disk
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lea 0x10(%bp),%sp # Clear stack
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lret # To far caller
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xread.1: // Starting
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pushl $0x0 // absolute
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push %cx // block
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push %ax // number
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push %es // Address of
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push %bx // transfer buffer
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xor %ax,%ax // Number of
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movb %dh,%al // blocks to
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push %ax // transfer
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push $0x10 // Size of packet
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mov %sp,%bp // Packet pointer
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callw read // Read from disk
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lea 0x10(%bp),%sp // Clear stack
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lret // To far caller
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/*
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* Load the rest of boot2 and BTX up, copy the parts to the right locations,
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* and start it all up.
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@ -117,21 +117,21 @@ xread.1: # Starting
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* Setup the segment registers to flat addressing (segment 0) and setup the
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* stack to end just below the start of our code.
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*/
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main: cld # String ops inc
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xor %cx,%cx # Zero
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mov %cx,%es # Address
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mov %cx,%ds # data
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mov %cx,%ss # Set up
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mov $start,%sp # stack
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main: cld // String ops inc
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xor %cx,%cx // Zero
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mov %cx,%es // Address
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mov %cx,%ds // data
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mov %cx,%ss // Set up
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mov $start,%sp // stack
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/*
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* Relocate ourself to MEM_REL. Since %cx == 0, the inc %ch sets
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* %cx == 0x100.
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*/
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mov %sp,%si # Source
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mov $MEM_REL,%di # Destination
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incb %ch # Word count
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rep # Copy
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movsw # code
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mov %sp,%si // Source
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mov $MEM_REL,%di // Destination
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incb %ch // Word count
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rep // Copy
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movsw // code
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/*
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* If we are on a hard drive, then load the MBR and look for the first
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* FreeBSD slice. We use the fake partition entry below that points to
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@ -139,35 +139,35 @@ main: cld # String ops inc
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* FreeBSD slice. The second pass looks for the first non-active FreeBSD
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* slice if the first one fails.
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*/
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mov $part4,%si # Partition
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cmpb $0x80,%dl # Hard drive?
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jb main.4 # No
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movb $0x1,%dh # Block count
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callw nread # Read MBR
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mov $0x1,%cx # Two passes
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main.1: mov $MEM_BUF+PRT_OFF,%si # Partition table
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movb $0x1,%dh # Partition
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main.2: cmpb $PRT_BSD,0x4(%si) # Our partition type?
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jne main.3 # No
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jcxz main.5 # If second pass
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testb $0x80,(%si) # Active?
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jnz main.5 # Yes
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main.3: add $0x10,%si # Next entry
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incb %dh # Partition
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cmpb $0x1+PRT_NUM,%dh # In table?
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jb main.2 # Yes
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dec %cx # Do two
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jcxz main.1 # passes
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mov $part4,%si // Partition
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cmpb $0x80,%dl // Hard drive?
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jb main.4 // No
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movb $0x1,%dh // Block count
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callw nread // Read MBR
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mov $0x1,%cx // Two passes
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main.1: mov $MEM_BUF+PRT_OFF,%si // Partition table
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movb $0x1,%dh // Partition
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main.2: cmpb $PRT_BSD,0x4(%si) // Our partition type?
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jne main.3 // No
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jcxz main.5 // If second pass
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testb $0x80,(%si) // Active?
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jnz main.5 // Yes
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main.3: add $0x10,%si // Next entry
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incb %dh // Partition
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cmpb $0x1+PRT_NUM,%dh // In table?
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jb main.2 // Yes
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dec %cx // Do two
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jcxz main.1 // passes
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/*
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* If we get here, we didn't find any FreeBSD slices at all, so print an
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* error message and die.
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*/
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mov $msg_part,%si # Message
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jmp error # Error
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mov $msg_part,%si // Message
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jmp error // Error
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/*
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* Floppies use partition 0 of drive 0.
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*/
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main.4: xor %dx,%dx # Partition:drive
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main.4: xor %dx,%dx // Partition:drive
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/*
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* Ok, we have a slice and drive in %dx now, so use that to locate and load
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* boot2. %si references the start of the slice we are looking for, so go
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@ -182,80 +182,80 @@ main.4: xor %dx,%dx # Partition:drive
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* when we use btxld to create boot2, we use an entry point of 0x2000. That
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* entry point is relative to MEM_USR; thus boot2.bin starts at 0xc000.
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*/
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main.5: mov %dx,MEM_ARG # Save args
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movb $NSECT,%dh # Sector count
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callw nread # Read disk
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mov $MEM_BTX,%bx # BTX
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mov 0xa(%bx),%si # Get BTX length and set
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add %bx,%si # %si to start of boot2.bin
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mov $MEM_USR+SIZ_PAG*2,%di # Client page 2
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mov $MEM_BTX+(NSECT-1)*SIZ_SEC,%cx # Byte
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sub %si,%cx # count
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rep # Relocate
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movsb # client
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sub %di,%cx # Byte count
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xorb %al,%al # Zero assumed bss from
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rep # the end of boot2.bin
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stosb # up to 0x10000
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callw seta20 # Enable A20
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jmp start+MEM_JMP-MEM_ORG # Start BTX
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main.5: mov %dx,MEM_ARG // Save args
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movb $NSECT,%dh // Sector count
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callw nread // Read disk
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mov $MEM_BTX,%bx // BTX
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mov 0xa(%bx),%si // Get BTX length and set
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add %bx,%si // %si to start of boot2.bin
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mov $MEM_USR+SIZ_PAG*2,%di // Client page 2
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mov $MEM_BTX+(NSECT-1)*SIZ_SEC,%cx // Byte
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sub %si,%cx // count
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rep // Relocate
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movsb // client
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sub %di,%cx // Byte count
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xorb %al,%al // Zero assumed bss from
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rep // the end of boot2.bin
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stosb // up to 0x10000
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callw seta20 // Enable A20
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jmp start+MEM_JMP-MEM_ORG // Start BTX
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/*
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* Enable A20 so we can access memory above 1 meg.
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*/
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seta20: cli # Disable interrupts
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seta20.1: inb $0x64,%al # Get status
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testb $0x2,%al # Busy?
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jnz seta20.1 # Yes
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movb $0xd1,%al # Command: Write
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outb %al,$0x64 # output port
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seta20.2: inb $0x64,%al # Get status
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testb $0x2,%al # Busy?
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jnz seta20.2 # Yes
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movb $0xdf,%al # Enable
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outb %al,$0x60 # A20
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sti # Enable interrupts
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retw # To caller
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seta20: cli // Disable interrupts
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seta20.1: inb $0x64,%al // Get status
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testb $0x2,%al // Busy?
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jnz seta20.1 // Yes
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movb $0xd1,%al // Command: Write
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outb %al,$0x64 // output port
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seta20.2: inb $0x64,%al // Get status
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testb $0x2,%al // Busy?
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jnz seta20.2 // Yes
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movb $0xdf,%al // Enable
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outb %al,$0x60 // A20
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sti // Enable interrupts
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retw // To caller
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/*
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* Trampoline used to call read from within boot1.
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*/
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nread: mov $MEM_BUF,%bx # Transfer buffer
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mov 0x8(%si),%ax # Get
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mov 0xa(%si),%cx # LBA
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push %cs # Read from
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callw xread.1 # disk
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jnc return # If success, return
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mov $msg_read,%si # Otherwise, set the error
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# message and fall through to
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# the error routine
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nread: mov $MEM_BUF,%bx // Transfer buffer
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mov 0x8(%si),%ax // Get
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mov 0xa(%si),%cx // LBA
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push %cs // Read from
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callw xread.1 // disk
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jnc return // If success, return
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mov $msg_read,%si // Otherwise, set the error
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// message and fall through to
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// the error routine
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/*
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* Print out the error message pointed to by %ds:(%si) followed
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* by a prompt, wait for a keypress, and then reboot the machine.
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*/
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error: callw putstr # Display message
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mov $prompt,%si # Display
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callw putstr # prompt
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xorb %ah,%ah # BIOS: Get
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int $0x16 # keypress
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movw $0x1234, BDA_BOOT # Do a warm boot
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ljmp $0xffff,$0x0 # reboot the machine
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error: callw putstr // Display message
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mov $prompt,%si // Display
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callw putstr // prompt
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xorb %ah,%ah // BIOS: Get
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int $0x16 // keypress
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movw $0x1234, BDA_BOOT // Do a warm boot
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ljmp $0xffff,$0x0 // reboot the machine
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/*
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* Display a null-terminated string using the BIOS output.
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*/
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putstr.0: mov $0x7,%bx # Page:attribute
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movb $0xe,%ah # BIOS: Display
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int $0x10 # character
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putstr: lodsb # Get char
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testb %al,%al # End of string?
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jne putstr.0 # No
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putstr.0: mov $0x7,%bx // Page:attribute
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movb $0xe,%ah // BIOS: Display
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int $0x10 // character
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putstr: lodsb // Get char
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testb %al,%al // End of string?
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jne putstr.0 // No
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/*
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* Overused return code. ereturn is used to return an error from the
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* read function. Since we assume putstr succeeds, we (ab)use the
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* same code when we return from putstr.
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*/
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ereturn: movb $0x1,%ah # Invalid
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stc # argument
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return: retw # To caller
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ereturn: movb $0x1,%ah // Invalid
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stc // argument
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return: retw // To caller
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/*
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* Reads sectors from the disk. If EDD is enabled, then check if it is
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* installed and use it if it is. If it is not installed or not enabled, then
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@ -266,83 +266,83 @@ return: retw # To caller
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* %dl - byte - drive number
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* stack - 10 bytes - EDD Packet
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*/
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read: push %dx # Save
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movb $0x8,%ah # BIOS: Get drive
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int $0x13 # parameters
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movb %dh,%ch # Max head number
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pop %dx # Restore
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jc return # If error
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andb $0x3f,%cl # Sectors per track
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jz ereturn # If zero
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cli # Disable interrupts
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mov 0x8(%bp),%eax # Get LBA
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push %dx # Save
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movzbl %cl,%ebx # Divide by
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xor %edx,%edx # sectors
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div %ebx # per track
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movb %ch,%bl # Max head number
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movb %dl,%ch # Sector number
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inc %bx # Divide by
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xorb %dl,%dl # number
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div %ebx # of heads
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movb %dl,%bh # Head number
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pop %dx # Restore
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cmpl $0x3ff,%eax # Cylinder number supportable?
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sti # Enable interrupts
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ja read.7 # No, try EDD
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xchgb %al,%ah # Set up cylinder
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rorb $0x2,%al # number
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orb %ch,%al # Merge
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inc %ax # sector
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xchg %ax,%cx # number
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movb %bh,%dh # Head number
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subb %ah,%al # Sectors this track
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mov 0x2(%bp),%ah # Blocks to read
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cmpb %ah,%al # To read
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jb read.2 # this
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||||
read: push %dx // Save
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||||
movb $0x8,%ah // BIOS: Get drive
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int $0x13 // parameters
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||||
movb %dh,%ch // Max head number
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pop %dx // Restore
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jc return // If error
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||||
andb $0x3f,%cl // Sectors per track
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||||
jz ereturn // If zero
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||||
cli // Disable interrupts
|
||||
mov 0x8(%bp),%eax // Get LBA
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push %dx // Save
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||||
movzbl %cl,%ebx // Divide by
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||||
xor %edx,%edx // sectors
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||||
div %ebx // per track
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||||
movb %ch,%bl // Max head number
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||||
movb %dl,%ch // Sector number
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||||
inc %bx // Divide by
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xorb %dl,%dl // number
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||||
div %ebx // of heads
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||||
movb %dl,%bh // Head number
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||||
pop %dx // Restore
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||||
cmpl $0x3ff,%eax // Cylinder number supportable?
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||||
sti // Enable interrupts
|
||||
ja read.7 // No, try EDD
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||||
xchgb %al,%ah // Set up cylinder
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||||
rorb $0x2,%al // number
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||||
orb %ch,%al // Merge
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||||
inc %ax // sector
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||||
xchg %ax,%cx // number
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||||
movb %bh,%dh // Head number
|
||||
subb %ah,%al // Sectors this track
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||||
mov 0x2(%bp),%ah // Blocks to read
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||||
cmpb %ah,%al // To read
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||||
jb read.2 // this
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||||
#ifdef TRACK_AT_A_TIME
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||||
movb %ah,%al # track
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||||
movb %ah,%al // track
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||||
#else
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||||
movb $1,%al # one sector
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||||
movb $1,%al // one sector
|
||||
#endif
|
||||
read.2: mov $0x5,%di # Try count
|
||||
read.3: les 0x4(%bp),%bx # Transfer buffer
|
||||
push %ax # Save
|
||||
movb $0x2,%ah # BIOS: Read
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||||
int $0x13 # from disk
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||||
pop %bx # Restore
|
||||
jnc read.4 # If success
|
||||
dec %di # Retry?
|
||||
jz read.6 # No
|
||||
xorb %ah,%ah # BIOS: Reset
|
||||
int $0x13 # disk system
|
||||
xchg %bx,%ax # Block count
|
||||
jmp read.3 # Continue
|
||||
read.4: movzbw %bl,%ax # Sectors read
|
||||
add %ax,0x8(%bp) # Adjust
|
||||
jnc read.5 # LBA,
|
||||
incw 0xa(%bp) # transfer
|
||||
read.5: shlb %bl # buffer
|
||||
add %bl,0x5(%bp) # pointer,
|
||||
sub %al,0x2(%bp) # block count
|
||||
ja read # If not done
|
||||
read.6: retw # To caller
|
||||
read.7: testb $FL_PACKET,%cs:MEM_REL+flags-start # LBA support enabled?
|
||||
jz ereturn # No, so return an error
|
||||
mov $0x55aa,%bx # Magic
|
||||
push %dx # Save
|
||||
movb $0x41,%ah # BIOS: Check
|
||||
int $0x13 # extensions present
|
||||
pop %dx # Restore
|
||||
jc return # If error, return an error
|
||||
cmp $0xaa55,%bx # Magic?
|
||||
jne ereturn # No, so return an error
|
||||
testb $0x1,%cl # Packet interface?
|
||||
jz ereturn # No, so return an error
|
||||
mov %bp,%si # Disk packet
|
||||
movb $0x42,%ah # BIOS: Extended
|
||||
int $0x13 # read
|
||||
retw # To caller
|
||||
read.2: mov $0x5,%di // Try count
|
||||
read.3: les 0x4(%bp),%bx // Transfer buffer
|
||||
push %ax // Save
|
||||
movb $0x2,%ah // BIOS: Read
|
||||
int $0x13 // from disk
|
||||
pop %bx // Restore
|
||||
jnc read.4 // If success
|
||||
dec %di // Retry?
|
||||
jz read.6 // No
|
||||
xorb %ah,%ah // BIOS: Reset
|
||||
int $0x13 // disk system
|
||||
xchg %bx,%ax // Block count
|
||||
jmp read.3 // Continue
|
||||
read.4: movzbw %bl,%ax // Sectors read
|
||||
add %ax,0x8(%bp) // Adjust
|
||||
jnc read.5 // LBA,
|
||||
incw 0xa(%bp) // transfer
|
||||
read.5: shlb %bl // buffer
|
||||
add %bl,0x5(%bp) // pointer,
|
||||
sub %al,0x2(%bp) // block count
|
||||
ja read // If not done
|
||||
read.6: retw // To caller
|
||||
read.7: testb $FL_PACKET,%cs:MEM_REL+flags-start // LBA support enabled?
|
||||
jz ereturn // No, so return an error
|
||||
mov $0x55aa,%bx // Magic
|
||||
push %dx // Save
|
||||
movb $0x41,%ah // BIOS: Check
|
||||
int $0x13 // extensions present
|
||||
pop %dx // Restore
|
||||
jc return // If error, return an error
|
||||
cmp $0xaa55,%bx // Magic?
|
||||
jne ereturn // No, so return an error
|
||||
testb $0x1,%cl // Packet interface?
|
||||
jz ereturn // No, so return an error
|
||||
mov %bp,%si // Disk packet
|
||||
movb $0x42,%ah // BIOS: Extended
|
||||
int $0x13 // read
|
||||
retw // To caller
|
||||
|
||||
/* Messages */
|
||||
|
||||
@ -351,7 +351,7 @@ msg_part: .asciz "Boot"
|
||||
|
||||
prompt: .asciz " error\r\n"
|
||||
|
||||
flags: .byte FLAGS # Flags
|
||||
flags: .byte FLAGS // Flags
|
||||
|
||||
.org PRT_OFF,0x90
|
||||
|
||||
@ -361,6 +361,6 @@ flags: .byte FLAGS # Flags
|
||||
part4: .byte 0x80, 0x00, 0x01, 0x00
|
||||
.byte 0xa5, 0xfe, 0xff, 0xff
|
||||
.byte 0x00, 0x00, 0x00, 0x00
|
||||
.byte 0x50, 0xc3, 0x00, 0x00 # 50000 sectors long, bleh
|
||||
.byte 0x50, 0xc3, 0x00, 0x00 // 50000 sectors long, bleh
|
||||
|
||||
.word 0xaa55 # Magic number
|
||||
.word 0xaa55 // Magic number
|
||||
|
||||
@ -15,9 +15,9 @@
|
||||
* $FreeBSD$
|
||||
*/
|
||||
|
||||
.set SIO_PRT,SIOPRT # Base port
|
||||
.set SIO_FMT,SIOFMT # 8N1
|
||||
.set SIO_DIV,(115200/SIOSPD) # 115200 / SPD
|
||||
.set SIO_PRT,SIOPRT // Base port
|
||||
.set SIO_FMT,SIOFMT // 8N1
|
||||
.set SIO_DIV,(115200/SIOSPD) // 115200 / SPD
|
||||
|
||||
.globl sio_init
|
||||
.globl sio_flush
|
||||
@ -27,54 +27,54 @@
|
||||
|
||||
/* void sio_init(void) */
|
||||
|
||||
sio_init: movw $SIO_PRT+0x3,%dx # Data format reg
|
||||
movb $SIO_FMT|0x80,%al # Set format
|
||||
outb %al,(%dx) # and DLAB
|
||||
pushl %edx # Save
|
||||
subb $0x3,%dl # Divisor latch reg
|
||||
movw $SIO_DIV,%ax # Set
|
||||
outw %ax,(%dx) # BPS
|
||||
popl %edx # Restore
|
||||
movb $SIO_FMT,%al # Clear
|
||||
outb %al,(%dx) # DLAB
|
||||
incl %edx # Modem control reg
|
||||
movb $0x3,%al # Set RTS,
|
||||
outb %al,(%dx) # DTR
|
||||
incl %edx # Line status reg
|
||||
sio_init: movw $SIO_PRT+0x3,%dx // Data format reg
|
||||
movb $SIO_FMT|0x80,%al // Set format
|
||||
outb %al,(%dx) // and DLAB
|
||||
pushl %edx // Save
|
||||
subb $0x3,%dl // Divisor latch reg
|
||||
movw $SIO_DIV,%ax // Set
|
||||
outw %ax,(%dx) // BPS
|
||||
popl %edx // Restore
|
||||
movb $SIO_FMT,%al // Clear
|
||||
outb %al,(%dx) // DLAB
|
||||
incl %edx // Modem control reg
|
||||
movb $0x3,%al // Set RTS,
|
||||
outb %al,(%dx) // DTR
|
||||
incl %edx // Line status reg
|
||||
|
||||
/* void sio_flush(void) */
|
||||
|
||||
sio_flush.0: call sio_getc.1 # Get character
|
||||
sio_flush: call sio_ischar # Check for character
|
||||
jnz sio_flush.0 # Till none
|
||||
ret # To caller
|
||||
sio_flush.0: call sio_getc.1 // Get character
|
||||
sio_flush: call sio_ischar // Check for character
|
||||
jnz sio_flush.0 // Till none
|
||||
ret // To caller
|
||||
|
||||
/* void sio_putc(int c) */
|
||||
|
||||
sio_putc: movw $SIO_PRT+0x5,%dx # Line status reg
|
||||
xor %ecx,%ecx # Timeout
|
||||
movb $0x40,%ch # counter
|
||||
sio_putc.1: inb (%dx),%al # Transmitter
|
||||
testb $0x20,%al # buffer empty?
|
||||
loopz sio_putc.1 # No
|
||||
jz sio_putc.2 # If timeout
|
||||
movb 0x4(%esp,1),%al # Get character
|
||||
subb $0x5,%dl # Transmitter hold reg
|
||||
outb %al,(%dx) # Write character
|
||||
sio_putc.2: ret $0x4 # To caller
|
||||
sio_putc: movw $SIO_PRT+0x5,%dx // Line status reg
|
||||
xor %ecx,%ecx // Timeout
|
||||
movb $0x40,%ch // counter
|
||||
sio_putc.1: inb (%dx),%al // Transmitter
|
||||
testb $0x20,%al // buffer empty?
|
||||
loopz sio_putc.1 // No
|
||||
jz sio_putc.2 // If timeout
|
||||
movb 0x4(%esp,1),%al // Get character
|
||||
subb $0x5,%dl // Transmitter hold reg
|
||||
outb %al,(%dx) // Write character
|
||||
sio_putc.2: ret $0x4 // To caller
|
||||
|
||||
/* int sio_getc(void) */
|
||||
|
||||
sio_getc: call sio_ischar # Character available?
|
||||
jz sio_getc # No
|
||||
sio_getc.1: subb $0x5,%dl # Receiver buffer reg
|
||||
inb (%dx),%al # Read character
|
||||
ret # To caller
|
||||
sio_getc: call sio_ischar // Character available?
|
||||
jz sio_getc // No
|
||||
sio_getc.1: subb $0x5,%dl // Receiver buffer reg
|
||||
inb (%dx),%al // Read character
|
||||
ret // To caller
|
||||
|
||||
/* int sio_ischar(void) */
|
||||
|
||||
sio_ischar: movw $SIO_PRT+0x5,%dx # Line status register
|
||||
xorl %eax,%eax # Zero
|
||||
inb (%dx),%al # Received data
|
||||
andb $0x1,%al # ready?
|
||||
ret # To caller
|
||||
sio_ischar: movw $SIO_PRT+0x5,%dx // Line status register
|
||||
xorl %eax,%eax // Zero
|
||||
inb (%dx),%al // Received data
|
||||
andb $0x1,%al // ready?
|
||||
ret // To caller
|
||||
|
||||
File diff suppressed because it is too large
Load Diff
@ -23,39 +23,39 @@
|
||||
/*
|
||||
* Memory locations.
|
||||
*/
|
||||
.set MEM_STUB,0x600 # Real mode stub
|
||||
.set MEM_ESP,0x1000 # New stack pointer
|
||||
.set MEM_TBL,0x5000 # BTX page tables
|
||||
.set MEM_ENTRY,0x9010 # BTX entry point
|
||||
.set MEM_DATA,start+0x1000 # Data segment
|
||||
.set MEM_STUB,0x600 // Real mode stub
|
||||
.set MEM_ESP,0x1000 // New stack pointer
|
||||
.set MEM_TBL,0x5000 // BTX page tables
|
||||
.set MEM_ENTRY,0x9010 // BTX entry point
|
||||
.set MEM_DATA,start+0x1000 // Data segment
|
||||
/*
|
||||
* Segment selectors.
|
||||
*/
|
||||
.set SEL_SCODE,0x8 # 4GB code
|
||||
.set SEL_SDATA,0x10 # 4GB data
|
||||
.set SEL_RCODE,0x18 # 64K code
|
||||
.set SEL_RDATA,0x20 # 64K data
|
||||
.set SEL_SCODE,0x8 // 4GB code
|
||||
.set SEL_SDATA,0x10 // 4GB data
|
||||
.set SEL_RCODE,0x18 // 64K code
|
||||
.set SEL_RDATA,0x20 // 64K data
|
||||
/*
|
||||
* Paging constants.
|
||||
*/
|
||||
.set PAG_SIZ,0x1000 # Page size
|
||||
.set PAG_ENT,0x4 # Page entry size
|
||||
.set PAG_SIZ,0x1000 // Page size
|
||||
.set PAG_ENT,0x4 // Page entry size
|
||||
/*
|
||||
* Screen constants.
|
||||
*/
|
||||
.set SCR_MAT,0x7 # Mode/attribute
|
||||
.set SCR_COL,0x50 # Columns per row
|
||||
.set SCR_ROW,0x19 # Rows per screen
|
||||
.set SCR_MAT,0x7 // Mode/attribute
|
||||
.set SCR_COL,0x50 // Columns per row
|
||||
.set SCR_ROW,0x19 // Rows per screen
|
||||
/*
|
||||
* BIOS Data Area locations.
|
||||
*/
|
||||
.set BDA_MEM,0x413 # Free memory
|
||||
.set BDA_SCR,0x449 # Video mode
|
||||
.set BDA_POS,0x450 # Cursor position
|
||||
.set BDA_MEM,0x413 // Free memory
|
||||
.set BDA_SCR,0x449 // Video mode
|
||||
.set BDA_POS,0x450 // Cursor position
|
||||
/*
|
||||
* Required by aout gas inadequacy.
|
||||
*/
|
||||
.set SIZ_STUB,0x1a # Size of stub
|
||||
.set SIZ_STUB,0x1a // Size of stub
|
||||
/*
|
||||
* We expect to be loaded by boot2 at the origin defined in ./Makefile.
|
||||
*/
|
||||
@ -63,303 +63,303 @@
|
||||
/*
|
||||
* BTX program loader for ELF clients.
|
||||
*/
|
||||
start: cld # String ops inc
|
||||
movl $m_logo,%esi # Identify
|
||||
call putstr # ourselves
|
||||
movzwl BDA_MEM,%eax # Get base memory
|
||||
shll $0xa,%eax # in bytes
|
||||
movl %eax,%ebp # Base of user stack
|
||||
start: cld // String ops inc
|
||||
movl $m_logo,%esi // Identify
|
||||
call putstr // ourselves
|
||||
movzwl BDA_MEM,%eax // Get base memory
|
||||
shll $0xa,%eax // in bytes
|
||||
movl %eax,%ebp // Base of user stack
|
||||
#ifdef BTXLDR_VERBOSE
|
||||
movl $m_mem,%esi # Display
|
||||
call hexout # amount of
|
||||
call putstr # base memory
|
||||
movl $m_mem,%esi // Display
|
||||
call hexout // amount of
|
||||
call putstr // base memory
|
||||
#endif
|
||||
lgdt gdtdesc # Load new GDT
|
||||
lgdt gdtdesc // Load new GDT
|
||||
/*
|
||||
* Relocate caller's arguments.
|
||||
*/
|
||||
#ifdef BTXLDR_VERBOSE
|
||||
movl $m_esp,%esi # Display
|
||||
movl %esp,%eax # caller
|
||||
call hexout # stack
|
||||
call putstr # pointer
|
||||
movl $m_args,%esi # Format string
|
||||
leal 0x4(%esp,1),%ebx # First argument
|
||||
movl $0x6,%ecx # Count
|
||||
start.1: movl (%ebx),%eax # Get argument and
|
||||
addl $0x4,%ebx # bump pointer
|
||||
call hexout # Display it
|
||||
loop start.1 # Till done
|
||||
call putstr # End message
|
||||
movl $m_esp,%esi // Display
|
||||
movl %esp,%eax // caller
|
||||
call hexout // stack
|
||||
call putstr // pointer
|
||||
movl $m_args,%esi // Format string
|
||||
leal 0x4(%esp,1),%ebx // First argument
|
||||
movl $0x6,%ecx // Count
|
||||
start.1: movl (%ebx),%eax // Get argument and
|
||||
addl $0x4,%ebx // bump pointer
|
||||
call hexout // Display it
|
||||
loop start.1 // Till done
|
||||
call putstr // End message
|
||||
#endif
|
||||
movl $0x48,%ecx # Allocate space
|
||||
subl %ecx,%ebp # for bootinfo
|
||||
movl 0x18(%esp,1),%esi # Source: bootinfo
|
||||
cmpl $0x0, %esi # If the bootinfo pointer
|
||||
je start_null_bi # is null, don't copy it
|
||||
movl %ebp,%edi # Destination
|
||||
rep # Copy
|
||||
movsb # it
|
||||
movl %ebp,0x18(%esp,1) # Update pointer
|
||||
movl $0x48,%ecx // Allocate space
|
||||
subl %ecx,%ebp // for bootinfo
|
||||
movl 0x18(%esp,1),%esi // Source: bootinfo
|
||||
cmpl $0x0, %esi // If the bootinfo pointer
|
||||
je start_null_bi // is null, don't copy it
|
||||
movl %ebp,%edi // Destination
|
||||
rep // Copy
|
||||
movsb // it
|
||||
movl %ebp,0x18(%esp,1) // Update pointer
|
||||
#ifdef BTXLDR_VERBOSE
|
||||
movl $m_rel_bi,%esi # Display
|
||||
movl %ebp,%eax # bootinfo
|
||||
call hexout # relocation
|
||||
call putstr # message
|
||||
movl $m_rel_bi,%esi // Display
|
||||
movl %ebp,%eax // bootinfo
|
||||
call hexout // relocation
|
||||
call putstr // message
|
||||
#endif
|
||||
start_null_bi: movl $0x18,%ecx # Allocate space
|
||||
subl %ecx,%ebp # for arguments
|
||||
leal 0x4(%esp,1),%esi # Source
|
||||
movl %ebp,%edi # Destination
|
||||
rep # Copy
|
||||
movsb # them
|
||||
start_null_bi: movl $0x18,%ecx // Allocate space
|
||||
subl %ecx,%ebp // for arguments
|
||||
leal 0x4(%esp,1),%esi // Source
|
||||
movl %ebp,%edi // Destination
|
||||
rep // Copy
|
||||
movsb // them
|
||||
#ifdef BTXLDR_VERBOSE
|
||||
movl $m_rel_args,%esi # Display
|
||||
movl %ebp,%eax # argument
|
||||
call hexout # relocation
|
||||
call putstr # message
|
||||
movl $m_rel_args,%esi // Display
|
||||
movl %ebp,%eax // argument
|
||||
call hexout // relocation
|
||||
call putstr // message
|
||||
#endif
|
||||
/*
|
||||
* Set up BTX kernel.
|
||||
*/
|
||||
movl $MEM_ESP,%esp # Set up new stack
|
||||
movl $MEM_DATA,%ebx # Data segment
|
||||
movl $m_vers,%esi # Display BTX
|
||||
call putstr # version message
|
||||
movb 0x5(%ebx),%al # Get major version
|
||||
addb $'0',%al # Display
|
||||
call putchr # it
|
||||
movb $'.',%al # And a
|
||||
call putchr # dot
|
||||
movb 0x6(%ebx),%al # Get minor
|
||||
xorb %ah,%ah # version
|
||||
movb $0xa,%dl # Divide
|
||||
divb %dl,%al # by 10
|
||||
addb $'0',%al # Display
|
||||
call putchr # tens
|
||||
movb %ah,%al # Get units
|
||||
addb $'0',%al # Display
|
||||
call putchr # units
|
||||
call putstr # End message
|
||||
movl %ebx,%esi # BTX image
|
||||
movzwl 0x8(%ebx),%edi # Compute
|
||||
orl $PAG_SIZ/PAG_ENT-1,%edi # the
|
||||
incl %edi # BTX
|
||||
shll $0x2,%edi # load
|
||||
addl $MEM_TBL,%edi # address
|
||||
pushl %edi # Save load address
|
||||
movzwl 0xa(%ebx),%ecx # Image size
|
||||
movl $MEM_ESP,%esp // Set up new stack
|
||||
movl $MEM_DATA,%ebx // Data segment
|
||||
movl $m_vers,%esi // Display BTX
|
||||
call putstr // version message
|
||||
movb 0x5(%ebx),%al // Get major version
|
||||
addb $'0',%al // Display
|
||||
call putchr // it
|
||||
movb $'.',%al // And a
|
||||
call putchr // dot
|
||||
movb 0x6(%ebx),%al // Get minor
|
||||
xorb %ah,%ah // version
|
||||
movb $0xa,%dl // Divide
|
||||
divb %dl,%al // by 10
|
||||
addb $'0',%al // Display
|
||||
call putchr // tens
|
||||
movb %ah,%al // Get units
|
||||
addb $'0',%al // Display
|
||||
call putchr // units
|
||||
call putstr // End message
|
||||
movl %ebx,%esi // BTX image
|
||||
movzwl 0x8(%ebx),%edi // Compute
|
||||
orl $PAG_SIZ/PAG_ENT-1,%edi // the
|
||||
incl %edi // BTX
|
||||
shll $0x2,%edi // load
|
||||
addl $MEM_TBL,%edi // address
|
||||
pushl %edi // Save load address
|
||||
movzwl 0xa(%ebx),%ecx // Image size
|
||||
#ifdef BTXLDR_VERBOSE
|
||||
pushl %ecx # Save image size
|
||||
pushl %ecx // Save image size
|
||||
#endif
|
||||
rep # Relocate
|
||||
movsb # BTX
|
||||
movl %esi,%ebx # Keep place
|
||||
rep // Relocate
|
||||
movsb // BTX
|
||||
movl %esi,%ebx // Keep place
|
||||
#ifdef BTXLDR_VERBOSE
|
||||
movl $m_rel_btx,%esi # Restore
|
||||
popl %eax # parameters
|
||||
call hexout # and
|
||||
movl $m_rel_btx,%esi // Restore
|
||||
popl %eax // parameters
|
||||
call hexout // and
|
||||
#endif
|
||||
popl %ebp # display
|
||||
popl %ebp // display
|
||||
#ifdef BTXLDR_VERBOSE
|
||||
movl %ebp,%eax # the
|
||||
call hexout # relocation
|
||||
call putstr # message
|
||||
movl %ebp,%eax // the
|
||||
call hexout // relocation
|
||||
call putstr // message
|
||||
#endif
|
||||
addl $PAG_SIZ,%ebp # Display
|
||||
addl $PAG_SIZ,%ebp // Display
|
||||
#ifdef BTXLDR_VERBOSE
|
||||
movl $m_base,%esi # the
|
||||
movl %ebp,%eax # user
|
||||
call hexout # base
|
||||
call putstr # address
|
||||
movl $m_base,%esi // the
|
||||
movl %ebp,%eax // user
|
||||
call hexout // base
|
||||
call putstr // address
|
||||
#endif
|
||||
/*
|
||||
* Set up ELF-format client program.
|
||||
*/
|
||||
cmpl $0x464c457f,(%ebx) # ELF magic number?
|
||||
je start.3 # Yes
|
||||
movl $e_fmt,%esi # Display error
|
||||
call putstr # message
|
||||
start.2: jmp start.2 # Hang
|
||||
cmpl $0x464c457f,(%ebx) // ELF magic number?
|
||||
je start.3 // Yes
|
||||
movl $e_fmt,%esi // Display error
|
||||
call putstr // message
|
||||
start.2: jmp start.2 // Hang
|
||||
start.3:
|
||||
#ifdef BTXLDR_VERBOSE
|
||||
movl $m_elf,%esi # Display ELF
|
||||
call putstr # message
|
||||
movl $m_segs,%esi # Format string
|
||||
movl $m_elf,%esi // Display ELF
|
||||
call putstr // message
|
||||
movl $m_segs,%esi // Format string
|
||||
#endif
|
||||
movl $0x2,%edi # Segment count
|
||||
movl 0x1c(%ebx),%edx # Get e_phoff
|
||||
addl %ebx,%edx # To pointer
|
||||
movzwl 0x2c(%ebx),%ecx # Get e_phnum
|
||||
start.4: cmpl $0x1,(%edx) # Is p_type PT_LOAD?
|
||||
jne start.6 # No
|
||||
movl $0x2,%edi // Segment count
|
||||
movl 0x1c(%ebx),%edx // Get e_phoff
|
||||
addl %ebx,%edx // To pointer
|
||||
movzwl 0x2c(%ebx),%ecx // Get e_phnum
|
||||
start.4: cmpl $0x1,(%edx) // Is p_type PT_LOAD?
|
||||
jne start.6 // No
|
||||
#ifdef BTXLDR_VERBOSE
|
||||
movl 0x4(%edx),%eax # Display
|
||||
call hexout # p_offset
|
||||
movl 0x8(%edx),%eax # Display
|
||||
call hexout # p_vaddr
|
||||
movl 0x10(%edx),%eax # Display
|
||||
call hexout # p_filesz
|
||||
movl 0x14(%edx),%eax # Display
|
||||
call hexout # p_memsz
|
||||
call putstr # End message
|
||||
movl 0x4(%edx),%eax // Display
|
||||
call hexout // p_offset
|
||||
movl 0x8(%edx),%eax // Display
|
||||
call hexout // p_vaddr
|
||||
movl 0x10(%edx),%eax // Display
|
||||
call hexout // p_filesz
|
||||
movl 0x14(%edx),%eax // Display
|
||||
call hexout // p_memsz
|
||||
call putstr // End message
|
||||
#endif
|
||||
pushl %esi # Save
|
||||
pushl %edi # working
|
||||
pushl %ecx # registers
|
||||
movl 0x4(%edx),%esi # Get p_offset
|
||||
addl %ebx,%esi # as pointer
|
||||
movl 0x8(%edx),%edi # Get p_vaddr
|
||||
addl %ebp,%edi # as pointer
|
||||
movl 0x10(%edx),%ecx # Get p_filesz
|
||||
rep # Set up
|
||||
movsb # segment
|
||||
movl 0x14(%edx),%ecx # Any bytes
|
||||
subl 0x10(%edx),%ecx # to zero?
|
||||
jz start.5 # No
|
||||
xorb %al,%al # Then
|
||||
rep # zero
|
||||
stosb # them
|
||||
start.5: popl %ecx # Restore
|
||||
popl %edi # working
|
||||
popl %esi # registers
|
||||
decl %edi # Segments to do
|
||||
je start.7 # If none
|
||||
start.6: addl $0x20,%edx # To next entry
|
||||
loop start.4 # Till done
|
||||
pushl %esi // Save
|
||||
pushl %edi // working
|
||||
pushl %ecx // registers
|
||||
movl 0x4(%edx),%esi // Get p_offset
|
||||
addl %ebx,%esi // as pointer
|
||||
movl 0x8(%edx),%edi // Get p_vaddr
|
||||
addl %ebp,%edi // as pointer
|
||||
movl 0x10(%edx),%ecx // Get p_filesz
|
||||
rep // Set up
|
||||
movsb // segment
|
||||
movl 0x14(%edx),%ecx // Any bytes
|
||||
subl 0x10(%edx),%ecx // to zero?
|
||||
jz start.5 // No
|
||||
xorb %al,%al // Then
|
||||
rep // zero
|
||||
stosb // them
|
||||
start.5: popl %ecx // Restore
|
||||
popl %edi // working
|
||||
popl %esi // registers
|
||||
decl %edi // Segments to do
|
||||
je start.7 // If none
|
||||
start.6: addl $0x20,%edx // To next entry
|
||||
loop start.4 // Till done
|
||||
start.7:
|
||||
#ifdef BTXLDR_VERBOSE
|
||||
movl $m_done,%esi # Display done
|
||||
call putstr # message
|
||||
movl $m_done,%esi // Display done
|
||||
call putstr // message
|
||||
#endif
|
||||
movl $start.8,%esi # Real mode stub
|
||||
movl $MEM_STUB,%edi # Destination
|
||||
movl $start.9-start.8,%ecx # Size
|
||||
rep # Relocate
|
||||
movsb # it
|
||||
ljmp $SEL_RCODE,$MEM_STUB # To 16-bit code
|
||||
movl $start.8,%esi // Real mode stub
|
||||
movl $MEM_STUB,%edi // Destination
|
||||
movl $start.9-start.8,%ecx // Size
|
||||
rep // Relocate
|
||||
movsb // it
|
||||
ljmp $SEL_RCODE,$MEM_STUB // To 16-bit code
|
||||
.code16
|
||||
start.8: xorw %ax,%ax # Data
|
||||
movb $SEL_RDATA,%al # selector
|
||||
movw %ax,%ss # Reload SS
|
||||
movw %ax,%ds # Reset
|
||||
movw %ax,%es # other
|
||||
movw %ax,%fs # segment
|
||||
movw %ax,%gs # limits
|
||||
movl %cr0,%eax # Switch to
|
||||
decw %ax # real
|
||||
movl %eax,%cr0 # mode
|
||||
ljmp $0,$MEM_ENTRY # Jump to BTX entry point
|
||||
start.8: xorw %ax,%ax // Data
|
||||
movb $SEL_RDATA,%al // selector
|
||||
movw %ax,%ss // Reload SS
|
||||
movw %ax,%ds // Reset
|
||||
movw %ax,%es // other
|
||||
movw %ax,%fs // segment
|
||||
movw %ax,%gs // limits
|
||||
movl %cr0,%eax // Switch to
|
||||
decw %ax // real
|
||||
movl %eax,%cr0 // mode
|
||||
ljmp $0,$MEM_ENTRY // Jump to BTX entry point
|
||||
start.9:
|
||||
.code32
|
||||
/*
|
||||
* Output message [ESI] followed by EAX in hex.
|
||||
*/
|
||||
hexout: pushl %eax # Save
|
||||
call putstr # Display message
|
||||
popl %eax # Restore
|
||||
pushl %esi # Save
|
||||
pushl %edi # caller's
|
||||
movl $buf,%edi # Buffer
|
||||
pushl %edi # Save
|
||||
call hex32 # To hex
|
||||
xorb %al,%al # Terminate
|
||||
stosb # string
|
||||
popl %esi # Restore
|
||||
hexout.1: lodsb # Get a char
|
||||
cmpb $'0',%al # Leading zero?
|
||||
je hexout.1 # Yes
|
||||
testb %al,%al # End of string?
|
||||
jne hexout.2 # No
|
||||
decl %esi # Undo
|
||||
hexout.2: decl %esi # Adjust for inc
|
||||
call putstr # Display hex
|
||||
popl %edi # Restore
|
||||
popl %esi # caller's
|
||||
ret # To caller
|
||||
hexout: pushl %eax // Save
|
||||
call putstr // Display message
|
||||
popl %eax // Restore
|
||||
pushl %esi // Save
|
||||
pushl %edi // caller's
|
||||
movl $buf,%edi // Buffer
|
||||
pushl %edi // Save
|
||||
call hex32 // To hex
|
||||
xorb %al,%al // Terminate
|
||||
stosb // string
|
||||
popl %esi // Restore
|
||||
hexout.1: lodsb // Get a char
|
||||
cmpb $'0',%al // Leading zero?
|
||||
je hexout.1 // Yes
|
||||
testb %al,%al // End of string?
|
||||
jne hexout.2 // No
|
||||
decl %esi // Undo
|
||||
hexout.2: decl %esi // Adjust for inc
|
||||
call putstr // Display hex
|
||||
popl %edi // Restore
|
||||
popl %esi // caller's
|
||||
ret // To caller
|
||||
/*
|
||||
* Output zero-terminated string [ESI] to the console.
|
||||
*/
|
||||
putstr.0: call putchr # Output char
|
||||
putstr: lodsb # Load char
|
||||
testb %al,%al # End of string?
|
||||
jne putstr.0 # No
|
||||
ret # To caller
|
||||
putstr.0: call putchr // Output char
|
||||
putstr: lodsb // Load char
|
||||
testb %al,%al // End of string?
|
||||
jne putstr.0 // No
|
||||
ret // To caller
|
||||
/*
|
||||
* Output character AL to the console.
|
||||
*/
|
||||
putchr: pusha # Save
|
||||
xorl %ecx,%ecx # Zero for loops
|
||||
movb $SCR_MAT,%ah # Mode/attribute
|
||||
movl $BDA_POS,%ebx # BDA pointer
|
||||
movw (%ebx),%dx # Cursor position
|
||||
movl $0xb8000,%edi # Regen buffer (color)
|
||||
cmpb %ah,BDA_SCR-BDA_POS(%ebx) # Mono mode?
|
||||
jne putchr.1 # No
|
||||
xorw %di,%di # Regen buffer (mono)
|
||||
putchr.1: cmpb $0xa,%al # New line?
|
||||
je putchr.2 # Yes
|
||||
xchgl %eax,%ecx # Save char
|
||||
movb $SCR_COL,%al # Columns per row
|
||||
mulb %dh # * row position
|
||||
addb %dl,%al # + column
|
||||
adcb $0x0,%ah # position
|
||||
shll %eax # * 2
|
||||
xchgl %eax,%ecx # Swap char, offset
|
||||
movw %ax,(%edi,%ecx,1) # Write attr:char
|
||||
incl %edx # Bump cursor
|
||||
cmpb $SCR_COL,%dl # Beyond row?
|
||||
jb putchr.3 # No
|
||||
putchr.2: xorb %dl,%dl # Zero column
|
||||
incb %dh # Bump row
|
||||
putchr.3: cmpb $SCR_ROW,%dh # Beyond screen?
|
||||
jb putchr.4 # No
|
||||
leal 2*SCR_COL(%edi),%esi # New top line
|
||||
movw $(SCR_ROW-1)*SCR_COL/2,%cx # Words to move
|
||||
rep # Scroll
|
||||
movsl # screen
|
||||
movb $' ',%al # Space
|
||||
movb $SCR_COL,%cl # Columns to clear
|
||||
rep # Clear
|
||||
stosw # line
|
||||
movb $SCR_ROW-1,%dh # Bottom line
|
||||
putchr.4: movw %dx,(%ebx) # Update position
|
||||
popa # Restore
|
||||
ret # To caller
|
||||
putchr: pusha // Save
|
||||
xorl %ecx,%ecx // Zero for loops
|
||||
movb $SCR_MAT,%ah // Mode/attribute
|
||||
movl $BDA_POS,%ebx // BDA pointer
|
||||
movw (%ebx),%dx // Cursor position
|
||||
movl $0xb8000,%edi // Regen buffer (color)
|
||||
cmpb %ah,BDA_SCR-BDA_POS(%ebx) // Mono mode?
|
||||
jne putchr.1 // No
|
||||
xorw %di,%di // Regen buffer (mono)
|
||||
putchr.1: cmpb $0xa,%al // New line?
|
||||
je putchr.2 // Yes
|
||||
xchgl %eax,%ecx // Save char
|
||||
movb $SCR_COL,%al // Columns per row
|
||||
mulb %dh // * row position
|
||||
addb %dl,%al // + column
|
||||
adcb $0x0,%ah // position
|
||||
shll %eax // * 2
|
||||
xchgl %eax,%ecx // Swap char, offset
|
||||
movw %ax,(%edi,%ecx,1) // Write attr:char
|
||||
incl %edx // Bump cursor
|
||||
cmpb $SCR_COL,%dl // Beyond row?
|
||||
jb putchr.3 // No
|
||||
putchr.2: xorb %dl,%dl // Zero column
|
||||
incb %dh // Bump row
|
||||
putchr.3: cmpb $SCR_ROW,%dh // Beyond screen?
|
||||
jb putchr.4 // No
|
||||
leal 2*SCR_COL(%edi),%esi // New top line
|
||||
movw $(SCR_ROW-1)*SCR_COL/2,%cx // Words to move
|
||||
rep // Scroll
|
||||
movsl // screen
|
||||
movb $' ',%al // Space
|
||||
movb $SCR_COL,%cl // Columns to clear
|
||||
rep // Clear
|
||||
stosw // line
|
||||
movb $SCR_ROW-1,%dh // Bottom line
|
||||
putchr.4: movw %dx,(%ebx) // Update position
|
||||
popa // Restore
|
||||
ret // To caller
|
||||
/*
|
||||
* Convert EAX, AX, or AL to hex, saving the result to [EDI].
|
||||
*/
|
||||
hex32: pushl %eax # Save
|
||||
shrl $0x10,%eax # Do upper
|
||||
call hex16 # 16
|
||||
popl %eax # Restore
|
||||
hex16: call hex16.1 # Do upper 8
|
||||
hex16.1: xchgb %ah,%al # Save/restore
|
||||
hex8: pushl %eax # Save
|
||||
shrb $0x4,%al # Do upper
|
||||
call hex8.1 # 4
|
||||
popl %eax # Restore
|
||||
hex8.1: andb $0xf,%al # Get lower 4
|
||||
cmpb $0xa,%al # Convert
|
||||
sbbb $0x69,%al # to hex
|
||||
das # digit
|
||||
orb $0x20,%al # To lower case
|
||||
stosb # Save char
|
||||
ret # (Recursive)
|
||||
hex32: pushl %eax // Save
|
||||
shrl $0x10,%eax // Do upper
|
||||
call hex16 // 16
|
||||
popl %eax // Restore
|
||||
hex16: call hex16.1 // Do upper 8
|
||||
hex16.1: xchgb %ah,%al // Save/restore
|
||||
hex8: pushl %eax // Save
|
||||
shrb $0x4,%al // Do upper
|
||||
call hex8.1 // 4
|
||||
popl %eax // Restore
|
||||
hex8.1: andb $0xf,%al // Get lower 4
|
||||
cmpb $0xa,%al // Convert
|
||||
sbbb $0x69,%al // to hex
|
||||
das // digit
|
||||
orb $0x20,%al // To lower case
|
||||
stosb // Save char
|
||||
ret // (Recursive)
|
||||
|
||||
.data
|
||||
.p2align 4
|
||||
/*
|
||||
* Global descriptor table.
|
||||
*/
|
||||
gdt: .word 0x0,0x0,0x0,0x0 # Null entry
|
||||
.word 0xffff,0x0,0x9a00,0xcf # SEL_SCODE
|
||||
.word 0xffff,0x0,0x9200,0xcf # SEL_SDATA
|
||||
.word 0xffff,0x0,0x9a00,0x0 # SEL_RCODE
|
||||
.word 0xffff,0x0,0x9200,0x0 # SEL_RDATA
|
||||
gdt: .word 0x0,0x0,0x0,0x0 // Null entry
|
||||
.word 0xffff,0x0,0x9a00,0xcf // SEL_SCODE
|
||||
.word 0xffff,0x0,0x9200,0xcf // SEL_SDATA
|
||||
.word 0xffff,0x0,0x9a00,0x0 // SEL_RCODE
|
||||
.word 0xffff,0x0,0x9200,0x0 // SEL_RDATA
|
||||
gdt.1:
|
||||
gdtdesc: .word gdt.1-gdt-1 # Limit
|
||||
.long gdt # Base
|
||||
gdtdesc: .word gdt.1-gdt-1 // Limit
|
||||
.long gdt // Base
|
||||
/*
|
||||
* Messages.
|
||||
*/
|
||||
@ -393,4 +393,4 @@ m_done: .asciz "Loading complete\n"
|
||||
/*
|
||||
* Uninitialized data area.
|
||||
*/
|
||||
buf: # Scratch buffer
|
||||
buf: // Scratch buffer
|
||||
|
||||
@ -56,15 +56,15 @@ PT2:
|
||||
|
||||
gdtdesc:
|
||||
.word gdtend - gdt
|
||||
.long VTOP(gdt) # low
|
||||
.long 0 # high
|
||||
.long VTOP(gdt) // low
|
||||
.long 0 // high
|
||||
|
||||
gdt:
|
||||
.long 0 # null descriptor
|
||||
.long 0 // null descriptor
|
||||
.long 0
|
||||
.long 0x00000000 # %cs
|
||||
.long 0x00000000 // %cs
|
||||
.long 0x00209800
|
||||
.long 0x00000000 # %ds
|
||||
.long 0x00000000 // %ds
|
||||
.long 0x00008000
|
||||
gdtend:
|
||||
|
||||
|
||||
@ -19,7 +19,7 @@
|
||||
* This simple program is a preloader for the normal boot3 loader. It is simply
|
||||
* prepended to the beginning of a fully built and btxld'd loader. It then
|
||||
* copies the loader to the address boot2 normally loads it, emulates the
|
||||
* boot[12] environment (protected mode, a bootinfo struct, etc.), and then jumps
|
||||
* boot[12] environment (protected mode, a bootinfo struct, etc.) and then jumps
|
||||
* to the start of btxldr to start the boot process. This method allows a stock
|
||||
* /boot/loader to be booted over the network via PXE w/o having to write a
|
||||
* separate PXE-aware client just to load the loader.
|
||||
@ -28,45 +28,45 @@
|
||||
/*
|
||||
* Memory locations.
|
||||
*/
|
||||
.set MEM_PAGE_SIZE,0x1000 # memory page size, 4k
|
||||
.set MEM_ARG,0x900 # Arguments at start
|
||||
.set MEM_ARG_BTX,0xa100 # Where we move them to so the
|
||||
# BTX client can see them
|
||||
.set MEM_ARG_SIZE,0x18 # Size of the arguments
|
||||
.set MEM_BTX_ADDRESS,0x9000 # where BTX lives
|
||||
.set MEM_BTX_ENTRY,0x9010 # where BTX starts to execute
|
||||
.set MEM_BTX_OFFSET,MEM_PAGE_SIZE # offset of BTX in the loader
|
||||
.set MEM_BTX_CLIENT,0xa000 # where BTX clients live
|
||||
.set MEM_BIOS_KEYBOARD,0x496 # BDA byte with keyboard bit
|
||||
.set MEM_PAGE_SIZE,0x1000 // memory page size, 4k
|
||||
.set MEM_ARG,0x900 // Arguments at start
|
||||
.set MEM_ARG_BTX,0xa100 // Where we move them to so the
|
||||
// BTX client can see them
|
||||
.set MEM_ARG_SIZE,0x18 // Size of the arguments
|
||||
.set MEM_BTX_ADDRESS,0x9000 // where BTX lives
|
||||
.set MEM_BTX_ENTRY,0x9010 // where BTX starts to execute
|
||||
.set MEM_BTX_OFFSET,MEM_PAGE_SIZE // offset of BTX in the loader
|
||||
.set MEM_BTX_CLIENT,0xa000 // where BTX clients live
|
||||
.set MEM_BIOS_KEYBOARD,0x496 // BDA byte with keyboard bit
|
||||
/*
|
||||
* a.out header fields
|
||||
*/
|
||||
.set AOUT_TEXT,0x04 # text segment size
|
||||
.set AOUT_DATA,0x08 # data segment size
|
||||
.set AOUT_BSS,0x0c # zero'd BSS size
|
||||
.set AOUT_SYMBOLS,0x10 # symbol table
|
||||
.set AOUT_ENTRY,0x14 # entry point
|
||||
.set AOUT_HEADER,MEM_PAGE_SIZE # size of the a.out header
|
||||
.set AOUT_TEXT,0x04 // text segment size
|
||||
.set AOUT_DATA,0x08 // data segment size
|
||||
.set AOUT_BSS,0x0c // zero'd BSS size
|
||||
.set AOUT_SYMBOLS,0x10 // symbol table
|
||||
.set AOUT_ENTRY,0x14 // entry point
|
||||
.set AOUT_HEADER,MEM_PAGE_SIZE // size of the a.out header
|
||||
/*
|
||||
* Flags for kargs->bootflags
|
||||
*/
|
||||
.set KARGS_FLAGS_PXE,0x2 # flag to indicate booting from
|
||||
# PXE loader
|
||||
.set KARGS_FLAGS_PXE,0x2 // flag to indicate booting from
|
||||
// PXE loader
|
||||
/*
|
||||
* Boot howto bits
|
||||
*/
|
||||
.set RB_SERIAL,0x1000 # serial console
|
||||
.set RB_SERIAL,0x1000 // serial console
|
||||
/*
|
||||
* Segment selectors.
|
||||
*/
|
||||
.set SEL_SDATA,0x8 # Supervisor data
|
||||
.set SEL_RDATA,0x10 # Real mode data
|
||||
.set SEL_SCODE,0x18 # PM-32 code
|
||||
.set SEL_SCODE16,0x20 # PM-16 code
|
||||
.set SEL_SDATA,0x8 // Supervisor data
|
||||
.set SEL_RDATA,0x10 // Real mode data
|
||||
.set SEL_SCODE,0x18 // PM-32 code
|
||||
.set SEL_SCODE16,0x20 // PM-16 code
|
||||
/*
|
||||
* BTX constants
|
||||
*/
|
||||
.set INT_SYS,0x30 # BTX syscall interrupt
|
||||
.set INT_SYS,0x30 // BTX syscall interrupt
|
||||
/*
|
||||
* Bit in MEM_BIOS_KEYBOARD that is set if an enhanced keyboard is present
|
||||
*/
|
||||
@ -81,186 +81,190 @@
|
||||
/*
|
||||
* BTX program loader for PXE network booting
|
||||
*/
|
||||
start: cld # string ops inc
|
||||
xorw %ax, %ax # zero %ax
|
||||
movw %ax, %ss # setup the
|
||||
movw $start, %sp # stack
|
||||
movw %es, %cx # save PXENV+ segment
|
||||
movw %ax, %ds # setup the
|
||||
movw %ax, %es # data segments
|
||||
andl $0xffff, %ecx # clear upper words
|
||||
andl $0xffff, %ebx # of %ebx and %ecx
|
||||
shll $4, %ecx # calculate the offset of
|
||||
addl %ebx, %ecx # the PXENV+ struct and
|
||||
pushl %ecx # save it on the stack
|
||||
movw $welcome_msg, %si # %ds:(%si) -> welcome message
|
||||
callw putstr # display the welcome message
|
||||
start: cld // string ops inc
|
||||
xorw %ax, %ax // zero %ax
|
||||
movw %ax, %ss // setup the
|
||||
movw $start, %sp // stack
|
||||
movw %es, %cx // save PXENV+ segment
|
||||
movw %ax, %ds // setup the
|
||||
movw %ax, %es // data segments
|
||||
andl $0xffff, %ecx // clear upper words
|
||||
andl $0xffff, %ebx // of %ebx and %ecx
|
||||
shll $4, %ecx // calculate the offset of
|
||||
addl %ebx, %ecx // the PXENV+ struct and
|
||||
pushl %ecx // save it on the stack
|
||||
movw $welcome_msg, %si // %ds:(%si) -> welcome message
|
||||
callw putstr // display the welcome message
|
||||
/*
|
||||
* Setup the arguments that the loader is expecting from boot[12]
|
||||
*/
|
||||
movw $bootinfo_msg, %si # %ds:(%si) -> boot args message
|
||||
callw putstr # display the message
|
||||
movw $MEM_ARG, %bx # %ds:(%bx) -> boot args
|
||||
movw %bx, %di # %es:(%di) -> boot args
|
||||
xorl %eax, %eax # zero %eax
|
||||
movw $(MEM_ARG_SIZE/4), %cx # Size of arguments in 32-bit
|
||||
# dwords
|
||||
rep # Clear the arguments
|
||||
stosl # to zero
|
||||
orb $KARGS_FLAGS_PXE, 0x8(%bx) # kargs->bootflags |=
|
||||
# KARGS_FLAGS_PXE
|
||||
popl 0xc(%bx) # kargs->pxeinfo = *PXENV+
|
||||
movw $bootinfo_msg, %si // %ds:(%si) -> boot args
|
||||
// message
|
||||
callw putstr // display the message
|
||||
movw $MEM_ARG, %bx // %ds:(%bx) -> boot args
|
||||
movw %bx, %di // %es:(%di) -> boot args
|
||||
xorl %eax, %eax // zero %eax
|
||||
movw $(MEM_ARG_SIZE/4), %cx // Size of arguments in 32-bit
|
||||
// dwords
|
||||
rep // Clear the arguments
|
||||
stosl // to zero
|
||||
orb $KARGS_FLAGS_PXE, 0x8(%bx) // kargs->bootflags |=
|
||||
// KARGS_FLAGS_PXE
|
||||
popl 0xc(%bx) // kargs->pxeinfo = *PXENV+
|
||||
#ifdef ALWAYS_SERIAL
|
||||
/*
|
||||
* set the RBX_SERIAL bit in the howto byte.
|
||||
*/
|
||||
orl $RB_SERIAL, (%bx) # enable serial console
|
||||
orl $RB_SERIAL, (%bx) // enable serial console
|
||||
#endif
|
||||
#ifdef PROBE_KEYBOARD
|
||||
/*
|
||||
* Look at the BIOS data area to see if we have an enhanced keyboard. If not,
|
||||
* set the RBX_SERIAL bit in the howto byte.
|
||||
*/
|
||||
testb $KEYBOARD_BIT, MEM_BIOS_KEYBOARD # keyboard present?
|
||||
jnz keyb # yes, so skip
|
||||
orl $RB_SERIAL, (%bx) # enable serial console
|
||||
testb $KEYBOARD_BIT, MEM_BIOS_KEYBOARD // keyboard present?
|
||||
jnz keyb // yes, so skip
|
||||
orl $RB_SERIAL, (%bx) // enable serial console
|
||||
keyb:
|
||||
#endif
|
||||
/*
|
||||
* Turn on the A20 address line
|
||||
*/
|
||||
callw seta20 # Turn A20 on
|
||||
callw seta20 // Turn A20 on
|
||||
/*
|
||||
* Relocate the loader and BTX using a very lazy protected mode
|
||||
*/
|
||||
movw $relocate_msg, %si # Display the
|
||||
callw putstr # relocation message
|
||||
movl end+AOUT_ENTRY, %edi # %edi is the destination
|
||||
movl $(end+AOUT_HEADER), %esi # %esi is
|
||||
# the start of the text
|
||||
# segment
|
||||
movl end+AOUT_TEXT, %ecx # %ecx = length of the text
|
||||
# segment
|
||||
lgdt gdtdesc # setup our own gdt
|
||||
cli # turn off interrupts
|
||||
movl %cr0, %eax # Turn on
|
||||
orb $0x1, %al # protected
|
||||
movl %eax, %cr0 # mode
|
||||
ljmp $SEL_SCODE,$pm_start # long jump to clear the
|
||||
# instruction pre-fetch queue
|
||||
movw $relocate_msg, %si // Display the
|
||||
callw putstr // relocation message
|
||||
movl end+AOUT_ENTRY, %edi // %edi is the destination
|
||||
movl $(end+AOUT_HEADER), %esi // %esi is
|
||||
// the start of the text
|
||||
// segment
|
||||
movl end+AOUT_TEXT, %ecx // %ecx = length of the text
|
||||
// segment
|
||||
lgdt gdtdesc // setup our own gdt
|
||||
cli // turn off interrupts
|
||||
movl %cr0, %eax // Turn on
|
||||
orb $0x1, %al // protected
|
||||
movl %eax, %cr0 // mode
|
||||
ljmp $SEL_SCODE,$pm_start // long jump to clear the
|
||||
// instruction pre-fetch queue
|
||||
.code32
|
||||
pm_start: movw $SEL_SDATA, %ax # Initialize
|
||||
movw %ax, %ds # %ds and
|
||||
movw %ax, %es # %es to a flat selector
|
||||
rep # Relocate the
|
||||
movsb # text segment
|
||||
addl $(MEM_PAGE_SIZE - 1), %edi # pad %edi out to a new page
|
||||
andl $~(MEM_PAGE_SIZE - 1), %edi # for the data segment
|
||||
movl end+AOUT_DATA, %ecx # size of the data segment
|
||||
rep # Relocate the
|
||||
movsb # data segment
|
||||
movl end+AOUT_BSS, %ecx # size of the bss
|
||||
xorl %eax, %eax # zero %eax
|
||||
addb $3, %cl # round %ecx up to
|
||||
shrl $2, %ecx # a multiple of 4
|
||||
rep # zero the
|
||||
stosl # bss
|
||||
movl end+AOUT_ENTRY, %esi # %esi -> relocated loader
|
||||
addl $MEM_BTX_OFFSET, %esi # %esi -> BTX in the loader
|
||||
movl $MEM_BTX_ADDRESS, %edi # %edi -> where BTX needs to go
|
||||
movzwl 0xa(%esi), %ecx # %ecx -> length of BTX
|
||||
rep # Relocate
|
||||
movsb # BTX
|
||||
ljmp $SEL_SCODE16,$pm_16 # Jump to 16-bit PM
|
||||
pm_start: movw $SEL_SDATA, %ax // Initialize
|
||||
movw %ax, %ds // %ds and
|
||||
movw %ax, %es // %es to a flat selector
|
||||
rep // Relocate the
|
||||
movsb // text segment
|
||||
addl $(MEM_PAGE_SIZE - 1), %edi // pad %edi out to a new page
|
||||
andl $~(MEM_PAGE_SIZE - 1), %edi // for the data segment
|
||||
movl end+AOUT_DATA, %ecx // size of the data segment
|
||||
rep // Relocate the
|
||||
movsb // data segment
|
||||
movl end+AOUT_BSS, %ecx // size of the bss
|
||||
xorl %eax, %eax // zero %eax
|
||||
addb $3, %cl // round %ecx up to
|
||||
shrl $2, %ecx // a multiple of 4
|
||||
rep // zero the
|
||||
stosl // bss
|
||||
movl end+AOUT_ENTRY, %esi // %esi -> relocated loader
|
||||
addl $MEM_BTX_OFFSET, %esi // %esi -> BTX in the loader
|
||||
movl $MEM_BTX_ADDRESS, %edi // %edi -> where BTX needs to go
|
||||
movzwl 0xa(%esi), %ecx // %ecx -> length of BTX
|
||||
rep // Relocate
|
||||
movsb // BTX
|
||||
ljmp $SEL_SCODE16,$pm_16 // Jump to 16-bit PM
|
||||
.code16
|
||||
pm_16: movw $SEL_RDATA, %ax # Initialize
|
||||
movw %ax, %ds # %ds and
|
||||
movw %ax, %es # %es to a real mode selector
|
||||
movl %cr0, %eax # Turn off
|
||||
andb $~0x1, %al # protected
|
||||
movl %eax, %cr0 # mode
|
||||
ljmp $0,$pm_end # Long jump to clear the
|
||||
# instruction pre-fetch queue
|
||||
pm_end: sti # Turn interrupts back on now
|
||||
pm_16: movw $SEL_RDATA, %ax // Initialize
|
||||
movw %ax, %ds // %ds and
|
||||
movw %ax, %es // %es to a real mode selector
|
||||
movl %cr0, %eax // Turn off
|
||||
andb $~0x1, %al // protected
|
||||
movl %eax, %cr0 // mode
|
||||
ljmp $0,$pm_end // Long jump to clear the
|
||||
// instruction pre-fetch queue
|
||||
pm_end: sti // Turn interrupts back on now
|
||||
/*
|
||||
* Copy the BTX client to MEM_BTX_CLIENT
|
||||
*/
|
||||
xorw %ax, %ax # zero %ax and set
|
||||
movw %ax, %ds # %ds and %es
|
||||
movw %ax, %es # to segment 0
|
||||
movw $MEM_BTX_CLIENT, %di # Prepare to relocate
|
||||
movw $btx_client, %si # the simple btx client
|
||||
movw $(btx_client_end-btx_client), %cx # length of btx client
|
||||
rep # Relocate the
|
||||
movsb # simple BTX client
|
||||
xorw %ax, %ax // zero %ax and set
|
||||
movw %ax, %ds // %ds and %es
|
||||
movw %ax, %es // to segment 0
|
||||
movw $MEM_BTX_CLIENT, %di // Prepare to relocate
|
||||
movw $btx_client, %si // the simple btx client
|
||||
movw $(btx_client_end-btx_client), %cx // length of btx client
|
||||
rep // Relocate the
|
||||
movsb // simple BTX client
|
||||
/*
|
||||
* Copy the boot[12] args to where the BTX client can see them
|
||||
*/
|
||||
movw $MEM_ARG, %si # where the args are at now
|
||||
movw $MEM_ARG_BTX, %di # where the args are moving to
|
||||
movw $(MEM_ARG_SIZE/4), %cx # size of the arguments in longs
|
||||
rep # Relocate
|
||||
movsl # the words
|
||||
movw $MEM_ARG, %si // where the args are at now
|
||||
movw $MEM_ARG_BTX, %di // where the args are moving to
|
||||
movw $(MEM_ARG_SIZE/4), %cx // size of the arguments in
|
||||
// longs
|
||||
rep // Relocate
|
||||
movsl // the words
|
||||
/*
|
||||
* Save the entry point so the client can get to it later on
|
||||
*/
|
||||
movl end+AOUT_ENTRY, %eax # load the entry point
|
||||
stosl # add it to the end of the
|
||||
# arguments
|
||||
movl end+AOUT_ENTRY, %eax // load the entry point
|
||||
stosl // add it to the end of the
|
||||
// arguments
|
||||
/*
|
||||
* Now we just start up BTX and let it do the rest
|
||||
*/
|
||||
movw $jump_message, %si # Display the
|
||||
callw putstr # jump message
|
||||
ljmp $0,$MEM_BTX_ENTRY # Jump to the BTX entry point
|
||||
movw $jump_message, %si // Display the
|
||||
callw putstr // jump message
|
||||
ljmp $0,$MEM_BTX_ENTRY // Jump to the BTX entry point
|
||||
|
||||
/*
|
||||
* Display a null-terminated string
|
||||
*/
|
||||
putstr: lodsb # load %al from %ds:(%si)
|
||||
testb %al,%al # stop at null
|
||||
jnz putc # if the char != null, output it
|
||||
retw # return when null is hit
|
||||
putc: movw $0x7,%bx # attribute for output
|
||||
movb $0xe,%ah # BIOS: put_char
|
||||
int $0x10 # call BIOS, print char in %al
|
||||
jmp putstr # keep looping
|
||||
putstr: lodsb // load %al from %ds:(%si)
|
||||
testb %al,%al // stop at null
|
||||
jnz putc // if the char != null,
|
||||
// output it
|
||||
retw // return when null is hit
|
||||
putc: movw $0x7,%bx // attribute for output
|
||||
movb $0xe,%ah // BIOS: put_char
|
||||
int $0x10 // call BIOS, print char in %al
|
||||
jmp putstr // keep looping
|
||||
|
||||
/*
|
||||
* Enable A20
|
||||
*/
|
||||
seta20: cli # Disable interrupts
|
||||
seta20.1: inb $0x64,%al # Get status
|
||||
testb $0x2,%al # Busy?
|
||||
jnz seta20.1 # Yes
|
||||
movb $0xd1,%al # Command: Write
|
||||
outb %al,$0x64 # output port
|
||||
seta20.2: inb $0x64,%al # Get status
|
||||
testb $0x2,%al # Busy?
|
||||
jnz seta20.2 # Yes
|
||||
movb $0xdf,%al # Enable
|
||||
outb %al,$0x60 # A20
|
||||
sti # Enable interrupts
|
||||
retw # To caller
|
||||
seta20: cli // Disable interrupts
|
||||
seta20.1: inb $0x64,%al // Get status
|
||||
testb $0x2,%al // Busy?
|
||||
jnz seta20.1 // Yes
|
||||
movb $0xd1,%al // Command: Write
|
||||
outb %al,$0x64 // output port
|
||||
seta20.2: inb $0x64,%al // Get status
|
||||
testb $0x2,%al // Busy?
|
||||
jnz seta20.2 // Yes
|
||||
movb $0xdf,%al // Enable
|
||||
outb %al,$0x60 // A20
|
||||
sti // Enable interrupts
|
||||
retw // To caller
|
||||
|
||||
/*
|
||||
* BTX client to start btxldr
|
||||
*/
|
||||
.code32
|
||||
btx_client: movl $(MEM_ARG_BTX-MEM_BTX_CLIENT+MEM_ARG_SIZE-4), %esi
|
||||
# %ds:(%esi) -> end
|
||||
# of boot[12] args
|
||||
movl $(MEM_ARG_SIZE/4), %ecx # Number of words to push
|
||||
std # Go backwards
|
||||
push_arg: lodsl # Read argument
|
||||
pushl %eax # Push it onto the stack
|
||||
loop push_arg # Push all of the arguments
|
||||
cld # In case anyone depends on this
|
||||
pushl MEM_ARG_BTX-MEM_BTX_CLIENT+MEM_ARG_SIZE # Entry point of
|
||||
# the loader
|
||||
pushl %eax # Emulate a near call
|
||||
movl $0x1, %eax # 'exec' system call
|
||||
int $INT_SYS # BTX system call
|
||||
// %ds:(%esi) -> end
|
||||
// of boot[12] args
|
||||
movl $(MEM_ARG_SIZE/4), %ecx // Number of words to push
|
||||
std // Go backwards
|
||||
push_arg: lodsl // Read argument
|
||||
pushl %eax // Push it onto the stack
|
||||
loop push_arg // Push all of the arguments
|
||||
cld // In case anyone depends
|
||||
// on this
|
||||
pushl MEM_ARG_BTX-MEM_BTX_CLIENT+MEM_ARG_SIZE // Entry point of
|
||||
// the loader
|
||||
pushl %eax // Emulate a near call
|
||||
movl $0x1, %eax // 'exec' system call
|
||||
int $INT_SYS // BTX system call
|
||||
btx_client_end:
|
||||
.code16
|
||||
|
||||
@ -268,17 +272,17 @@ btx_client_end:
|
||||
/*
|
||||
* Global descriptor table.
|
||||
*/
|
||||
gdt: .word 0x0,0x0,0x0,0x0 # Null entry
|
||||
.word 0xffff,0x0,0x9200,0xcf # SEL_SDATA
|
||||
.word 0xffff,0x0,0x9200,0x0 # SEL_RDATA
|
||||
.word 0xffff,0x0,0x9a00,0xcf # SEL_SCODE (32-bit)
|
||||
.word 0xffff,0x0,0x9a00,0x8f # SEL_SCODE16 (16-bit)
|
||||
gdt: .word 0x0,0x0,0x0,0x0 // Null entry
|
||||
.word 0xffff,0x0,0x9200,0xcf // SEL_SDATA
|
||||
.word 0xffff,0x0,0x9200,0x0 // SEL_RDATA
|
||||
.word 0xffff,0x0,0x9a00,0xcf // SEL_SCODE (32-bit)
|
||||
.word 0xffff,0x0,0x9a00,0x8f // SEL_SCODE16 (16-bit)
|
||||
gdt.1:
|
||||
/*
|
||||
* Pseudo-descriptors.
|
||||
*/
|
||||
gdtdesc: .word gdt.1-gdt-1 # Limit
|
||||
.long gdt # Base
|
||||
gdtdesc: .word gdt.1-gdt-1 // Limit
|
||||
.long gdt // Base
|
||||
|
||||
welcome_msg: .asciz "PXE Loader 1.00\r\n\n"
|
||||
bootinfo_msg: .asciz "Building the boot loader arguments\r\n"
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user