Switch to using C99 comments in assembler preprocessed with cpp(1).
This commit is contained in:
Ruslan Ermilov
parent
69dd73b976
commit
df1a364da7
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=128723
@ -1,430 +1,430 @@
|
||||
#
|
||||
# Copyright (c) 2002 Bruce M. Simpson
|
||||
# Copyright (c) 1998 Robert Nordier
|
||||
# All rights reserved.
|
||||
#
|
||||
# Redistribution and use in source and binary forms are freely
|
||||
# permitted provided that the above copyright notice and this
|
||||
# paragraph and the following disclaimer are duplicated in all
|
||||
# such forms.
|
||||
#
|
||||
# This software is provided "AS IS" and without any express or
|
||||
# implied warranties, including, without limitation, the implied
|
||||
# warranties of merchantability and fitness for a particular
|
||||
# purpose.
|
||||
#
|
||||
# $FreeBSD$
|
||||
#
|
||||
/*
|
||||
* Copyright (c) 2002 Bruce M. Simpson
|
||||
* Copyright (c) 1998 Robert Nordier
|
||||
* All rights reserved.
|
||||
*
|
||||
* Redistribution and use in source and binary forms are freely
|
||||
* permitted provided that the above copyright notice and this
|
||||
* paragraph and the following disclaimer are duplicated in all
|
||||
* such forms.
|
||||
*
|
||||
* This software is provided "AS IS" and without any express or
|
||||
* implied warranties, including, without limitation, the implied
|
||||
* warranties of merchantability and fitness for a particular
|
||||
* purpose.
|
||||
*
|
||||
* $FreeBSD$
|
||||
*/
|
||||
|
||||
# A 512-byte boot manager.
|
||||
/* A 512-byte boot manager. */
|
||||
#ifdef SIO
|
||||
# ... using a serial console on COM1.
|
||||
/* ... using a serial console on COM1. */
|
||||
#endif /* SIO */
|
||||
|
||||
.set NHRDRV,0x475 # Number of hard drives
|
||||
.set ORIGIN,0x600 # Execution address
|
||||
.set FAKE,0x800 # Partition entry
|
||||
.set LOAD,0x7c00 # Load address
|
||||
.set NHRDRV,0x475 // Number of hard drives
|
||||
.set ORIGIN,0x600 // Execution address
|
||||
.set FAKE,0x800 // Partition entry
|
||||
.set LOAD,0x7c00 // Load address
|
||||
|
||||
.set PRT_OFF,0x1be # Partition table
|
||||
.set PRT_OFF,0x1be // Partition table
|
||||
|
||||
.set TBL0SZ,0x3 # Table 0 size
|
||||
.set TBL1SZ,0xb # Table 1 size
|
||||
.set TBL0SZ,0x3 // Table 0 size
|
||||
.set TBL1SZ,0xb // Table 1 size
|
||||
|
||||
.set MAGIC,0xaa55 # Magic: bootable
|
||||
.set B0MAGIC,0xbb66 # Identification
|
||||
.set MAGIC,0xaa55 // Magic: bootable
|
||||
.set B0MAGIC,0xbb66 // Identification
|
||||
|
||||
.set KEY_ENTER,0x1c # Enter key scan code
|
||||
.set KEY_F1,0x3b # F1 key scan code
|
||||
.set KEY_1,0x02 # #1 key scan code
|
||||
.set KEY_ENTER,0x1c // Enter key scan code
|
||||
.set KEY_F1,0x3b // F1 key scan code
|
||||
.set KEY_1,0x02 // #1 key scan code
|
||||
|
||||
.set ASCII_BEL,0x07 # ASCII code for <BEL>
|
||||
.set ASCII_CR,0x0D # ASCII code for <CR>
|
||||
.set ASCII_BEL,0x07 // ASCII code for <BEL>
|
||||
.set ASCII_CR,0x0D // ASCII code for <CR>
|
||||
|
||||
#
|
||||
# Addresses in the sector of embedded data values.
|
||||
# Accessed with negative offsets from the end of the relocated sector (%ebp).
|
||||
#
|
||||
.set _NXTDRV,-0x48 # Next drive
|
||||
.set _OPT,-0x47 # Default option
|
||||
.set _SETDRV,-0x46 # Drive to force
|
||||
.set _FLAGS,-0x45 # Flags
|
||||
.set _TICKS,-0x44 # Timeout ticks
|
||||
.set _FAKE,0x0 # Fake partition entry
|
||||
.set _MNUOPT,0xc # Menu options
|
||||
/*
|
||||
* Addresses in the sector of embedded data values.
|
||||
* Accessed with negative offsets from the end of the relocated sector (%ebp).
|
||||
*/
|
||||
.set _NXTDRV,-0x48 // Next drive
|
||||
.set _OPT,-0x47 // Default option
|
||||
.set _SETDRV,-0x46 // Drive to force
|
||||
.set _FLAGS,-0x45 // Flags
|
||||
.set _TICKS,-0x44 // Timeout ticks
|
||||
.set _FAKE,0x0 // Fake partition entry
|
||||
.set _MNUOPT,0xc // Menu options
|
||||
|
||||
.globl start # Entry point
|
||||
.code16 # This runs in real mode
|
||||
.globl start // Entry point
|
||||
.code16 // This runs in real mode
|
||||
|
||||
#
|
||||
# Initialise segments and registers to known values.
|
||||
# segments start at 0.
|
||||
# The stack is immediately below the address we were loaded to.
|
||||
#
|
||||
start: cld # String ops inc
|
||||
xorw %ax,%ax # Zero
|
||||
movw %ax,%es # Address
|
||||
movw %ax,%ds # data
|
||||
movw %ax,%ss # Set up
|
||||
movw $LOAD,%sp # stack
|
||||
/*
|
||||
* Initialise segments and registers to known values.
|
||||
* segments start at 0.
|
||||
* The stack is immediately below the address we were loaded to.
|
||||
*/
|
||||
start: cld // String ops inc
|
||||
xorw %ax,%ax // Zero
|
||||
movw %ax,%es // Address
|
||||
movw %ax,%ds // data
|
||||
movw %ax,%ss // Set up
|
||||
movw $LOAD,%sp // stack
|
||||
|
||||
#
|
||||
# Copy this code to the address it was linked for
|
||||
#
|
||||
movw %sp,%si # Source
|
||||
movw $start,%di # Destination
|
||||
movw $0x100,%cx # Word count
|
||||
rep # Relocate
|
||||
movsw # code
|
||||
#
|
||||
# Set address for variable space beyond code, and clear it.
|
||||
# Notice that this is also used to point to the values embedded in the block,
|
||||
# by using negative offsets.
|
||||
#
|
||||
movw %di,%bp # Address variables
|
||||
movb $0x8,%cl # Words to clear
|
||||
rep # Zero
|
||||
stosw # them
|
||||
#
|
||||
# Relocate to the new copy of the code.
|
||||
#
|
||||
incb -0xe(%di) # Sector number
|
||||
jmp main-LOAD+ORIGIN # To relocated code
|
||||
/*
|
||||
* Copy this code to the address it was linked for
|
||||
*/
|
||||
movw %sp,%si // Source
|
||||
movw $start,%di // Destination
|
||||
movw $0x100,%cx // Word count
|
||||
rep // Relocate
|
||||
movsw // code
|
||||
/*
|
||||
* Set address for variable space beyond code, and clear it.
|
||||
* Notice that this is also used to point to the values embedded in the block,
|
||||
* by using negative offsets.
|
||||
*/
|
||||
movw %di,%bp // Address variables
|
||||
movb $0x8,%cl // Words to clear
|
||||
rep // Zero
|
||||
stosw // them
|
||||
/*
|
||||
* Relocate to the new copy of the code.
|
||||
*/
|
||||
incb -0xe(%di) // Sector number
|
||||
jmp main-LOAD+ORIGIN // To relocated code
|
||||
|
||||
main:
|
||||
#ifdef SIO
|
||||
#
|
||||
# Initialize the serial port.
|
||||
# Must save DX (contains drive number)
|
||||
#
|
||||
pushw %dx # Save
|
||||
xorw %dx,%dx # Port: COM1
|
||||
movb COMSPEED,%al # defined by Makefile
|
||||
movb $0x00,%ah # BIOS: Set COM Port
|
||||
int $0x14 # Parameters
|
||||
popw %dx # Restore
|
||||
/*
|
||||
* Initialize the serial port.
|
||||
* Must save DX (contains drive number)
|
||||
*/
|
||||
pushw %dx // Save
|
||||
xorw %dx,%dx // Port: COM1
|
||||
movb COMSPEED,%al // defined by Makefile
|
||||
movb $0x00,%ah // BIOS: Set COM Port
|
||||
int $0x14 // Parameters
|
||||
popw %dx // Restore
|
||||
#endif /* SIO */
|
||||
#
|
||||
# Check what flags were loaded with us, specifically, Use a predefined Drive.
|
||||
# If what the bios gives us is bad, use the '0' in the block instead, as well.
|
||||
#
|
||||
testb $0x20,_FLAGS(%bp) # Set number drive?
|
||||
jnz main.1 # Yes
|
||||
testb %dl,%dl # Drive number valid?
|
||||
js main.2 # Possibly (0x80 set)
|
||||
main.1: movb _SETDRV(%bp),%dl # Drive number to use
|
||||
#
|
||||
# Whatever we decided to use, now store it into the fake
|
||||
# partition entry that lives in the data space above us.
|
||||
#
|
||||
main.2: movb %dl,_FAKE(%bp) # Save drive number
|
||||
callw putn # To new line
|
||||
pushw %dx # Save drive number
|
||||
#
|
||||
# Start out with a pointer to the 4th byte of the first table entry
|
||||
# so that after 4 iterations it's beyond the end of the sector.
|
||||
# and beyond a 256 byte boundary and has overflowed 8 bits (see next comment).
|
||||
# (remember that the table starts 2 bytes earlier than you would expect
|
||||
# as the bootable flag is after it in the block)
|
||||
#
|
||||
movw $(partbl+0x4),%bx # Partition table (+4)
|
||||
xorw %dx,%dx # Item number
|
||||
#
|
||||
# Loop around on the partition table, printing values until we
|
||||
# pass a 256 byte boundary. The end of loop test is at main.5.
|
||||
#
|
||||
main.3: movb %ch,-0x4(%bx) # Zero active flag (ch == 0)
|
||||
btw %dx,_FLAGS(%bp) # Entry enabled?
|
||||
jnc main.5 # No
|
||||
#
|
||||
# If any of the entries in the table are
|
||||
# the same as the 'type' in the slice table entry,
|
||||
# then this is an empty or non bootable partition. Skip it.
|
||||
#
|
||||
movb (%bx),%al # Load type
|
||||
movw $tables,%di # Lookup tables
|
||||
movb $TBL0SZ,%cl # Number of entries
|
||||
repne # Exclude
|
||||
scasb # partition?
|
||||
je main.5 # Yes
|
||||
#
|
||||
# Now scan the table of known types
|
||||
#
|
||||
movb $TBL1SZ,%cl # Number of entries
|
||||
repne # Known
|
||||
scasb # type?
|
||||
jne main.4 # No
|
||||
#
|
||||
# If it matches get the matching element in the
|
||||
# next array. if it doesn't, we are already
|
||||
# pointing at its first element which points to a "?".
|
||||
#
|
||||
addw $TBL1SZ,%di # Adjust
|
||||
main.4: movb (%di),%cl # Partition
|
||||
addw %cx,%di # description
|
||||
callw putx # Display it
|
||||
main.5: incw %dx # Next item
|
||||
addb $0x10,%bl # Next entry
|
||||
jnc main.3 # Till done
|
||||
#
|
||||
# Passed a 256 byte boundary..
|
||||
# table is finished.
|
||||
# Add one to the drive number and check it is valid,
|
||||
#
|
||||
popw %ax # Drive number
|
||||
subb $0x80-0x1,%al # Does next
|
||||
cmpb NHRDRV,%al # drive exist? (from BIOS?)
|
||||
jb main.6 # Yes
|
||||
#
|
||||
# If not then if there is only one drive,
|
||||
# Don't display drive as an option.
|
||||
#
|
||||
decw %ax # Already drive 0?
|
||||
jz main.7 # Yes
|
||||
#
|
||||
# If it was illegal or we cycled through them,
|
||||
# then go back to drive 0.
|
||||
#
|
||||
xorb %al,%al # Drive 0
|
||||
#
|
||||
# Whatever drive we selected, make it an ascii digit and save it back
|
||||
# to the "next drive" location in the loaded block in case we
|
||||
# want to save it for next time.
|
||||
# This also is part of the printed drive string so add 0x80 to indicate
|
||||
# end of string.
|
||||
#
|
||||
main.6: addb $'0'|0x80,%al # Save next
|
||||
movb %al,_NXTDRV(%bp) # drive number
|
||||
movw $drive,%di # Display
|
||||
callw putx # item
|
||||
#
|
||||
# Now that we've printed the drive (if we needed to), display a prompt.
|
||||
# Get ready for the input by noting the time.
|
||||
#
|
||||
main.7: movw $prompt,%si # Display
|
||||
callw putstr # prompt
|
||||
movb _OPT(%bp),%dl # Display
|
||||
decw %si # default
|
||||
callw putkey # key
|
||||
/*
|
||||
* Check what flags were loaded with us, specifically, Use a predefined Drive.
|
||||
* If what the bios gives us is bad, use the '0' in the block instead, as well.
|
||||
*/
|
||||
testb $0x20,_FLAGS(%bp) // Set number drive?
|
||||
jnz main.1 // Yes
|
||||
testb %dl,%dl // Drive number valid?
|
||||
js main.2 // Possibly (0x80 set)
|
||||
main.1: movb _SETDRV(%bp),%dl // Drive number to use
|
||||
/*
|
||||
* Whatever we decided to use, now store it into the fake
|
||||
* partition entry that lives in the data space above us.
|
||||
*/
|
||||
main.2: movb %dl,_FAKE(%bp) // Save drive number
|
||||
callw putn // To new line
|
||||
pushw %dx // Save drive number
|
||||
/*
|
||||
* Start out with a pointer to the 4th byte of the first table entry
|
||||
* so that after 4 iterations it's beyond the end of the sector.
|
||||
* and beyond a 256 byte boundary and has overflowed 8 bits (see next comment).
|
||||
* (remember that the table starts 2 bytes earlier than you would expect
|
||||
* as the bootable flag is after it in the block)
|
||||
*/
|
||||
movw $(partbl+0x4),%bx // Partition table (+4)
|
||||
xorw %dx,%dx // Item number
|
||||
/*
|
||||
* Loop around on the partition table, printing values until we
|
||||
* pass a 256 byte boundary. The end of loop test is at main.5.
|
||||
*/
|
||||
main.3: movb %ch,-0x4(%bx) // Zero active flag (ch == 0)
|
||||
btw %dx,_FLAGS(%bp) // Entry enabled?
|
||||
jnc main.5 // No
|
||||
/*
|
||||
* If any of the entries in the table are
|
||||
* the same as the 'type' in the slice table entry,
|
||||
* then this is an empty or non bootable partition. Skip it.
|
||||
*/
|
||||
movb (%bx),%al // Load type
|
||||
movw $tables,%di // Lookup tables
|
||||
movb $TBL0SZ,%cl // Number of entries
|
||||
repne // Exclude
|
||||
scasb // partition?
|
||||
je main.5 // Yes
|
||||
/*
|
||||
* Now scan the table of known types
|
||||
*/
|
||||
movb $TBL1SZ,%cl // Number of entries
|
||||
repne // Known
|
||||
scasb // type?
|
||||
jne main.4 // No
|
||||
/*
|
||||
* If it matches get the matching element in the
|
||||
* next array. if it doesn't, we are already
|
||||
* pointing at its first element which points to a "?".
|
||||
*/
|
||||
addw $TBL1SZ,%di // Adjust
|
||||
main.4: movb (%di),%cl // Partition
|
||||
addw %cx,%di // description
|
||||
callw putx // Display it
|
||||
main.5: incw %dx // Next item
|
||||
addb $0x10,%bl // Next entry
|
||||
jnc main.3 // Till done
|
||||
/*
|
||||
* Passed a 256 byte boundary..
|
||||
* table is finished.
|
||||
* Add one to the drive number and check it is valid,
|
||||
*/
|
||||
popw %ax // Drive number
|
||||
subb $0x80-0x1,%al // Does next
|
||||
cmpb NHRDRV,%al // drive exist? (from BIOS?)
|
||||
jb main.6 // Yes
|
||||
/*
|
||||
* If not then if there is only one drive,
|
||||
* Don't display drive as an option.
|
||||
*/
|
||||
decw %ax // Already drive 0?
|
||||
jz main.7 // Yes
|
||||
/*
|
||||
* If it was illegal or we cycled through them,
|
||||
* then go back to drive 0.
|
||||
*/
|
||||
xorb %al,%al // Drive 0
|
||||
/*
|
||||
* Whatever drive we selected, make it an ascii digit and save it back
|
||||
* to the "next drive" location in the loaded block in case we
|
||||
* want to save it for next time.
|
||||
* This also is part of the printed drive string so add 0x80 to indicate
|
||||
* end of string.
|
||||
*/
|
||||
main.6: addb $'0'|0x80,%al // Save next
|
||||
movb %al,_NXTDRV(%bp) // drive number
|
||||
movw $drive,%di // Display
|
||||
callw putx // item
|
||||
/*
|
||||
* Now that we've printed the drive (if we needed to), display a prompt.
|
||||
* Get ready for the input by noting the time.
|
||||
*/
|
||||
main.7: movw $prompt,%si // Display
|
||||
callw putstr // prompt
|
||||
movb _OPT(%bp),%dl // Display
|
||||
decw %si // default
|
||||
callw putkey // key
|
||||
main.7_1:
|
||||
xorb %ah,%ah # BIOS: Get
|
||||
int $0x1a # system time
|
||||
xorb %ah,%ah // BIOS: Get
|
||||
int $0x1a // system time
|
||||
#ifndef SIO
|
||||
movw %dx,%di # Ticks when
|
||||
addw _TICKS(%bp),%di # timeout
|
||||
movw %dx,%di // Ticks when
|
||||
addw _TICKS(%bp),%di // timeout
|
||||
#else /* SIO */
|
||||
movw %dx,%si # Ticks when
|
||||
addw _TICKS(%bp),%si # timeout
|
||||
movw %dx,%si // Ticks when
|
||||
addw _TICKS(%bp),%si // timeout
|
||||
#endif /* SIO */
|
||||
#
|
||||
# Busy loop, looking for keystrokes but
|
||||
# keeping one eye on the time.
|
||||
#
|
||||
/*
|
||||
* Busy loop, looking for keystrokes but
|
||||
* keeping one eye on the time.
|
||||
*/
|
||||
main.8:
|
||||
#ifndef SIO
|
||||
movb $0x1,%ah # BIOS: Check
|
||||
int $0x16 # for keypress
|
||||
jnz main.11 # Have one
|
||||
movb $0x1,%ah // BIOS: Check
|
||||
int $0x16 // for keypress
|
||||
jnz main.11 // Have one
|
||||
#else /* SIO */
|
||||
xorw %dx,%dx # Use COM1
|
||||
movb $0x03,%ah # BIOS: Read COM
|
||||
int $0x14 # Status
|
||||
testb $0x01,%ah # Check line status
|
||||
jnz main.11 # (bit 1 indicates input)
|
||||
xorw %dx,%dx // Use COM1
|
||||
movb $0x03,%ah // BIOS: Read COM
|
||||
int $0x14 // Status
|
||||
testb $0x01,%ah // Check line status
|
||||
jnz main.11 // (bit 1 indicates input)
|
||||
#endif /* SIO */
|
||||
xorb %ah,%ah # BIOS: Get
|
||||
int $0x1a # system time
|
||||
xorb %ah,%ah // BIOS: Get
|
||||
int $0x1a // system time
|
||||
#ifndef SIO
|
||||
cmpw %di,%dx # Timeout?
|
||||
cmpw %di,%dx // Timeout?
|
||||
#else /* SIO */
|
||||
cmpw %si,%dx # Timeout?
|
||||
cmpw %si,%dx // Timeout?
|
||||
#endif /* SIO */
|
||||
jb main.8 # No
|
||||
#
|
||||
# If timed out or defaulting, come here.
|
||||
#
|
||||
main.9: movb _OPT(%bp),%al # Load default
|
||||
jmp main.12 # Join common code
|
||||
#
|
||||
# User's last try was bad, beep in displeasure.
|
||||
# Since nothing was printed, just continue on as if the user
|
||||
# hadn't done anything. This gives the effect of the user getting a beep
|
||||
# for all bad keystrokes but no action until either the timeout
|
||||
# occurs or the user hits a good key.
|
||||
#
|
||||
main.10: movb $ASCII_BEL,%al # Signal
|
||||
callw putchr # error
|
||||
jb main.8 // No
|
||||
/*
|
||||
* If timed out or defaulting, come here.
|
||||
*/
|
||||
main.9: movb _OPT(%bp),%al // Load default
|
||||
jmp main.12 // Join common code
|
||||
/*
|
||||
* User's last try was bad, beep in displeasure.
|
||||
* Since nothing was printed, just continue on as if the user
|
||||
* hadn't done anything. This gives the effect of the user getting a beep
|
||||
* for all bad keystrokes but no action until either the timeout
|
||||
* occurs or the user hits a good key.
|
||||
*/
|
||||
main.10: movb $ASCII_BEL,%al // Signal
|
||||
callw putchr // error
|
||||
#ifdef SIO
|
||||
jmp main.7_1 # Go back
|
||||
jmp main.7_1 // Go back
|
||||
#endif /* SIO */
|
||||
#
|
||||
# Get the keystroke.
|
||||
#
|
||||
/*
|
||||
* Get the keystroke.
|
||||
*/
|
||||
main.11:
|
||||
#ifndef SIO
|
||||
xorb %ah,%ah # BIOS: Get
|
||||
int $0x16 # keypress
|
||||
movb %ah,%al # Scan code
|
||||
xorb %ah,%ah // BIOS: Get
|
||||
int $0x16 // keypress
|
||||
movb %ah,%al // Scan code
|
||||
#else /* SIO */
|
||||
movb $0x02,%ah # BIOS: Receive
|
||||
int $0x14 # COM Byte
|
||||
movb $0x02,%ah // BIOS: Receive
|
||||
int $0x14 // COM Byte
|
||||
#endif /* SIO */
|
||||
#
|
||||
# If it's CR act as if timed out.
|
||||
#
|
||||
/*
|
||||
* If it's CR act as if timed out.
|
||||
*/
|
||||
#ifndef SIO
|
||||
cmpb $KEY_ENTER,%al # Enter pressed?
|
||||
cmpb $KEY_ENTER,%al // Enter pressed?
|
||||
#else /* SIO */
|
||||
cmpb $ASCII_CR,%al # Enter pressed?
|
||||
cmpb $ASCII_CR,%al // Enter pressed?
|
||||
#endif /* SIO */
|
||||
je main.9 # Yes
|
||||
#
|
||||
# Otherwise check if legal
|
||||
# If not ask again.
|
||||
#
|
||||
je main.9 // Yes
|
||||
/*
|
||||
* Otherwise check if legal
|
||||
* If not ask again.
|
||||
*/
|
||||
#ifndef SIO
|
||||
subb $KEY_F1,%al # Less F1 scan code
|
||||
cmpb $0x4,%al # F1..F5?
|
||||
jna main.12 # Yes
|
||||
subb $(KEY_1 - KEY_F1),%al # Less #1 scan code
|
||||
subb $KEY_F1,%al // Less F1 scan code
|
||||
cmpb $0x4,%al // F1..F5?
|
||||
jna main.12 // Yes
|
||||
subb $(KEY_1 - KEY_F1),%al // Less #1 scan code
|
||||
#else /* SIO */
|
||||
subb $'1',%al # Less '1' ascii character
|
||||
subb $'1',%al // Less '1' ascii character
|
||||
#endif /* SIO */
|
||||
cmpb $0x4,%al # #1..#5?
|
||||
ja main.10 # No
|
||||
#
|
||||
# We have a selection.
|
||||
# but if it's a bad selection go back to complain.
|
||||
# The bits in MNUOPT were set when the options were printed.
|
||||
# Anything not printed is not an option.
|
||||
#
|
||||
main.12: cbtw # Option
|
||||
btw %ax,_MNUOPT(%bp) # enabled?
|
||||
jnc main.10 # No
|
||||
#
|
||||
# Save the info in the original tables
|
||||
# for rewriting to the disk.
|
||||
#
|
||||
movb %al,_OPT(%bp) # Save option
|
||||
movw $FAKE,%si # Partition for write
|
||||
movb (%si),%dl # Drive number
|
||||
movw %si,%bx # Partition for read
|
||||
cmpb $0x4,%al # F5/#5 pressed?
|
||||
pushf # Save
|
||||
je main.13 # Yes
|
||||
shlb $0x4,%al # Point to
|
||||
addw $partbl,%ax # selected
|
||||
xchgw %bx,%ax # partition
|
||||
movb $0x80,(%bx) # Flag active
|
||||
#
|
||||
# If not asked to do a write-back (flags 0x40) don't do one.
|
||||
#
|
||||
main.13: pushw %bx # Save
|
||||
testb $0x40,_FLAGS(%bp) # No updates?
|
||||
jnz main.14 # Yes
|
||||
movw $start,%bx # Data to write
|
||||
movb $0x3,%ah # Write sector
|
||||
callw intx13 # to disk
|
||||
main.14: popw %si # Restore
|
||||
popf # Restore
|
||||
#
|
||||
# If going to next drive, replace drive with selected one.
|
||||
# Remember to un-ascii it. Hey 0x80 is already set, cool!
|
||||
#
|
||||
jne main.15 # If not F5/#5
|
||||
movb _NXTDRV(%bp),%dl # Next drive
|
||||
subb $'0',%dl # number
|
||||
#
|
||||
# load selected bootsector to the LOAD location in RAM.
|
||||
# If it fails to read or isn't marked bootable, treat it
|
||||
# as a bad selection.
|
||||
# XXX what does %si carry?
|
||||
#
|
||||
main.15: movw $LOAD,%bx # Address for read
|
||||
movb $0x2,%ah # Read sector
|
||||
callw intx13 # from disk
|
||||
jc main.10 # If error
|
||||
cmpw $MAGIC,0x1fe(%bx) # Bootable?
|
||||
jne main.10 # No
|
||||
pushw %si # Save
|
||||
movw $crlf,%si # Leave some
|
||||
callw puts # space
|
||||
popw %si # Restore
|
||||
jmp *%bx # Invoke bootstrap
|
||||
cmpb $0x4,%al // #1..#5?
|
||||
ja main.10 // No
|
||||
/*
|
||||
* We have a selection.
|
||||
* but if it's a bad selection go back to complain.
|
||||
* The bits in MNUOPT were set when the options were printed.
|
||||
* Anything not printed is not an option.
|
||||
*/
|
||||
main.12: cbtw // Option
|
||||
btw %ax,_MNUOPT(%bp) // enabled?
|
||||
jnc main.10 // No
|
||||
/*
|
||||
* Save the info in the original tables
|
||||
* for rewriting to the disk.
|
||||
*/
|
||||
movb %al,_OPT(%bp) // Save option
|
||||
movw $FAKE,%si // Partition for write
|
||||
movb (%si),%dl // Drive number
|
||||
movw %si,%bx // Partition for read
|
||||
cmpb $0x4,%al // F5/#5 pressed?
|
||||
pushf // Save
|
||||
je main.13 // Yes
|
||||
shlb $0x4,%al // Point to
|
||||
addw $partbl,%ax // selected
|
||||
xchgw %bx,%ax // partition
|
||||
movb $0x80,(%bx) // Flag active
|
||||
/*
|
||||
* If not asked to do a write-back (flags 0x40) don't do one.
|
||||
*/
|
||||
main.13: pushw %bx // Save
|
||||
testb $0x40,_FLAGS(%bp) // No updates?
|
||||
jnz main.14 // Yes
|
||||
movw $start,%bx // Data to write
|
||||
movb $0x3,%ah // Write sector
|
||||
callw intx13 // to disk
|
||||
main.14: popw %si // Restore
|
||||
popf // Restore
|
||||
/*
|
||||
* If going to next drive, replace drive with selected one.
|
||||
* Remember to un-ascii it. Hey 0x80 is already set, cool!
|
||||
*/
|
||||
jne main.15 // If not F5/#5
|
||||
movb _NXTDRV(%bp),%dl // Next drive
|
||||
subb $'0',%dl // number
|
||||
/*
|
||||
* load selected bootsector to the LOAD location in RAM.
|
||||
* If it fails to read or isn't marked bootable, treat it
|
||||
* as a bad selection.
|
||||
* XXX what does %si carry?
|
||||
*/
|
||||
main.15: movw $LOAD,%bx // Address for read
|
||||
movb $0x2,%ah // Read sector
|
||||
callw intx13 // from disk
|
||||
jc main.10 // If error
|
||||
cmpw $MAGIC,0x1fe(%bx) // Bootable?
|
||||
jne main.10 // No
|
||||
pushw %si // Save
|
||||
movw $crlf,%si // Leave some
|
||||
callw puts // space
|
||||
popw %si // Restore
|
||||
jmp *%bx // Invoke bootstrap
|
||||
|
||||
#
|
||||
# Display routines
|
||||
#
|
||||
/*
|
||||
* Display routines
|
||||
*/
|
||||
putkey:
|
||||
#ifndef SIO
|
||||
movb $'F',%al # Display
|
||||
callw putchr # 'F'
|
||||
movb $'F',%al // Display
|
||||
callw putchr // 'F'
|
||||
#endif /* SIO */
|
||||
movb $'1',%al # Prepare
|
||||
addb %dl,%al # digit
|
||||
jmp putstr.1 # Display the rest
|
||||
movb $'1',%al // Prepare
|
||||
addb %dl,%al // digit
|
||||
jmp putstr.1 // Display the rest
|
||||
|
||||
#
|
||||
# Display the option and note that it is a valid option.
|
||||
# That last point is a bit tricky..
|
||||
#
|
||||
putx: btsw %dx,_MNUOPT(%bp) # Enable menu option
|
||||
movw $item,%si # Display
|
||||
callw putkey # key
|
||||
movw %di,%si # Display the rest
|
||||
/*
|
||||
* Display the option and note that it is a valid option.
|
||||
* That last point is a bit tricky..
|
||||
*/
|
||||
putx: btsw %dx,_MNUOPT(%bp) // Enable menu option
|
||||
movw $item,%si // Display
|
||||
callw putkey // key
|
||||
movw %di,%si // Display the rest
|
||||
|
||||
puts: callw putstr # Display string
|
||||
puts: callw putstr // Display string
|
||||
|
||||
putn: movw $crlf,%si # To next line
|
||||
putn: movw $crlf,%si // To next line
|
||||
|
||||
putstr: lodsb # Get byte
|
||||
testb $0x80,%al # End of string?
|
||||
jnz putstr.2 # Yes
|
||||
putstr.1: callw putchr # Display char
|
||||
jmp putstr # Continue
|
||||
putstr.2: andb $~0x80,%al # Clear MSB
|
||||
putstr: lodsb // Get byte
|
||||
testb $0x80,%al // End of string?
|
||||
jnz putstr.2 // Yes
|
||||
putstr.1: callw putchr // Display char
|
||||
jmp putstr // Continue
|
||||
putstr.2: andb $~0x80,%al // Clear MSB
|
||||
|
||||
putchr:
|
||||
#ifndef SIO
|
||||
pushw %bx # Save
|
||||
movw $0x7,%bx # Page:attribute
|
||||
movb $0xe,%ah # BIOS: Display
|
||||
int $0x10 # character
|
||||
popw %bx # Restore
|
||||
pushw %bx // Save
|
||||
movw $0x7,%bx // Page:attribute
|
||||
movb $0xe,%ah // BIOS: Display
|
||||
int $0x10 // character
|
||||
popw %bx // Restore
|
||||
#else /* SIO */
|
||||
pushw %dx # Save
|
||||
xorw %dx,%dx # Use COM1
|
||||
xorw %cx,%cx # No timeout
|
||||
movb $0x01,%ah # BIOS: Send
|
||||
int $0x14 # Character
|
||||
popw %dx # Restore
|
||||
pushw %dx // Save
|
||||
xorw %dx,%dx // Use COM1
|
||||
xorw %cx,%cx // No timeout
|
||||
movb $0x01,%ah // BIOS: Send
|
||||
int $0x14 // Character
|
||||
popw %dx // Restore
|
||||
#endif /* SIO */
|
||||
retw # To caller
|
||||
retw // To caller
|
||||
|
||||
# One-sector disk I/O routine
|
||||
/* One-sector disk I/O routine */
|
||||
|
||||
intx13: movb 0x1(%si),%dh # Load head
|
||||
movw 0x2(%si),%cx # Load cylinder:sector
|
||||
movb $0x1,%al # Sector count
|
||||
pushw %si # Save
|
||||
movw %sp,%di # Save
|
||||
testb $0x80,_FLAGS(%bp) # Use packet interface?
|
||||
jz intx13.1 # No
|
||||
pushl $0x0 # Set the
|
||||
pushl 0x8(%si) # LBA address
|
||||
pushw %es # Set the transfer
|
||||
pushw %bx # buffer address
|
||||
push $0x1 # Block count
|
||||
push $0x10 # Packet size
|
||||
movw %sp,%si # Packet pointer
|
||||
decw %ax # Verify off
|
||||
orb $0x40,%ah # Use disk packet
|
||||
intx13.1: int $0x13 # BIOS: Disk I/O
|
||||
movw %di,%sp # Restore
|
||||
popw %si # Restore
|
||||
retw # To caller
|
||||
intx13: movb 0x1(%si),%dh // Load head
|
||||
movw 0x2(%si),%cx // Load cylinder:sector
|
||||
movb $0x1,%al // Sector count
|
||||
pushw %si // Save
|
||||
movw %sp,%di // Save
|
||||
testb $0x80,_FLAGS(%bp) // Use packet interface?
|
||||
jz intx13.1 // No
|
||||
pushl $0x0 // Set the
|
||||
pushl 0x8(%si) // LBA address
|
||||
pushw %es // Set the transfer
|
||||
pushw %bx // buffer address
|
||||
push $0x1 // Block count
|
||||
push $0x10 // Packet size
|
||||
movw %sp,%si // Packet pointer
|
||||
decw %ax // Verify off
|
||||
orb $0x40,%ah // Use disk packet
|
||||
intx13.1: int $0x13 // BIOS: Disk I/O
|
||||
movw %di,%sp // Restore
|
||||
popw %si // Restore
|
||||
retw // To caller
|
||||
|
||||
# Menu strings
|
||||
/* Menu strings */
|
||||
|
||||
#ifndef SIO
|
||||
item: .ascii " "; .byte ' '|0x80
|
||||
@ -435,38 +435,38 @@ prompt: .ascii "\nDef:"; .byte ' '|0x80
|
||||
#endif /* SIO */
|
||||
crlf: .ascii "\r"; .byte '\n'|0x80
|
||||
|
||||
# Partition type tables
|
||||
/* Partition type tables */
|
||||
|
||||
tables:
|
||||
#
|
||||
# These entries identify invalid or NON BOOT types and partitions.
|
||||
#
|
||||
/*
|
||||
* These entries identify invalid or NON BOOT types and partitions.
|
||||
*/
|
||||
.byte 0x0, 0x5, 0xf
|
||||
#
|
||||
# These values indicate bootable types we know the names of
|
||||
#
|
||||
/*
|
||||
* These values indicate bootable types we know the names of
|
||||
*/
|
||||
.byte 0x1, 0x4, 0x6, 0xb, 0xc, 0xe, 0x83
|
||||
.byte 0x9f, 0xa5, 0xa6, 0xa9
|
||||
#
|
||||
# These are offsets that match the known names above and point to the strings
|
||||
# that will be printed.
|
||||
#
|
||||
.byte os_misc-. # Unknown
|
||||
.byte os_dos-. # DOS
|
||||
.byte os_dos-. # DOS
|
||||
.byte os_dos-. # DOS
|
||||
.byte os_dos-. # Windows
|
||||
.byte os_dos-. # Windows
|
||||
.byte os_dos-. # Windows
|
||||
.byte os_linux-. # Linux
|
||||
.byte os_bsd-. # BSD/OS
|
||||
.byte os_freebsd-. # FreeBSD
|
||||
.byte os_bsd-. # OpenBSD
|
||||
.byte os_bsd-. # NetBSD
|
||||
#
|
||||
# And here are the strings themselves. 0x80 or'd into a byte indicates
|
||||
# the end of the string. (not so great for Russians but...)
|
||||
#
|
||||
/*
|
||||
* These are offsets that match the known names above and point to the strings
|
||||
* that will be printed.
|
||||
*/
|
||||
.byte os_misc-. // Unknown
|
||||
.byte os_dos-. // DOS
|
||||
.byte os_dos-. // DOS
|
||||
.byte os_dos-. // DOS
|
||||
.byte os_dos-. // Windows
|
||||
.byte os_dos-. // Windows
|
||||
.byte os_dos-. // Windows
|
||||
.byte os_linux-. // Linux
|
||||
.byte os_bsd-. // BSD/OS
|
||||
.byte os_freebsd-. // FreeBSD
|
||||
.byte os_bsd-. // OpenBSD
|
||||
.byte os_bsd-. // NetBSD
|
||||
/*
|
||||
* And here are the strings themselves. 0x80 or'd into a byte indicates
|
||||
* the end of the string. (not so great for Russians but...)
|
||||
*/
|
||||
os_misc: .ascii "?"; .byte '?'|0x80
|
||||
os_dos: .ascii "DO"; .byte 'S'|0x80
|
||||
os_linux: .ascii "Linu"; .byte 'x'|0x80
|
||||
@ -475,22 +475,22 @@ os_bsd: .ascii "BS"; .byte 'D'|0x80
|
||||
|
||||
.org PRT_OFF-0xe,0x90
|
||||
|
||||
.word B0MAGIC # Magic number
|
||||
.word B0MAGIC // Magic number
|
||||
|
||||
#
|
||||
# These values are sometimes changed before writing back to the drive
|
||||
# Be especially careful that nxtdrv: must come after drive:, as it
|
||||
# is part of the same string.
|
||||
#
|
||||
/*
|
||||
* These values are sometimes changed before writing back to the drive
|
||||
* Be especially careful that nxtdrv: must come after drive:, as it
|
||||
* is part of the same string.
|
||||
*/
|
||||
drive: .ascii "Drive "
|
||||
nxtdrv: .byte 0x0 # Next drive number
|
||||
opt: .byte 0x0 # Option
|
||||
setdrv: .byte 0x80 # Drive to force
|
||||
flags: .byte FLAGS # Flags
|
||||
ticks: .word TICKS # Delay
|
||||
nxtdrv: .byte 0x0 // Next drive number
|
||||
opt: .byte 0x0 // Option
|
||||
setdrv: .byte 0x80 // Drive to force
|
||||
flags: .byte FLAGS // Flags
|
||||
ticks: .word TICKS // Delay
|
||||
|
||||
#
|
||||
# here is the 64 byte partition table that fdisk would fiddle with.
|
||||
#
|
||||
partbl: .fill 0x40,0x1,0x0 # Partition table
|
||||
.word MAGIC # Magic number
|
||||
/*
|
||||
* here is the 64 byte partition table that fdisk would fiddle with.
|
||||
*/
|
||||
partbl: .fill 0x40,0x1,0x0 // Partition table
|
||||
.word MAGIC // Magic number
|
||||
|
||||
Loading…
Reference in New Issue
Block a user