Use C (and CPP) style comments for assembler-with-cpp sources,
for lines that start with a comment.
This commit is contained in:
Ruslan Ermilov
parent
4b35719adf
commit
d1974eb1c5
@ -1,23 +1,23 @@
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#
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# Copyright (c) 1998 Robert Nordier
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# All rights reserved.
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#
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# Redistribution and use in source and binary forms are freely
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# permitted provided that the above copyright notice and this
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# paragraph and the following disclaimer are duplicated in all
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# such forms.
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#
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# This software is provided "AS IS" and without any express or
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# implied warranties, including, without limitation, the implied
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# warranties of merchantability and fitness for a particular
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# purpose.
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#
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/*
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* Copyright (c) 1998 Robert Nordier
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms are freely
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* permitted provided that the above copyright notice and this
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* paragraph and the following disclaimer are duplicated in all
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* such forms.
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*
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* This software is provided "AS IS" and without any express or
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* implied warranties, including, without limitation, the implied
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* warranties of merchantability and fitness for a particular
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* purpose.
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*
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* $FreeBSD$
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*/
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# $FreeBSD$
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#
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# Memory layout.
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#
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/*
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* Memory layout.
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*/
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.set MEM_BTX,0x1000 # Start of BTX memory
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.set MEM_ESP0,0x1800 # Supervisor stack
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.set MEM_BUF,0x1800 # Scratch buffer
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@ -29,14 +29,14 @@
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.set MEM_TBL,0x5000 # Page tables
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.set MEM_ORG,0x9000 # BTX code
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.set MEM_USR,0xa000 # Start of user memory
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#
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# Paging control.
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#
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/*
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* Paging control.
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*/
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.set PAG_SIZ,0x1000 # Page size
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.set PAG_CNT,0x1000 # Pages to map
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#
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# Segment selectors.
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#
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/*
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* Segment selectors.
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*/
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.set SEL_SCODE,0x8 # Supervisor code
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.set SEL_SDATA,0x10 # Supervisor data
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.set SEL_RCODE,0x18 # Real mode code
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@ -44,61 +44,61 @@
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.set SEL_UCODE,0x28|3 # User code
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.set SEL_UDATA,0x30|3 # User data
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.set SEL_TSS,0x38 # TSS
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#
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# Task state segment fields.
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#
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/*
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* Task state segment fields.
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*/
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.set TSS_ESP0,0x4 # PL 0 ESP
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.set TSS_SS0,0x8 # PL 0 SS
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.set TSS_ESP1,0xc # PL 1 ESP
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.set TSS_MAP,0x66 # I/O bit map base
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#
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# System calls.
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#
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/*
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* System calls.
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*/
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.set SYS_EXIT,0x0 # Exit
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.set SYS_EXEC,0x1 # Exec
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#
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# V86 constants.
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#
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/*
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* V86 constants.
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*/
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.set V86_FLG,0x208eff # V86 flag mask
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.set V86_STK,0x400 # V86 stack allowance
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#
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# Dump format control bytes.
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#
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/*
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* Dump format control bytes.
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*/
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.set DMP_X16,0x1 # Word
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.set DMP_X32,0x2 # Long
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.set DMP_MEM,0x4 # Memory
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.set DMP_EOL,0x8 # End of line
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#
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# Screen defaults and assumptions.
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#
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/*
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* Screen defaults and assumptions.
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*/
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.set SCR_MAT,0x7 # Mode/attribute
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.set SCR_COL,0x50 # Columns per row
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.set SCR_ROW,0x19 # Rows per screen
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#
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# BIOS Data Area locations.
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#
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/*
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* BIOS Data Area locations.
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*/
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.set BDA_MEM,0x413 # Free memory
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.set BDA_KEYFLAGS,0x417 # Keyboard shift-state flags
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.set BDA_SCR,0x449 # Video mode
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.set BDA_POS,0x450 # Cursor position
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.set BDA_BOOT,0x472 # Boot howto flag
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#
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# Derivations, for brevity.
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#
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/*
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* Derivations, for brevity.
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*/
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.set _ESP0H,MEM_ESP0>>0x8 # Byte 1 of ESP0
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.set _ESP1H,MEM_ESP1>>0x8 # Byte 1 of ESP1
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.set _TSSIO,MEM_MAP-MEM_TSS # TSS I/O base
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.set _TSSLM,MEM_DIR-MEM_TSS-1 # TSS limit
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.set _IDTLM,MEM_TSS-MEM_IDT-1 # IDT limit
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#
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# Code segment.
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#
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/*
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* Code segment.
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*/
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.globl start
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.code16
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start: # Start of code
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#
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# BTX header.
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#
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/*
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* BTX header.
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*/
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btx_hdr: .byte 0xeb # Machine ID
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.byte 0xe # Header size
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.ascii "BTX" # Magic
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@ -108,9 +108,9 @@ btx_hdr: .byte 0xeb # Machine ID
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.word PAG_CNT-MEM_ORG>>0xc # Paging control
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.word break-start # Text size
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.long 0x0 # Entry address
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#
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# Initialization routine.
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#
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/*
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* Initialization routine.
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*/
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init: cli # Disable interrupts
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xor %ax,%ax # Zero/segment
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mov %ax,%ss # Set up
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@ -119,18 +119,18 @@ init: cli # Disable interrupts
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mov %ax,%ds # data
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pushl $0x2 # Clear
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popfl # flags
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#
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# Initialize memory.
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#
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/*
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* Initialize memory.
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*/
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mov $MEM_IDT,%di # Memory to initialize
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mov $(MEM_ORG-MEM_IDT)/2,%cx # Words to zero
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push %di # Save
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rep # Zero-fill
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stosw # memory
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pop %di # Restore
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#
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# Create IDT.
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#
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/*
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* Create IDT.
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*/
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mov $idtctl,%si # Control string
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init.1: lodsb # Get entry
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cbw # count
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@ -151,17 +151,17 @@ init.2: shr %bx # Handle this int?
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init.3: lea 0x8(%di),%di # Next entry
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loop init.2 # Till set done
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jmp init.1 # Continue
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#
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# Initialize TSS.
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#
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/*
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* Initialize TSS.
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*/
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init.4: movb $_ESP0H,TSS_ESP0+1(%di) # Set ESP0
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movb $SEL_SDATA,TSS_SS0(%di) # Set SS0
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movb $_ESP1H,TSS_ESP1+1(%di) # Set ESP1
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movb $_TSSIO,TSS_MAP(%di) # Set I/O bit map base
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#ifdef PAGING
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#
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# Create page directory.
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#
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/*
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* Create page directory.
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*/
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xor %edx,%edx # Page
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mov $PAG_SIZ>>0x8,%dh # size
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xor %eax,%eax # Zero
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@ -171,9 +171,9 @@ init.4: movb $_ESP0H,TSS_ESP0+1(%di) # Set ESP0
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init.5: stosl # Write entry
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add %dx,%ax # To next
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loop init.5 # Till done
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#
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# Create page tables.
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#
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/*
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* Create page tables.
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*/
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mov $MEM_TBL,%di # Page table
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mov $PAG_CNT>>0x8,%ch # Entries
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xor %ax,%ax # Start address
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@ -192,9 +192,9 @@ init.7: stosl # Set entry
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add %edx,%eax # Next address
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loop init.6 # Till done
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#endif
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#
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# Bring up the system.
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#
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/*
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* Bring up the system.
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*/
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mov $0x2820,%bx # Set protected mode
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callw setpic # IRQ offsets
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lidt idtdesc # Set IDT
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@ -210,15 +210,15 @@ init.7: stosl # Set entry
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#else
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or $0x01,%eax # mode
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#endif
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mov %eax,%cr0 #
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mov %eax,%cr0 #
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ljmp $SEL_SCODE,$init.8 # To 32-bit code
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.code32
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init.8: xorl %ecx,%ecx # Zero
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movb $SEL_SDATA,%cl # To 32-bit
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movw %cx,%ss # stack
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#
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# Launch user task.
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#
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/*
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* Launch user task.
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*/
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movb $SEL_TSS,%cl # Set task
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ltr %cx # register
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movl $MEM_USR,%edx # User base address
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@ -249,26 +249,26 @@ init.9: push $0x0 # general
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popl %fs # segment
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popl %gs # registers
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iret # To user mode
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#
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# Exit routine.
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#
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/*
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* Exit routine.
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*/
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exit: cli # Disable interrupts
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movl $MEM_ESP0,%esp # Clear stack
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#
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# Turn off paging.
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#
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/*
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* Turn off paging.
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*/
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movl %cr0,%eax # Get CR0
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andl $~0x80000000,%eax # Disable
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movl %eax,%cr0 # paging
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xorl %ecx,%ecx # Zero
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movl %ecx,%cr3 # Flush TLB
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#
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# Restore the GDT in case we caught a kernel trap.
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#
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/*
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* Restore the GDT in case we caught a kernel trap.
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*/
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lgdt gdtdesc # Set GDT
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#
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# To 16 bits.
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#
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/*
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* To 16 bits.
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*/
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ljmpw $SEL_RCODE,$exit.1 # Reload CS
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.code16
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exit.1: mov $SEL_RDATA,%cl # 16-bit selector
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@ -277,9 +277,9 @@ exit.1: mov $SEL_RDATA,%cl # 16-bit selector
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mov %cx,%es # remaining
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mov %cx,%fs # segment
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mov %cx,%gs # registers
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#
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# To real-address mode.
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#
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/*
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* To real-address mode.
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*/
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dec %ax # Switch to
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mov %eax,%cr0 # real mode
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ljmp $0x0,$exit.2 # Reload CS
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@ -289,17 +289,17 @@ exit.2: xor %ax,%ax # Real mode segment
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mov $0x7008,%bx # Set real mode
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callw setpic # IRQ offsets
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lidt ivtdesc # Set IVT
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#
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# Reboot or await reset.
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#
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/*
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* Reboot or await reset.
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*/
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sti # Enable interrupts
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testb $0x1,btx_hdr+0x7 # Reboot?
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exit.3: jz exit.3 # No
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movw $0x1234, BDA_BOOT # Do a warm boot
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ljmp $0xf000,$0xfff0 # reboot the machine
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#
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# Set IRQ offsets by reprogramming 8259A PICs.
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#
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/*
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* Set IRQ offsets by reprogramming 8259A PICs.
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*/
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setpic: in $0x21,%al # Save master
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push %ax # IMR
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in $0xa1,%al # Save slave
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@ -324,13 +324,13 @@ setpic: in $0x21,%al # Save master
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outb %al,$0x21 # IMR
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retw # To caller
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.code32
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#
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# Initiate return from V86 mode to user mode.
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#
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/*
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* Initiate return from V86 mode to user mode.
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*/
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inthlt: hlt # To supervisor mode
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#
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# Exception jump table.
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#
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/*
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* Exception jump table.
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*/
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intx00: push $0x0 # Int 0x0: #DE
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jmp ex_noc # Divide error
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push $0x1 # Int 0x1: #DB
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@ -359,20 +359,20 @@ intx00: push $0x0 # Int 0x0: #DE
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jmp except # Page fault
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intx10: push $0x10 # Int 0x10: #MF
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jmp ex_noc # Floating-point error
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#
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# Handle #GP exception.
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#
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/*
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* Handle #GP exception.
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*/
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ex_v86: testb $0x2,0x12(%esp,1) # V86 mode?
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jz except # No
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jmp v86mon # To monitor
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#
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# Save a zero error code.
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#
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/*
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* Save a zero error code.
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*/
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ex_noc: pushl (%esp,1) # Duplicate int no
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movb $0x0,0x4(%esp,1) # Fake error code
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#
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# Handle exception.
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#
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/*
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* Handle exception.
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*/
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except: cld # String ops inc
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pushl %ds # Save
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pushl %es # most
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@ -418,9 +418,9 @@ except.2: push $SEL_SDATA # Set up
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except.2a: jmp exit # Exit
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except.3: leal 0x8(%esp,1),%esp # Discard err, int no
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iret # From interrupt
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#
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# Return to user mode from V86 mode.
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#
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/*
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* Return to user mode from V86 mode.
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*/
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intrtn: cld # String ops inc
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pushl %ds # Address
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popl %es # data
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@ -460,9 +460,9 @@ intrtn.2: movl %edx,%esi # Segment registers
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popl %fs # segment
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popl %gs # registers
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iret # To user mode
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#
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# V86 monitor.
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#
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/*
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* V86 monitor.
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*/
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v86mon: cld # String ops inc
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pushl $SEL_SDATA # Set up for
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popl %ds # flat addressing
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@ -526,69 +526,69 @@ v86mon.7: subl %edi,%esi # From linear
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popa # Restore
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leal 0x8(%esp,1),%esp # Discard int no, error
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iret # To V86 mode
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#
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# Emulate MOV EAX,CR0.
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#
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/*
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* Emulate MOV EAX,CR0.
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*/
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v86mov: movl %cr0,%eax # CR0 to
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movl %eax,0x1c(%ebp) # saved EAX
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incl %esi # Adjust IP
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#
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# Return from emulating a 0x0f prefixed instruction
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#
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/*
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* Return from emulating a 0x0f prefixed instruction
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*/
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v86preret: incl %esi # Adjust IP
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jmp v86mon.7 # Finish up
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#
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# Emulate WBINVD
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#
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/*
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* Emulate WBINVD
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*/
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v86wbinvd: wbinvd # Write back and invalidate
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# cache
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jmp v86preret # Finish up
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#
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# Emulate WRMSR
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#
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/*
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* Emulate WRMSR
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*/
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v86wrmsr: movl 0x18(%ebp),%ecx # Get user's %ecx (MSR to write)
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movl 0x14(%ebp),%edx # Load the value
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movl 0x1c(%ebp),%eax # to write
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wrmsr # Write MSR
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jmp v86preret # Finish up
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#
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# Emulate RDMSR
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#
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/*
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* Emulate RDMSR
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*/
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v86rdmsr: movl 0x18(%ebp),%ecx # MSR to read
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rdmsr # Read the MSR
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movl %eax,0x1c(%ebp) # Return the value of
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movl %edx,0x14(%ebp) # the MSR to the user
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jmp v86preret # Finish up
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||||
#
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# Emulate CLI.
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#
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/*
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* Emulate CLI.
|
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*/
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v86cli: andb $~0x2,0x31(%ebp) # Clear IF
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jmp v86mon.7 # Finish up
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#
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||||
# Emulate STI.
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#
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/*
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* Emulate STI.
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*/
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v86sti: orb $0x2,0x31(%ebp) # Set IF
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jmp v86mon.7 # Finish up
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||||
#
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||||
# Emulate PUSHF/PUSHFD.
|
||||
#
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/*
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* Emulate PUSHF/PUSHFD.
|
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*/
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v86pushf: subl %ecx,%ebx # Adjust SP
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cmpb $0x4,%cl # 32-bit
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je v86pushf.1 # Yes
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data16 # 16-bit
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v86pushf.1: movl %edx,(%ebx) # Save flags
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jmp v86mon.6 # Finish up
|
||||
#
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||||
# Emulate IRET/IRETD.
|
||||
#
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||||
/*
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* Emulate IRET/IRETD.
|
||||
*/
|
||||
v86iret: movzwl (%ebx),%esi # Load V86 IP
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movzwl 0x2(%ebx),%edi # Load V86 CS
|
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leal 0x4(%ebx),%ebx # Adjust SP
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movl %edi,0x2c(%ebp) # Save V86 CS
|
||||
xorl %edi,%edi # No ESI adjustment
|
||||
#
|
||||
# Emulate POPF/POPFD (and remainder of IRET/IRETD).
|
||||
#
|
||||
/*
|
||||
* Emulate POPF/POPFD (and remainder of IRET/IRETD).
|
||||
*/
|
||||
v86popf: cmpb $0x4,%cl # 32-bit?
|
||||
je v86popf.1 # Yes
|
||||
movl %edx,%eax # Initialize
|
||||
@ -599,19 +599,19 @@ v86popf.1: movl (%ebx),%eax # Load flags
|
||||
andl $~V86_FLG,%edx # the
|
||||
orl %eax,%edx # flags
|
||||
jmp v86mon.5 # Finish up
|
||||
#
|
||||
# trap int 15, function 87
|
||||
# reads %es:%si from saved registers on stack to find a GDT containing
|
||||
# source and destination locations
|
||||
# reads count of words from saved %cx
|
||||
# returns success by setting %ah to 0
|
||||
#
|
||||
int15_87: pushl %eax # Save
|
||||
pushl %ebx # some information
|
||||
/*
|
||||
* trap int 15, function 87
|
||||
* reads %es:%si from saved registers on stack to find a GDT containing
|
||||
* source and destination locations
|
||||
* reads count of words from saved %cx
|
||||
* returns success by setting %ah to 0
|
||||
*/
|
||||
int15_87: pushl %eax # Save
|
||||
pushl %ebx # some information
|
||||
pushl %esi # onto the stack.
|
||||
pushl %edi
|
||||
xorl %eax,%eax # clean EAX
|
||||
xorl %ebx,%ebx # clean EBX
|
||||
xorl %eax,%eax # clean EAX
|
||||
xorl %ebx,%ebx # clean EBX
|
||||
movl 0x4(%ebp),%esi # Get user's ESI
|
||||
movl 0x3C(%ebp),%ebx # store ES
|
||||
movw %si,%ax # store SI
|
||||
@ -646,15 +646,15 @@ int15_87: pushl %eax # Save
|
||||
andb $0xfe,%dl # clear CF
|
||||
jmp v86mon.5 # Finish up
|
||||
|
||||
#
|
||||
# Reboot the machine by setting the reboot flag and exiting
|
||||
#
|
||||
/*
|
||||
* Reboot the machine by setting the reboot flag and exiting
|
||||
*/
|
||||
reboot: orb $0x1,btx_hdr+0x7 # Set the reboot flag
|
||||
jmp exit # Terminate BTX and reboot
|
||||
|
||||
#
|
||||
# Emulate INT imm8... also make sure to check if it's int 15/87
|
||||
#
|
||||
/*
|
||||
* Emulate INT imm8... also make sure to check if it's int 15/87
|
||||
*/
|
||||
v86intn: lodsb # Get int no
|
||||
cmpb $0x19,%al # is it int 19?
|
||||
je reboot # yes, reboot the machine
|
||||
@ -688,9 +688,9 @@ v86intn.3: subl %edi,%esi # From
|
||||
xorl %edi,%edi # No ESI adjustment
|
||||
andb $~0x1,%dh # Clear TF
|
||||
jmp v86mon.5 # Finish up
|
||||
#
|
||||
# Hardware interrupt jump table.
|
||||
#
|
||||
/*
|
||||
* Hardware interrupt jump table.
|
||||
*/
|
||||
intx20: push $0x8 # Int 0x20: IRQ0
|
||||
jmp int_hw # V86 int 0x8
|
||||
push $0x9 # Int 0x21: IRQ1
|
||||
@ -723,9 +723,9 @@ intx20: push $0x8 # Int 0x20: IRQ0
|
||||
jmp int_hw # V86 int 0x76
|
||||
push $0x77 # Int 0x2f: IRQ15
|
||||
jmp int_hw # V86 int 0x77
|
||||
#
|
||||
# Reflect hardware interrupts.
|
||||
#
|
||||
/*
|
||||
* Reflect hardware interrupts.
|
||||
*/
|
||||
int_hw: testb $0x2,0xe(%esp,1) # V86 mode?
|
||||
jz intusr # No
|
||||
pushl $SEL_SDATA # Address
|
||||
@ -752,14 +752,14 @@ int_hw: testb $0x2,0xe(%esp,1) # V86 mode?
|
||||
popl %ebp # saved
|
||||
popl %eax # registers
|
||||
iret # To V86 mode
|
||||
#
|
||||
# Invoke V86 interrupt from user mode, with arguments.
|
||||
#
|
||||
/*
|
||||
* Invoke V86 interrupt from user mode, with arguments.
|
||||
*/
|
||||
intx31: stc # Have btx_v86
|
||||
pushl %eax # Missing int no
|
||||
#
|
||||
# Invoke V86 interrupt from user mode.
|
||||
#
|
||||
/*
|
||||
* Invoke V86 interrupt from user mode.
|
||||
*/
|
||||
intusr: std # String ops dec
|
||||
pushl %eax # Expand
|
||||
pushl %eax # stack
|
||||
@ -844,9 +844,9 @@ intusr.5: movl %eax,%ecx # Save
|
||||
leal 0x10(%esp,1),%esp # Discard seg regs
|
||||
popa # Restore
|
||||
iret # To V86 mode
|
||||
#
|
||||
# System Call.
|
||||
#
|
||||
/*
|
||||
* System Call.
|
||||
*/
|
||||
intx30: cmpl $SYS_EXEC,%eax # Exec system call?
|
||||
jne intx30.1 # No
|
||||
pushl %ss # Set up
|
||||
@ -871,9 +871,9 @@ intx30: cmpl $SYS_EXEC,%eax # Exec system call?
|
||||
call *%eax # program
|
||||
intx30.1: orb $0x1,%ss:btx_hdr+0x7 # Flag reboot
|
||||
jmp exit # Exit
|
||||
#
|
||||
# Dump structure [EBX] to [EDI], using format string [ESI].
|
||||
#
|
||||
/*
|
||||
* Dump structure [EBX] to [EDI], using format string [ESI].
|
||||
*/
|
||||
dump.0: stosb # Save char
|
||||
dump: lodsb # Load char
|
||||
testb %al,%al # End of string?
|
||||
@ -942,9 +942,9 @@ dump.8: popl %esi # Restore
|
||||
dump.9: jmp dump.0 # Continue
|
||||
dump.10: stosb # Terminate string
|
||||
ret # To caller
|
||||
#
|
||||
# Convert EAX, AX, or AL to hex, saving the result to [EDI].
|
||||
#
|
||||
/*
|
||||
* Convert EAX, AX, or AL to hex, saving the result to [EDI].
|
||||
*/
|
||||
hex32: pushl %eax # Save
|
||||
shrl $0x10,%eax # Do upper
|
||||
call hex16 # 16
|
||||
@ -962,9 +962,9 @@ hex8.1: andb $0xf,%al # Get lower 4
|
||||
orb $0x20,%al # To lower case
|
||||
stosb # Save char
|
||||
ret # (Recursive)
|
||||
#
|
||||
# Output zero-terminated string [ESI] to the console.
|
||||
#
|
||||
/*
|
||||
* Output zero-terminated string [ESI] to the console.
|
||||
*/
|
||||
putstr.0: call putchr # Output char
|
||||
putstr: lodsb # Load char
|
||||
testb %al,%al # End of string?
|
||||
@ -975,7 +975,7 @@ putstr: lodsb # Load char
|
||||
.set SIO_FMT,SIOFMT # 8N1
|
||||
.set SIO_DIV,(115200/SIOSPD) # 115200 / SPD
|
||||
|
||||
# void sio_init(void)
|
||||
* void sio_init(void)
|
||||
|
||||
sio_init: movw $SIO_PRT+0x3,%dx # Data format reg
|
||||
movb $SIO_FMT|0x80,%al # Set format
|
||||
@ -992,14 +992,14 @@ sio_init: movw $SIO_PRT+0x3,%dx # Data format reg
|
||||
outb %al,(%dx) # DTR
|
||||
incl %edx # Line status reg
|
||||
|
||||
# void sio_flush(void)
|
||||
* 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
|
||||
|
||||
# void sio_putc(int c)
|
||||
* void sio_putc(int c)
|
||||
|
||||
sio_putc: movw $SIO_PRT+0x5,%dx # Line status reg
|
||||
xor %ecx,%ecx # Timeout
|
||||
@ -1013,7 +1013,7 @@ sio_putc.1: inb (%dx),%al # Transmitter
|
||||
outb %al,(%dx) # Write character
|
||||
sio_putc.2: ret $0x4 # To caller
|
||||
|
||||
# int sio_getc(void)
|
||||
* int sio_getc(void)
|
||||
|
||||
sio_getc: call sio_ischar # Character available?
|
||||
jz sio_getc # No
|
||||
@ -1021,7 +1021,7 @@ sio_getc.1: subb $0x5,%dl # Receiver buffer reg
|
||||
inb (%dx),%al # Read character
|
||||
ret # To caller
|
||||
|
||||
# int sio_ischar(void)
|
||||
* int sio_ischar(void)
|
||||
|
||||
sio_ischar: movw $SIO_PRT+0x5,%dx # Line status register
|
||||
xorl %eax,%eax # Zero
|
||||
@ -1029,9 +1029,9 @@ sio_ischar: movw $SIO_PRT+0x5,%dx # Line status register
|
||||
andb $0x1,%al # ready?
|
||||
ret # To caller
|
||||
|
||||
#
|
||||
# Output character AL to the serial console.
|
||||
#
|
||||
/*
|
||||
* Output character AL to the serial console.
|
||||
*/
|
||||
putchr: pusha # Save
|
||||
cmpb $10, %al # is it a newline?
|
||||
jne putchr.1 # no?, then leave
|
||||
@ -1044,9 +1044,9 @@ putchr.1: pushl %eax # Push the character
|
||||
popa # Restore
|
||||
ret # To caller
|
||||
#else
|
||||
#
|
||||
# Output character AL to the console.
|
||||
#
|
||||
/*
|
||||
* Output character AL to the console.
|
||||
*/
|
||||
putchr: pusha # Save
|
||||
xorl %ecx,%ecx # Zero for loops
|
||||
movb $SCR_MAT,%ah # Mode/attribute
|
||||
@ -1088,9 +1088,9 @@ putchr.4: movw %dx,(%ebx) # Update position
|
||||
#endif
|
||||
|
||||
.p2align 4
|
||||
#
|
||||
# Global descriptor table.
|
||||
#
|
||||
/*
|
||||
* 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
|
||||
@ -1100,15 +1100,15 @@ gdt: .word 0x0,0x0,0x0,0x0 # Null entry
|
||||
.word 0xffff,MEM_USR,0xf200,0xcf# SEL_UDATA
|
||||
.word _TSSLM,MEM_TSS,0x8900,0x0 # SEL_TSS
|
||||
gdt.1:
|
||||
#
|
||||
# Pseudo-descriptors.
|
||||
#
|
||||
/*
|
||||
* Pseudo-descriptors.
|
||||
*/
|
||||
gdtdesc: .word gdt.1-gdt-1,gdt,0x0 # GDT
|
||||
idtdesc: .word _IDTLM,MEM_IDT,0x0 # IDT
|
||||
ivtdesc: .word 0x400-0x0-1,0x0,0x0 # IVT
|
||||
#
|
||||
# IDT construction control string.
|
||||
#
|
||||
/*
|
||||
* IDT construction control string.
|
||||
*/
|
||||
idtctl: .byte 0x10, 0x8e # Int 0x0-0xf
|
||||
.word 0x7dfb,intx00 # (exceptions)
|
||||
.byte 0x10, 0x8e # Int 0x10
|
||||
@ -1120,9 +1120,9 @@ idtctl: .byte 0x10, 0x8e # Int 0x0-0xf
|
||||
.byte 0x2, 0xee # Int 0x31-0x32
|
||||
.word 0x1, intx31 # (V86, null)
|
||||
.byte 0x0 # End of string
|
||||
#
|
||||
# Dump format string.
|
||||
#
|
||||
/*
|
||||
* Dump format string.
|
||||
*/
|
||||
dmpfmt: .byte '\n' # "\n"
|
||||
.ascii "int" # "int="
|
||||
.byte 0x80|DMP_X32, 0x40 # "00000000 "
|
||||
@ -1166,8 +1166,8 @@ dmpfmt: .byte '\n' # "\n"
|
||||
.ascii "ss:esp" # "ss:esp="
|
||||
.byte 0x80|DMP_MEM|DMP_EOL,0x0 # "00 00 ... 00 00\n"
|
||||
.asciz "BTX halted\n" # End
|
||||
#
|
||||
# End of BTX memory.
|
||||
#
|
||||
/*
|
||||
* End of BTX memory.
|
||||
*/
|
||||
.p2align 4
|
||||
break:
|
||||
|
||||
@ -1,68 +1,68 @@
|
||||
#
|
||||
# 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.
|
||||
#
|
||||
/*
|
||||
* 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.
|
||||
*
|
||||
* $FreeBSD$
|
||||
*/
|
||||
|
||||
# $FreeBSD$
|
||||
/*
|
||||
* Prototype BTX loader program, written in a couple of hours. The
|
||||
* real thing should probably be more flexible, and in C.
|
||||
*/
|
||||
|
||||
#
|
||||
# Prototype BTX loader program, written in a couple of hours. The
|
||||
# real thing should probably be more flexible, and in C.
|
||||
#
|
||||
|
||||
#
|
||||
# Memory locations.
|
||||
#
|
||||
/*
|
||||
* 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
|
||||
#
|
||||
# Segment selectors.
|
||||
#
|
||||
/*
|
||||
* 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
|
||||
#
|
||||
# Paging constants.
|
||||
#
|
||||
/*
|
||||
* Paging constants.
|
||||
*/
|
||||
.set PAG_SIZ,0x1000 # Page size
|
||||
.set PAG_ENT,0x4 # Page entry size
|
||||
#
|
||||
# Screen constants.
|
||||
#
|
||||
/*
|
||||
* Screen constants.
|
||||
*/
|
||||
.set SCR_MAT,0x7 # Mode/attribute
|
||||
.set SCR_COL,0x50 # Columns per row
|
||||
.set SCR_ROW,0x19 # Rows per screen
|
||||
#
|
||||
# BIOS Data Area locations.
|
||||
#
|
||||
/*
|
||||
* BIOS Data Area locations.
|
||||
*/
|
||||
.set BDA_MEM,0x413 # Free memory
|
||||
.set BDA_SCR,0x449 # Video mode
|
||||
.set BDA_POS,0x450 # Cursor position
|
||||
#
|
||||
# Required by aout gas inadequacy.
|
||||
#
|
||||
/*
|
||||
* Required by aout gas inadequacy.
|
||||
*/
|
||||
.set SIZ_STUB,0x1a # Size of stub
|
||||
#
|
||||
# We expect to be loaded by boot2 at the origin defined in ./Makefile.
|
||||
#
|
||||
/*
|
||||
* We expect to be loaded by boot2 at the origin defined in ./Makefile.
|
||||
*/
|
||||
.globl start
|
||||
#
|
||||
# BTX program loader for ELF clients.
|
||||
#
|
||||
/*
|
||||
* BTX program loader for ELF clients.
|
||||
*/
|
||||
start: cld # String ops inc
|
||||
movl $m_logo,%esi # Identify
|
||||
call putstr # ourselves
|
||||
@ -75,9 +75,9 @@ start: cld # String ops inc
|
||||
call putstr # base memory
|
||||
#endif
|
||||
lgdt gdtdesc # Load new GDT
|
||||
#
|
||||
# Relocate caller's arguments.
|
||||
#
|
||||
/*
|
||||
* Relocate caller's arguments.
|
||||
*/
|
||||
#ifdef BTXLDR_VERBOSE
|
||||
movl $m_esp,%esi # Display
|
||||
movl %esp,%eax # caller
|
||||
@ -119,9 +119,9 @@ start_null_bi: movl $0x18,%ecx # Allocate space
|
||||
call hexout # relocation
|
||||
call putstr # message
|
||||
#endif
|
||||
#
|
||||
# Set up BTX kernel.
|
||||
#
|
||||
/*
|
||||
* Set up BTX kernel.
|
||||
*/
|
||||
movl $MEM_ESP,%esp # Set up new stack
|
||||
movl $MEM_DATA,%ebx # Data segment
|
||||
movl $m_vers,%esi # Display BTX
|
||||
@ -173,9 +173,9 @@ start_null_bi: movl $0x18,%ecx # Allocate space
|
||||
call hexout # base
|
||||
call putstr # address
|
||||
#endif
|
||||
#
|
||||
# Set up ELF-format client program.
|
||||
#
|
||||
/*
|
||||
* Set up ELF-format client program.
|
||||
*/
|
||||
cmpl $0x464c457f,(%ebx) # ELF magic number?
|
||||
je start.3 # Yes
|
||||
movl $e_fmt,%esi # Display error
|
||||
@ -252,9 +252,9 @@ start.8: xorw %ax,%ax # Data
|
||||
ljmp $0,$MEM_ENTRY # Jump to BTX entry point
|
||||
start.9:
|
||||
.code32
|
||||
#
|
||||
# Output message [ESI] followed by EAX in hex.
|
||||
#
|
||||
/*
|
||||
* Output message [ESI] followed by EAX in hex.
|
||||
*/
|
||||
hexout: pushl %eax # Save
|
||||
call putstr # Display message
|
||||
popl %eax # Restore
|
||||
@ -277,17 +277,17 @@ hexout.2: decl %esi # Adjust for inc
|
||||
popl %edi # Restore
|
||||
popl %esi # caller's
|
||||
ret # To caller
|
||||
#
|
||||
# Output zero-terminated string [ESI] to the console.
|
||||
#
|
||||
/*
|
||||
* 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
|
||||
#
|
||||
# Output character AL to the console.
|
||||
#
|
||||
/*
|
||||
* Output character AL to the console.
|
||||
*/
|
||||
putchr: pusha # Save
|
||||
xorl %ecx,%ecx # Zero for loops
|
||||
movb $SCR_MAT,%ah # Mode/attribute
|
||||
@ -326,9 +326,9 @@ putchr.3: cmpb $SCR_ROW,%dh # Beyond screen?
|
||||
putchr.4: movw %dx,(%ebx) # Update position
|
||||
popa # Restore
|
||||
ret # To caller
|
||||
#
|
||||
# Convert EAX, AX, or AL to hex, saving the result to [EDI].
|
||||
#
|
||||
/*
|
||||
* Convert EAX, AX, or AL to hex, saving the result to [EDI].
|
||||
*/
|
||||
hex32: pushl %eax # Save
|
||||
shrl $0x10,%eax # Do upper
|
||||
call hex16 # 16
|
||||
@ -349,9 +349,9 @@ hex8.1: andb $0xf,%al # Get lower 4
|
||||
|
||||
.data
|
||||
.p2align 4
|
||||
#
|
||||
# Global descriptor table.
|
||||
#
|
||||
/*
|
||||
* 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
|
||||
@ -360,9 +360,9 @@ gdt: .word 0x0,0x0,0x0,0x0 # Null entry
|
||||
gdt.1:
|
||||
gdtdesc: .word gdt.1-gdt-1 # Limit
|
||||
.long gdt # Base
|
||||
#
|
||||
# Messages.
|
||||
#
|
||||
/*
|
||||
* Messages.
|
||||
*/
|
||||
m_logo: .asciz " \nBTX loader 1.00 "
|
||||
m_vers: .asciz "BTX version is \0\n"
|
||||
e_fmt: .asciz "Error: Client format not supported\n"
|
||||
@ -390,7 +390,7 @@ m_segs: .asciz "text segment: offset="
|
||||
.asciz " memsz=\0\n"
|
||||
m_done: .asciz "Loading complete\n"
|
||||
#endif
|
||||
#
|
||||
# Uninitialized data area.
|
||||
#
|
||||
/*
|
||||
* Uninitialized data area.
|
||||
*/
|
||||
buf: # Scratch buffer
|
||||
|
||||
Loading…
Reference in New Issue
Block a user