Add btxldr, a BTX loader for ELF clients.
This commit is contained in:
Robert Nordier
parent
aa7af79537
commit
b0923a2edc
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=39091
@ -1,5 +1,5 @@
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# $Id:$
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# $Id: Makefile,v 1.1.1.1 1998/09/12 04:29:22 rnordier Exp $
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SUBDIR= btx
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SUBDIR= btx btxldr
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.include <bsd.subdir.mk>
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20
sys/boot/i386/btx/btxldr/Makefile
Normal file
20
sys/boot/i386/btx/btxldr/Makefile
Normal file
@ -0,0 +1,20 @@
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# $Id:$
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ORG=0x100000
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all: btxldr
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btxldr: btxldr.o
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.if ${OBJFORMAT} == aout
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${LD} -nostdlib -N -s -T ${ORG} -o btxldr.out btxldr.o
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dd if=btxldr.out of=${.TARGET} ibs=32 skip=1
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.else
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${LD} -N -e start -Ttext ${ORG} -o btxldr.out btxldr.o
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/usr/libexec/elf/objcopy -S -O binary btxldr.out ${.TARGET}
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.endif
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btxldr.o: btxldr.s
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${AS} ${AFLAGS} -o ${.TARGET} btxldr.s
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clean:
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rm -f btxldr btxldr.out btxldr.o
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368
sys/boot/i386/btx/btxldr/btxldr.S
Normal file
368
sys/boot/i386/btx/btxldr/btxldr.S
Normal file
@ -0,0 +1,368 @@
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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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# $Id:$
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#
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# Prototype BTX loader program, written in a couple of hours. The
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# real thing should probably be more flexible, and in C.
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#
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#
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# Memory locations.
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#
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.set MEM_STUB,0x600 # Real mode stub
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.set MEM_ESP,0x1000 # New stack pointer
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.set MEM_TBL,0x5000 # BTX page tables
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.set MEM_ENTRY,0x9010 # BTX entry point
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.set MEM_DATA,0x101000 # Data segment
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#
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# Segment selectors.
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#
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.set SEL_SCODE,0x8 # 4GB code
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.set SEL_SDATA,0x10 # 4GB data
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.set SEL_RCODE,0x18 # 64K code
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.set SEL_RDATA,0x20 # 64K data
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#
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# Paging constants.
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#
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.set PAG_SIZ,0x1000 # Page size
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.set PAG_ENT,0x4 # Page entry size
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#
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# Screen constants.
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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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.set BDA_MEM,0x413 # Free memory
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.set BDA_SCR,0x449 # Video mode
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.set BDA_POS,0x450 # Cursor position
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#
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# Required by aout gas inadequacy.
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#
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.set SIZ_STUB,0x1a # Size of stub
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#
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# We expect to be loaded by boot2 at 0x100000.
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#
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.globl start
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#
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# BTX program loader for ELF clients.
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#
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start: cld # String ops inc
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movl $m_logo,%esi # Identify
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call putstr # ourselves
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movl BDA_MEM,%eax # Get base memory
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shll $0xa,%eax # in bytes
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movl %eax,%ebp # Base of user stack
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movl $m_mem,%esi # Display
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call hexout # amount of
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call putstr # base memory
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lgdt gdtdesc # Load new GDT
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#
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# Relocate caller's arguments.
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#
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movl $m_esp,%esi # Display
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movl %esp,%eax # caller's
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call hexout # stack
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call putstr # pointer
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movl $m_args,%esi # Format string
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leal 0x4(%esp,1),%ebx # First argument
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movl $0x6,%ecx # Count
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start.1: movl (%ebx),%eax # Get argument and
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addl $0x4,%ebx # bump pointer
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call hexout # Display it
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loop start.1 # Till done
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call putstr # End message
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movl $0x48,%ecx # Allocate space
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subl %ecx,%ebp # for bootinfo
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movl 0x18(%esp,1),%esi # Source
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movl %ebp,%edi # Destination
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rep # Copy
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movsb # it
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movl %ebp,0x18(%esp,1) # Update pointer
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movl $m_rel_bi,%esi # Display
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movl %ebp,%eax # bootinfo
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call hexout # relocation
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call putstr # message
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movl $0x18,%ecx # Allocate space
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subl %ecx,%ebp # for arguments
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leal 0x4(%esp,1),%esi # Source
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movl %ebp,%edi # Destination
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rep # Copy
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movsb # them
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movl $m_rel_args,%esi # Display
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movl %ebp,%eax # argument
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call hexout # relocation
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call putstr # message
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#
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# Set up BTX kernel.
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#
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movl $MEM_ESP,%esp # Set up new stack
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movl $MEM_DATA,%ebx # Data segment
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movl $m_vers,%esi # Display BTX
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call putstr # version message
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movb 0x5(%ebx),%al # Get major version
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addb $'0',%al # Display
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call putchr # it
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movb $'.',%al # And a
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call putchr # dot
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movb 0x6(%ebx),%al # Get minor
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xorb %ah,%ah # version
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movb $0xa,%dl # Divide
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divb %dl,%al # by 10
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addb $'0',%al # Display
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call putchr # tens
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movb %ah,%al # Get units
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addb $'0',%al # Display
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call putchr # units
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call putstr # End message
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movl %ebx,%esi # BTX image
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movzwl 0x8(%ebx),%edi # Compute
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orl $PAG_SIZ/PAG_ENT-1,%edi # the
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incl %edi # BTX
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shll $0x2,%edi # load
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addl $MEM_TBL,%edi # address
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pushl %edi # Save
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movzwl 0xa(%ebx),%ecx # Image size
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pushl %ecx # Save
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rep # Relocate
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movsb # BTX
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movl %esi,%ebx # Keep place
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movl $m_rel_btx,%esi # Restore
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popl %eax # parameters
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call hexout # and
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popl %ebp # display
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movl %ebp,%eax # the
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call hexout # relocation
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call putstr # message
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addl $PAG_SIZ,%ebp # Display
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movl $m_base,%esi # the
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movl %ebp,%eax # user
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call hexout # base
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call putstr # address
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#
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# Set up ELF-format client program.
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#
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cmpl $0x464c457f,(%ebx) # ELF magic number?
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je start.3 # Yes
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movl $e_fmt,%esi # Display error
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call putstr # message
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start.2: jmp start.2 # Hang
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start.3: movl $m_elf,%esi # Display ELF
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call putstr # message
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movl $m_segs,%esi # Format string
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movl $0x2,%edi # Segment count
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movl 0x1c(%ebx),%edx # Get e_phoff
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addl %ebx,%edx # To pointer
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movzwl 0x2c(%ebx),%ecx # Get e_phnum
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start.4: cmpl $0x1,(%edx) # Is p_type PT_LOAD?
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jne start.6 # No
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movl 0x4(%edx),%eax # Display
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call hexout # p_offset
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movl 0x8(%edx),%eax # Display
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call hexout # p_vaddr
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movl 0x10(%edx),%eax # Display
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call hexout # p_filesz
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movl 0x14(%edx),%eax # Display
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call hexout # p_memsz
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call putstr # End message
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pushl %esi # Save
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pushl %edi # working
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pushl %ecx # registers
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movl 0x4(%edx),%esi # Get p_offset
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addl %ebx,%esi # as pointer
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movl 0x8(%edx),%edi # Get p_vaddr
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addl %ebp,%edi # as pointer
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movl 0x10(%edx),%ecx # Get p_filesz
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rep # Set up
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movsb # segment
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movl 0x14(%edx),%ecx # Any bytes
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subl 0x10(%edx),%ecx # to zero?
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jz start.5 # No
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xorb %al,%al # Then
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rep # zero
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stosb # them
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start.5: popl %ecx # Restore
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popl %edi # working
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popl %esi # registers
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decl %edi # Segments to do
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je start.7 # If none
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start.6: addl $0x20,%edx # To next entry
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loop start.4 # Till done
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start.7: movl $m_done,%esi # Display done
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call putstr # message
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movl $start.8,%esi # Real mode stub
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movl $MEM_STUB,%edi # Destination
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movl $SIZ_STUB,%ecx # Size
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rep # Relocate
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movsb # it
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ljmp $SEL_RCODE,$MEM_STUB # To 16-bit code
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start.8: xorl %eax,%eax # Data
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movb $SEL_RDATA,%al # selector
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movl %eax,%ss # Reload SS
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movl %eax,%ds # Reset
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movl %eax,%es # other
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movl %eax,%fs # segment
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movl %eax,%gs # limits
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movl %cr0,%eax # Switch to
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decl %eax # real
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movl %eax,%cr0 # mode
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.byte 0xea # Jump to
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.word MEM_ENTRY # BTX entry
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.word 0x0 # point
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start.9:
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#
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# Output message [ESI] followed by EAX in hex.
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#
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hexout: pushl %eax # Save
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call putstr # Display message
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popl %eax # Restore
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pushl %esi # Save
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pushl %edi # caller's
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movl $buf,%edi # Buffer
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pushl %edi # Save
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call hex32 # To hex
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xorb %al,%al # Terminate
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stosb # string
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popl %esi # Restore
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hexout.1: lodsb # Get a char
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cmpb $'0',%al # Leading zero?
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je hexout.1 # Yes
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testb %al,%al # End of string?
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jne hexout.2 # No
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decl %esi # Undo
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hexout.2: decl %esi # Adjust for inc
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call putstr # Display hex
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popl %edi # Restore
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popl %esi # caller's
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ret # To caller
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#
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# Output zero-terminated string [ESI] to the console.
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#
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putstr.0: call putchr # Output char
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putstr: lodsb # Load char
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testb %al,%al # End of string?
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jne putstr.0 # No
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ret # To caller
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#
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# Output character AL to the console.
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#
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putchr: pusha # Save
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xorl %ecx,%ecx # Zero for loops
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movb $SCR_MAT,%ah # Mode/attribute
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movl $BDA_POS,%ebx # BDA pointer
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movw (%ebx),%dx # Cursor position
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movl $0xb8000,%edi # Regen buffer (color)
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cmpb %ah,BDA_SCR-BDA_POS(%ebx) # Mono mode?
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jne putchr.1 # No
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xorw %di,%di # Regen buffer (mono)
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putchr.1: cmpb $0xa,%al # New line?
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je putchr.2 # Yes
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xchgl %eax,%ecx # Save char
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movb $SCR_COL,%al # Columns per row
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mulb %dh # * row position
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addb %dl,%al # + column
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adcb $0x0,%ah # position
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shll %eax # * 2
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xchgl %eax,%ecx # Swap char, offset
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movw %ax,(%edi,%ecx,1) # Write attr:char
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incl %edx # Bump cursor
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cmpb $SCR_COL,%dl # Beyond row?
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jb putchr.3 # No
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putchr.2: xorb %dl,%dl # Zero column
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incb %dh # Bump row
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putchr.3: cmpb $SCR_ROW,%dh # Beyond screen?
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jb putchr.4 # No
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leal 2*SCR_COL(%edi),%esi # New top line
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movw $(SCR_ROW-1)*SCR_COL/2,%cx # Words to move
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rep # Scroll
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movsl # screen
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movb $' ',%al # Space
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movb $SCR_COL,%cl # Columns to clear
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rep # Clear
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stosw # line
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movb $SCR_ROW-1,%dh # Bottom line
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putchr.4: movw %dx,(%ebx) # Update position
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popa # Restore
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ret # To caller
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#
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# Convert EAX, AX, or AL to hex, saving the result to [EDI].
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#
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hex32: pushl %eax # Save
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shrl $0x10,%eax # Do upper
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call hex16 # 16
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popl %eax # Restore
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hex16: call hex16.1 # Do upper 8
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hex16.1: xchgb %ah,%al # Save/restore
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hex8: pushl %eax # Save
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shrb $0x4,%al # Do upper
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call hex8.1 # 4
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popl %eax # Restore
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hex8.1: andb $0xf,%al # Get lower 4
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cmpb $0xa,%al # Convert
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sbbb $0x69,%al # to hex
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das # digit
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orb $0x20,%al # To lower case
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stosb # Save char
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ret # (Recursive)
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.data
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.p2align 4
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#
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# Global descriptor table.
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#
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gdt: .word 0x0,0x0,0x0,0x0 # Null entry
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.word 0xffff,0x0,0x9a00,0xcf # SEL_SCODE
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.word 0xffff,0x0,0x9200,0xcf # SEL_SDATA
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.word 0xffff,0x0,0x9a00,0x0 # SEL_RCODE
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.word 0xffff,0x0,0x9200,0x0 # SEL_RDATA
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gdt.1:
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gdtdesc: .word gdt.1-gdt-1 # Limit
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.long gdt # Base
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#
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# Messages.
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#
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m_logo: .asciz "\nBTX loader 0.01\n"
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m_mem: .asciz "Starting in protected mode (base mem=\0)\n"
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m_esp: .asciz "Arguments passed (esp=\0):\n"
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m_args: .asciz"<howto="
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.asciz" bootdev="
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.asciz" junk="
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.asciz" "
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.asciz" "
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.asciz" bootinfo=\0>\n"
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m_rel_bi: .asciz "Relocated bootinfo (size=48) to \0\n"
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m_rel_args: .asciz "Relocated arguments (size=18) to \0\n"
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m_vers: .asciz "BTX version is \0\n"
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m_rel_btx: .asciz "Relocated kernel (size=\0) to \0\n"
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m_base: .asciz "Client base address is \0\n"
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e_fmt: .asciz "Error: Client format not supported\n"
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m_elf: .asciz "Client format is ELF\n"
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m_segs: .asciz "text segment: offset="
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.asciz " vaddr="
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.asciz " filesz="
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.asciz " memsz=\0\n"
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.asciz "data segment: offset="
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.asciz " vaddr="
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.asciz " filesz="
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.asciz " memsz=\0\n"
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m_done: .asciz "Loading complete\n"
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#
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# Uninitialized data area.
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#
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buf: # Scratch buffer
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368
sys/boot/i386/btx/btxldr/btxldr.s
Normal file
368
sys/boot/i386/btx/btxldr/btxldr.s
Normal file
@ -0,0 +1,368 @@
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#
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# Copyright (c) 1998 Robert Nordier
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# All rights reserved.
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||||
#
|
||||
# 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.
|
||||
#
|
||||
|
||||
# $Id:$
|
||||
|
||||
#
|
||||
# Prototype BTX loader program, written in a couple of hours. The
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# real thing should probably be more flexible, and in C.
|
||||
#
|
||||
|
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#
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# Memory locations.
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#
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.set MEM_STUB,0x600 # Real mode stub
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.set MEM_ESP,0x1000 # New stack pointer
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.set MEM_TBL,0x5000 # BTX page tables
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.set MEM_ENTRY,0x9010 # BTX entry point
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.set MEM_DATA,0x101000 # Data segment
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#
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# Segment selectors.
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#
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.set SEL_SCODE,0x8 # 4GB code
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.set SEL_SDATA,0x10 # 4GB data
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.set SEL_RCODE,0x18 # 64K code
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.set SEL_RDATA,0x20 # 64K data
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#
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# Paging constants.
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#
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.set PAG_SIZ,0x1000 # Page size
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.set PAG_ENT,0x4 # Page entry size
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#
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# Screen constants.
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#
|
||||
.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
|
||||
#
|
||||
# Required by aout gas inadequacy.
|
||||
#
|
||||
.set SIZ_STUB,0x1a # Size of stub
|
||||
#
|
||||
# We expect to be loaded by boot2 at 0x100000.
|
||||
#
|
||||
.globl start
|
||||
#
|
||||
# BTX program loader for ELF clients.
|
||||
#
|
||||
start: cld # String ops inc
|
||||
movl $m_logo,%esi # Identify
|
||||
call putstr # ourselves
|
||||
movl BDA_MEM,%eax # Get base memory
|
||||
shll $0xa,%eax # in bytes
|
||||
movl %eax,%ebp # Base of user stack
|
||||
movl $m_mem,%esi # Display
|
||||
call hexout # amount of
|
||||
call putstr # base memory
|
||||
lgdt gdtdesc # Load new GDT
|
||||
#
|
||||
# Relocate caller's arguments.
|
||||
#
|
||||
movl $m_esp,%esi # Display
|
||||
movl %esp,%eax # caller's
|
||||
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 $0x48,%ecx # Allocate space
|
||||
subl %ecx,%ebp # for bootinfo
|
||||
movl 0x18(%esp,1),%esi # Source
|
||||
movl %ebp,%edi # Destination
|
||||
rep # Copy
|
||||
movsb # it
|
||||
movl %ebp,0x18(%esp,1) # Update pointer
|
||||
movl $m_rel_bi,%esi # Display
|
||||
movl %ebp,%eax # bootinfo
|
||||
call hexout # relocation
|
||||
call putstr # message
|
||||
movl $0x18,%ecx # Allocate space
|
||||
subl %ecx,%ebp # for arguments
|
||||
leal 0x4(%esp,1),%esi # Source
|
||||
movl %ebp,%edi # Destination
|
||||
rep # Copy
|
||||
movsb # them
|
||||
movl $m_rel_args,%esi # Display
|
||||
movl %ebp,%eax # argument
|
||||
call hexout # relocation
|
||||
call putstr # message
|
||||
#
|
||||
# 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
|
||||
movzwl 0xa(%ebx),%ecx # Image size
|
||||
pushl %ecx # Save
|
||||
rep # Relocate
|
||||
movsb # BTX
|
||||
movl %esi,%ebx # Keep place
|
||||
movl $m_rel_btx,%esi # Restore
|
||||
popl %eax # parameters
|
||||
call hexout # and
|
||||
popl %ebp # display
|
||||
movl %ebp,%eax # the
|
||||
call hexout # relocation
|
||||
call putstr # message
|
||||
addl $PAG_SIZ,%ebp # Display
|
||||
movl $m_base,%esi # the
|
||||
movl %ebp,%eax # user
|
||||
call hexout # base
|
||||
call putstr # address
|
||||
#
|
||||
# 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
|
||||
start.3: movl $m_elf,%esi # Display ELF
|
||||
call putstr # message
|
||||
movl $m_segs,%esi # Format string
|
||||
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 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
|
||||
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: movl $m_done,%esi # Display done
|
||||
call putstr # message
|
||||
movl $start.8,%esi # Real mode stub
|
||||
movl $MEM_STUB,%edi # Destination
|
||||
movl $SIZ_STUB,%ecx # Size
|
||||
rep # Relocate
|
||||
movsb # it
|
||||
ljmp $SEL_RCODE,$MEM_STUB # To 16-bit code
|
||||
start.8: xorl %eax,%eax # Data
|
||||
movb $SEL_RDATA,%al # selector
|
||||
movl %eax,%ss # Reload SS
|
||||
movl %eax,%ds # Reset
|
||||
movl %eax,%es # other
|
||||
movl %eax,%fs # segment
|
||||
movl %eax,%gs # limits
|
||||
movl %cr0,%eax # Switch to
|
||||
decl %eax # real
|
||||
movl %eax,%cr0 # mode
|
||||
.byte 0xea # Jump to
|
||||
.word MEM_ENTRY # BTX entry
|
||||
.word 0x0 # point
|
||||
start.9:
|
||||
#
|
||||
# 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
|
||||
#
|
||||
# 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.
|
||||
#
|
||||
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)
|
||||
|
||||
.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.1:
|
||||
gdtdesc: .word gdt.1-gdt-1 # Limit
|
||||
.long gdt # Base
|
||||
#
|
||||
# Messages.
|
||||
#
|
||||
m_logo: .asciz "\nBTX loader 0.01\n"
|
||||
m_mem: .asciz "Starting in protected mode (base mem=\0)\n"
|
||||
m_esp: .asciz "Arguments passed (esp=\0):\n"
|
||||
m_args: .asciz"<howto="
|
||||
.asciz" bootdev="
|
||||
.asciz" junk="
|
||||
.asciz" "
|
||||
.asciz" "
|
||||
.asciz" bootinfo=\0>\n"
|
||||
m_rel_bi: .asciz "Relocated bootinfo (size=48) to \0\n"
|
||||
m_rel_args: .asciz "Relocated arguments (size=18) to \0\n"
|
||||
m_vers: .asciz "BTX version is \0\n"
|
||||
m_rel_btx: .asciz "Relocated kernel (size=\0) to \0\n"
|
||||
m_base: .asciz "Client base address is \0\n"
|
||||
e_fmt: .asciz "Error: Client format not supported\n"
|
||||
m_elf: .asciz "Client format is ELF\n"
|
||||
m_segs: .asciz "text segment: offset="
|
||||
.asciz " vaddr="
|
||||
.asciz " filesz="
|
||||
.asciz " memsz=\0\n"
|
||||
.asciz "data segment: offset="
|
||||
.asciz " vaddr="
|
||||
.asciz " filesz="
|
||||
.asciz " memsz=\0\n"
|
||||
m_done: .asciz "Loading complete\n"
|
||||
#
|
||||
# Uninitialized data area.
|
||||
#
|
||||
buf: # Scratch buffer
|
||||
Loading…
Reference in New Issue
Block a user