dccbc08d92
files in boot2 directory are copies from legacy biosboot. Submitted by: IMAI Takeshi <take-i@ceres.dti.ne.jp>
460 lines
11 KiB
ArmAsm
460 lines
11 KiB
ArmAsm
#
|
|
# 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.
|
|
#
|
|
|
|
# $Id: btxldr.s,v 1.5 1999/01/22 13:07:17 rnordier Exp $
|
|
|
|
#
|
|
# Prototype BTX loader program, written in a couple of hours. The
|
|
# real thing should probably be more flexible, and in C.
|
|
#
|
|
|
|
#
|
|
# 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,0x101000 # Data segment
|
|
#
|
|
# Segment selectors.
|
|
#
|
|
.set SEL_SCODE,0x8 # 4GB code
|
|
.set SEL_SDATA,0x10 # 4GB data
|
|
.set SEL_RCODE,0x18 # 64K code
|
|
.set SEL_RDATA,0x20 # 64K data
|
|
#
|
|
# Paging constants.
|
|
#
|
|
.set PAG_SIZ,0x1000 # Page size
|
|
.set PAG_ENT,0x4 # Page entry size
|
|
#
|
|
# Screen constants.
|
|
#
|
|
.ifdef PC98
|
|
.set SCR_MAT,0xe1 # Mode/attribute
|
|
.else
|
|
.set SCR_MAT,0x7 # Mode/attribute
|
|
.endif
|
|
.set SCR_COL,0x50 # Columns per row
|
|
.set SCR_ROW,0x19 # Rows per screen
|
|
#
|
|
# BIOS Data Area locations.
|
|
#
|
|
.ifdef PC98
|
|
.set BDA_MEM,0xa1501 # Free memory
|
|
.set BDA_POS,0xa153e # Cursor position
|
|
.else
|
|
.set BDA_MEM,0x413 # Free memory
|
|
.set BDA_SCR,0x449 # Video mode
|
|
.set BDA_POS,0x450 # Cursor position
|
|
.endif
|
|
#
|
|
# 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
|
|
.ifdef PC98
|
|
cli
|
|
gdcwait.1: inb $0x60,%al
|
|
testb $0x04,%al
|
|
jz gdcwait.1
|
|
movb $0xe0,%al
|
|
outb %al,$0x62
|
|
nop
|
|
gdcwait.2: inb $0x60,%al
|
|
testb $0x01,%al
|
|
jz gdcwait.2
|
|
inb $0x62,%al
|
|
movb %al,%dl
|
|
inb $0x62,%al
|
|
movb %al,%dh
|
|
inb $0x62,%al
|
|
inb $0x62,%al
|
|
inb $0x62,%al
|
|
shlw $1,%dx
|
|
movl $BDA_POS,%ebx
|
|
movw %dx,(%ebx)
|
|
.endif
|
|
movl $m_logo,%esi # Identify
|
|
call putstr # ourselves
|
|
movzwl BDA_MEM,%eax # Get base memory
|
|
.ifdef PC98
|
|
andl $0x7,%eax
|
|
incl %eax
|
|
shll $0x11,%eax # in bytes
|
|
.else
|
|
shll $0xa,%eax # in bytes
|
|
.endif
|
|
movl %eax,%ebp # Base of user stack
|
|
movl $m_mem,%esi # Display
|
|
call dhexout # amount of
|
|
call dputstr # base memory
|
|
lgdt gdtdesc # Load new GDT
|
|
#
|
|
# Relocate caller's arguments.
|
|
#
|
|
movl $m_esp,%esi # Display
|
|
movl %esp,%eax # caller's
|
|
call dhexout # stack
|
|
call dputstr # 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 dhexout # Display it
|
|
loop start.1 # Till done
|
|
call dputstr # 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 dhexout # relocation
|
|
call dputstr # 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 dhexout # relocation
|
|
call dputstr # 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 dhexout # and
|
|
popl %ebp # display
|
|
movl %ebp,%eax # the
|
|
call dhexout # relocation
|
|
call dputstr # message
|
|
addl $PAG_SIZ,%ebp # Display
|
|
movl $m_base,%esi # the
|
|
movl %ebp,%eax # user
|
|
call dhexout # base
|
|
call dputstr # 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 dputstr # 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 dhexout # p_offset
|
|
movl 0x8(%edx),%eax # Display
|
|
call dhexout # p_vaddr
|
|
movl 0x10(%edx),%eax # Display
|
|
call dhexout # p_filesz
|
|
movl 0x14(%edx),%eax # Display
|
|
call dhexout # p_memsz
|
|
call dputstr # 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 dputstr # 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.
|
|
#
|
|
dhexout:
|
|
.ifndef BTXLDR_VERBOSE
|
|
ret
|
|
.endif
|
|
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.
|
|
#
|
|
dputstr:
|
|
.ifndef BTXLDR_VERBOSE
|
|
ret
|
|
.else
|
|
jmp putstr
|
|
.endif
|
|
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.
|
|
#
|
|
dputchr:
|
|
.ifndef BTXLDR_VERBOSE
|
|
ret
|
|
.endif
|
|
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
|
|
.ifdef PC98
|
|
movl $0xa0000,%edi # Regen buffer (color)
|
|
.else
|
|
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)
|
|
.endif
|
|
putchr.1: cmpb $0xa,%al # New line?
|
|
je putchr.2 # Yes
|
|
.ifdef PC98
|
|
movw %dx,%cx
|
|
movb %al,(%edi,%ecx,1) # Write char
|
|
addl $0x2000,%ecx
|
|
movb %ah,(%edi,%ecx,1) # Write attr
|
|
addw $0x2,%dx
|
|
jmp putchr.3
|
|
putchr.2: movw %dx,%ax
|
|
movb $SCR_COL*2,%dl
|
|
div %dl
|
|
incb %al
|
|
mul %dl
|
|
movw %ax,%dx
|
|
putchr.3: cmpw $SCR_COL*SCR_ROW*2,%dx
|
|
.else
|
|
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?
|
|
.endif
|
|
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
|
|
.ifdef PC98
|
|
xorb %ah,%ah
|
|
.endif
|
|
movb $SCR_COL,%cl # Columns to clear
|
|
rep # Clear
|
|
stosw # line
|
|
.ifdef PC98
|
|
movw $(SCR_ROW-1)*SCR_COL*2,%dx
|
|
putchr.4: movw %dx,(%ebx) # Update position
|
|
shrw $1,%dx
|
|
gdcwait.3: inb $0x60,%al
|
|
testb $0x04,%al
|
|
jz gdcwait.3
|
|
movb $0x49,%al
|
|
outb %al,$0x62
|
|
movb %dl,%al
|
|
outb %al,$0x60
|
|
movb %dh,%al
|
|
outb %al,$0x60
|
|
.else
|
|
movb $SCR_ROW-1,%dh # Bottom line
|
|
putchr.4: movw %dx,(%ebx) # Update position
|
|
.endif
|
|
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 1.00 "
|
|
m_vers: .asciz "BTX version is \0\n"
|
|
e_fmt: .asciz "Error: Client format not supported\n"
|
|
#.ifdef BTXLDR_VERBOSE
|
|
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_rel_btx: .asciz "Relocated kernel (size=\0) to \0\n"
|
|
m_base: .asciz "Client base address is \0\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"
|
|
#.endif
|
|
#
|
|
# Uninitialized data area.
|
|
#
|
|
buf: # Scratch buffer
|