Use real_to_prot (etc) from stand/lib.

Add a patchable header for boot parameters (eg console type).
This commit is contained in:
dsl 2003-10-09 10:36:26 +00:00
parent 3d4b6a197d
commit 44ac426707
1 changed files with 16 additions and 306 deletions

View File

@ -1,4 +1,4 @@
/* $NetBSD: start_pxe.S,v 1.1 2003/10/09 09:42:25 dsl Exp $ */ /* $NetBSD: start_pxe.S,v 1.2 2003/10/09 10:36:26 dsl Exp $ */
/* /*
* Copyright 2001 Wasabi Systems, Inc. * Copyright 2001 Wasabi Systems, Inc.
@ -43,18 +43,24 @@
*/ */
#include <machine/asm.h> #include <machine/asm.h>
#include <sys/bootblock.h>
.text .text
ENTRY(start) ENTRY(start)
.code16 .code16
/* Boot parameter area in same format as boot and bootxx */
jmp 1f
.balign 4
.long X86_BOOT_MAGIC_PXE
bootparams:
.long 1f - bootparams
#include <boot_params.S>
.space 4 * 4 /* some spare */
1:
# start is loaded at 0x0:0x7c00 but we want 0x7c0:0x0 # start is loaded at 0x0:0x7c00 but we want 0x7c0:0x0
# ljmp to the next instruction to adjust %cs # ljmp to the next instruction to adjust %cs
ljmp $0x7c0, $start1 ljmp $0x7c0, $2f
2:
# Our stack XXX probably not!
.space 1024
start1:
# set up %ds # set up %ds
xorl %eax, %eax xorl %eax, %eax
mov %cs, %ax mov %cs, %ax
@ -64,23 +70,7 @@ start1:
mov %ax, %ss mov %ax, %ss
movl $0xfffc, %esp /* stack at top of 64k segment */ movl $0xfffc, %esp /* stack at top of 64k segment */
movl %eax, _C_LABEL(ourseg) call gdt_fixup
shll $4, %eax
/* fix up GDT entries for bootstrap */
#define FIXUP(gdt_index) \
movw %ax, gdt+gdt_index+2; \
movb %bl, gdt+gdt_index+4
shldl $16, %eax, %ebx
FIXUP(bootcodeseg)
FIXUP(bootrealseg)
FIXUP(bootdataseg)
/* fix up GDT pointer */
addl $gdt, %eax
movl %eax, gdtarg+2
/* change to protected mode */ /* change to protected mode */
calll _C_LABEL(real_to_prot) calll _C_LABEL(real_to_prot)
@ -115,290 +105,10 @@ _C_LABEL(exit):
/* call ROM BASIC */ /* call ROM BASIC */
int $0x18 int $0x18
#else #else
10:
cli cli
hlt hlt
jmp 10b
#endif #endif
efail: .asciz "Boot fail\r\n" efail: .asciz "Boot fail\r\n"
ENTRY(ourseg)
.long 0
/**************************************************************************
GLOBAL DESCRIPTOR TABLE
**************************************************************************/
#ifdef __ELF__
.align 16
#else
.align 4
#endif
gdt:
.word 0, 0
.byte 0, 0x00, 0x00, 0
#ifdef SUPPORT_LINUX /* additional dummy */
.word 0, 0
.byte 0, 0x00, 0x00, 0
#endif
/* kernel code segment */
.globl flatcodeseg
flatcodeseg = . - gdt
.word 0xffff, 0
.byte 0, 0x9f, 0xcf, 0
/* kernel data segment */
.globl flatdataseg
flatdataseg = . - gdt
.word 0xffff, 0
.byte 0, 0x93, 0xcf, 0
/* boot code segment, base will be patched */
bootcodeseg = . - gdt
.word 0xffff, 0
.byte 0, 0x9e, 0x4f, 0
/* boot data segment, base will be patched */
bootdataseg = . - gdt
.word 0xffff, 0
.byte 0, 0x92, 0x4f, 0
/* 16 bit real mode, base will be patched */
bootrealseg = . - gdt
.word 0xffff, 0
.byte 0, 0x9e, 0x00, 0
/* limits (etc) for data segment in real mode */
bootrealdata = . - gdt
.word 0xffff, 0
.byte 0, 0x92, 0x00, 0
gdtlen = . - gdt
#ifdef __ELF__
.align 16
#else
.align 4
#endif
gdtarg:
.word gdtlen-1 /* limit */
.long 0 /* addr, will be inserted */
CR0_PE = 0x1
/*
* real_to_prot()
* transfer from real mode to protected mode.
*/
ENTRY(real_to_prot)
.code16
# guarantee that interrupt is disabled when in prot mode
cli
pushl %eax
push %cs /* ensure %ds is correct */
pop %ds
# load the gdtr
lgdt gdtarg
# set the PE bit of CR0
movl %cr0, %eax
orl $CR0_PE, %eax
movl %eax, %cr0
# make intrasegment jump to flush the processor pipeline and
# reload CS register
ljmp $bootcodeseg, $xprot
xprot:
.code32
# we are in USE32 mode now
# set up the protected mode segment registers : DS, SS, ES
mov $bootdataseg, %ax
mov %ax, %ds
mov %ax, %ss
mov %ax, %es
popl %eax
ret
/*
* prot_to_real()
* transfer from protected mode to real mode
*/
ENTRY(prot_to_real)
.code32
pushl %eax
# set up a dummy stack frame for the second seg change.
# Adjust the intersegment jump instruction following
# the clearing of protected mode bit.
# This is self-modifying code, but we need a writable
# code segment, and an intersegment return does not give us that.
movl _C_LABEL(ourseg), %eax
movw %ax, xreal-2
/*
* Load the segment registers while still in protected mode.
* Otherwise the control bits don't get changed.
* The correct values are loaded later.
*/
movw $bootrealdata, %ax
movw %ax, %ds
movw %ax, %es
movw %ax, %ss
# Change to use16 mode.
ljmp $bootrealseg, $x16
x16:
.code16
# clear the PE bit of CR0
movl %cr0, %eax
andl $~CR0_PE, %eax
movl %eax, %cr0
ljmp $0, $xreal /* segment overwritten above */
xreal:
.code16
# we are in real mode now
# set up the real mode segment registers : DS, SS, ES
mov %cs, %ax
mov %ax, %ds
mov %ax, %ss
mov %ax, %es
sti
popl %eax
retl
/*
* pbzero(dst, cnt)
* where dst is a physical address and cnt is the length
*/
ENTRY(pbzero)
.code32
pushl %ebp
movl %esp, %ebp
pushl %es
pushl %edi
cld
# set %es to point at the flat segment
movl $flatdataseg, %eax
mov %ax, %es
movl 8(%ebp), %edi # destination
movl 12(%ebp), %ecx # count
xorl %eax, %eax # value
rep
stosb
popl %edi
popl %es
popl %ebp
ret
/*
* vpbcopy(src, dst, cnt)
* where src is a virtual address and dst is a physical address
*/
ENTRY(vpbcopy)
.code32
pushl %ebp
movl %esp, %ebp
pushl %es
pushl %esi
pushl %edi
cld
# set %es to point at the flat segment
movl $flatdataseg, %eax
mov %ax, %es
movl 8(%ebp), %esi # source
movl 12(%ebp), %edi # destination
movl 16(%ebp), %ecx # count
rep
movsb
popl %edi
popl %esi
popl %es
popl %ebp
ret
/*
* pvbcopy(src, dst, cnt)
* where src is a physical address and dst is a virtual address
*/
ENTRY(pvbcopy)
.code32
pushl %ebp
movl %esp, %ebp
pushl %ds
pushl %esi
pushl %edi
cld
# set %ds to point at the flat segment
movl $flatdataseg, %eax
mov %ax, %ds
movl 8(%ebp), %esi # source
movl 12(%ebp), %edi # destination
movl 16(%ebp), %ecx # count
rep
movsb
popl %edi
popl %esi
popl %ds
popl %ebp
ret
ENTRY(vtophys)
movl _C_LABEL(ourseg), %eax
shll $4, %eax
addl 4(%esp), %eax
ret
/*
* message: write the error message in %ds:%esi to the console
*/
message:
.code16
/*
* BIOS call "INT 10H Function 0Eh" to write character to console
* Call with %ah = 0x0e
* %al = character
* %bh = page
* %bl = foreground color
*/
pushl %eax
pushl %ebx
pushl %edx
nextb:
cld
lodsb # load a byte into %al
testb %al, %al
jz done
movb $0x0e, %ah
movw $0x0001, %bx
int $0x10
jmp nextb
done:
popl %edx
popl %ebx
popl %eax
ret