freebsd-dev/sys/i386/apm/apm_init/apm_init.S
Poul-Henning Kamp 64bb0d8861 On my GW2K Handbook486 this code would reset when called from locore.s
I think I have narrowed this down to the stack being overflown.  I have
taken the push/pop of %fs out, it shouldn't be needed anyway, but the
real & correct solution might to save the registers on the stack in
locore.s before calling this stuff.
1994-10-01 21:29:50 +00:00

208 lines
5.1 KiB
ArmAsm

/*
* LP (Laptop Package)
*
* Copyright (C) 1994 by HOSOKAWA, Tatsumi <hosokawa@mt.cs.keio.ac.jp>
*
* This software may be used, modified, copied, and distributed, in
* both source and binary form provided that the above copyright and
* these terms are retained. Under no circumstances is the author
* responsible for the proper functioning of this software, nor does
* the author assume any responsibility for damages incurred with its
* use.
*
* Sep., 1994 Implemented on FreeBSD 1.1.5.1R (Toshiba AVS001WD)
*
* $Id: apm_init.S,v 1.2 1994/10/01 05:12:29 davidg Exp $
*/
/*
* If you want to know the specification of APM BIOS, see the following
* documentations,
*
* [1] Intel Corporation and Microsoft Corporation, "Advanced Power
* Management, The Next Generation, Version 1.0", Feb.,1992.
*
* [2] Intel Corporation and Microsoft Corporation, "Advanced Power
* Management (APM) BIOS Interface Specification Revision 1.1",
* Sep.,1993, Intel Order Number: 241704-001, Microsoft Part
* Number: 781-110-X01
*
* or contact
*
* APM Support Desk (Intel Corporation, US)
* TEL: (800)628-8686
* FAX: (916)356-6100.
*/
.file "apm_init.S"
#define ASM
#include "real_prot.h"
#include "apm_bios.h"
#include "apm_segments.h"
/*
* APM BIOS initializer
*
* Return value:
* %eax 0xfffffff Can't find APM BIOS
* 0xffffffe Don't support 32bit connection
* 0xffffffd Connection error
* otherwise APM version (16bit BCD format)
* %ebx APM cs entry offset (32bit)
* %ecx lower 16bit APM 16bit cs base (real mode segment)
* upper 16bit APM 32bit cs base (real mode segment)
* %edx lower 16bit APM ds limit (real mode segment)
* upper 16bit [Reserved]
* %esi lower 16bit APM cs limit (APM 1.1 or later)
* upper 16bit APM ds limit (APM 1.1 or later)
* %edi bit0 = 1 16bit protected mode interface supported
* bit1 = 1 32bit protected mode interface supported
* bit2 = 1 "CPU idle" call slows processor clock speed
* bit3 = 1 APM BIOS Power Management disabled
* bit4 = 1 APM BIOS Power Management disengaged
*/
.text
ENTRY(apm_init)
cli /* disable interrupt */
pushl %ebp /* save original base pointer */
/* ebp is used as a register variable */
/*
* save old data segments: We assume that %ds == %es && %ds == %ss
*/
movw %ds, %ax
movw %ax, %fs
movw $(APM_INIT_DS_SEL), %ax /* initializer data segment */
movw %ax, %ds
movw %ax, %es
movw %ax, %ss
movl %esp, old_esp /* save original stack pointer */
movl $0x10000, %esp /* setup temporary stack */
/* (note that it isn't 0x00000000) */
sidt EXT(Idtr_prot) /* save current IDT */
call EXT(prot_to_real) /* return to real mode */
/*
* APM installation check
*/
movb $(APM_BIOS), %ah
movb $(APM_INSTCHECK), %al
data32
movl $(PMDV_APMBIOS), %ebx
sti
int $(SYSTEM_BIOS) /* call system BIOS */
cli
jnc 1f /* if found, goto 1f */
data32
call EXT(real_to_prot) /* come back again to protected mode */
movl $(APMINI_CANTFIND), apm_version
/* can't find APM BIOS */
jmp finish
1:
movl %eax, %edx /* actually, movw %ax, %dx */
/* save the value of %ax */
data32
call EXT(real_to_prot) /* come back again to protected mode */
cmpb $0x50, %bh /* %bh == 'P'? */
jnz 1f
cmpb $0x4d, %bl /* %bl == 'M'? */
jz 2f
1:
movl $(APMINI_CANTFIND), apm_version
/* can't find APM BIOS */
jmp finish
2:
testl $(APM_32BIT_SUPPORT), %ecx
/* supports 32bit connection? */
jnz 1f
movl $(APMINI_NOT32BIT), apm_version
/* don't support 32bit connection */
jmp finish
1:
movl %edx, apm_version
andl $0x0000ffff, %ecx
movl %ecx, apm_flags
/*
* APM Protected Mode 32-bit Interface Connect
*/
call EXT(prot_to_real) /* return to real mode */
movb $(APM_BIOS), %ah
movb $(APM_PROT32CONNECT), %al
data32
movl $(PMDV_APMBIOS), %ebx
sti
int $(SYSTEM_BIOS)
cli
jnc 1f /* if successed, go to 1f */
data32
call EXT(real_to_prot)
movl $(APMINI_CONNECTERR), apm_version
/* connection error */
jmp finish
1:
/* save PM 32bit code segment into %bp */
movl %eax, %ebp /* actually, movw %ax, %bp */
data32
call EXT(real_to_prot)
movl $0x0000ffff, %eax
andl %eax, %ebp /* 32bit cs base */
andl %eax, %ecx /* 16bit cs base */
andl %eax, %edx /* ds base */
andl %eax, %esi /* cs length (APM 1.1 or later) */
andl %eax, %edi /* ds length (APM 1.1 or later) */
/* %ebx is code offset */
/* pack 32bit cs and 16bit cs into %ecx */
shll $16, %ebp
orl %ebp, %ecx
/* pack cs length and ds length into %esi */
shll $16, %edi
orl %edi, %esi
finish:
cli
lidt EXT(Idtr_prot) /* restore old IDTR */
movl old_esp, %esp /* restore old stack pointer */
movl apm_version, %ebp /* stored to %eax later */
movl apm_flags, %edi
#if 0
movw $(BOOTSTRAP_DS_SEL), %ax
/* restore old data segments */
#else
movw %fs, %ax
#endif
movw %ax, %ss
movw %ax, %es
movw %ax, %ds
movl %ebp, %eax
popl %ebp /* restore old base pointer */
lret /* restore old code segment */
.data
.globl EXT(ouraddr)
LEXT(ouraddr)
.long APM_OURADDR
old_esp:
.long 0
apm_version:
.long 0
apm_flags:
.long 0
old_ds:
.word 0
old_es:
.word 0
old_ss:
.word 0