diff options
| -rw-r--r-- | sys/arch/i386/stand/Makefile.inc | 14 | ||||
| -rw-r--r-- | sys/arch/i386/stand/libsa/Makefile | 19 | ||||
| -rw-r--r-- | sys/arch/i386/stand/libsa/biosdev.c | 17 | ||||
| -rw-r--r-- | sys/arch/i386/stand/libsa/gidt.S | 282 | ||||
| -rw-r--r-- | sys/arch/i386/stand/libsa/real_prot.S | 166 |
5 files changed, 224 insertions, 274 deletions
diff --git a/sys/arch/i386/stand/Makefile.inc b/sys/arch/i386/stand/Makefile.inc index d94df93ebd7..dbeaa4bf257 100644 --- a/sys/arch/i386/stand/Makefile.inc +++ b/sys/arch/i386/stand/Makefile.inc @@ -1,11 +1,12 @@ -# $OpenBSD: Makefile.inc,v 1.6 1997/04/11 19:07:07 weingart Exp $ +# $OpenBSD: Makefile.inc,v 1.7 1997/04/18 01:28:00 mickey Exp $ #CPPFLAGS+=-nostdinc -I/sys CPPFLAGS+=-Wall -Werror -I. -Imachine -SACFLAGS+=-Wa,-R -fno-common -fpack-struct -fno-builtin -fomit-frame-pointer +SACFLAGS+=-Wa,-R -fpack-struct -fno-builtin -fomit-frame-pointer CPPFLAGS+=-D_STANDALONE -# CPPFLAGS+=-DSAVE_MEMORY /* XXX - Does *NOT* work */ +# CPPFLAGS+=-DSAVE_MEMORY # CPPFLAGS+=-DDEBUG +# CPPFLAGS+=-DGIDT_DEBUG # CPPFLAGS+=-DBIOS_DEBUG # CPPFLAGS+=-DEXEC_DEBUG # CPPFLAGS+=-DALLOC_TRACE @@ -13,11 +14,10 @@ CPPFLAGS+=-D_STANDALONE # CPPFLAFS+=-DUNIX_DEBUG # CPPFLAFS+=-DBOOTP_DEBUG -DNETIF_DEBUG -DETHER_DEBUG # CPPFLAGS+=-DNFS_DEBUG -DRPC_DEBUG -DRARP_DEBUG -START=0x1000 -HEAP_START=0x10000 -HEAP_LIMIT=0x40000 +START=0x10000 +HEAP_LIMIT=0x50000 BOOTREL=0x3000 BOOTMAGIC=0xdeadbeef -NO_NET=no_net +# NO_NET=no_net BINDIR= /usr/mdec diff --git a/sys/arch/i386/stand/libsa/Makefile b/sys/arch/i386/stand/libsa/Makefile index 5e757fc4f5c..b2f03c14fe8 100644 --- a/sys/arch/i386/stand/libsa/Makefile +++ b/sys/arch/i386/stand/libsa/Makefile @@ -1,4 +1,4 @@ -# $OpenBSD: Makefile,v 1.8 1997/04/15 20:01:55 mickey Exp $ +# $OpenBSD: Makefile,v 1.9 1997/04/18 01:28:01 mickey Exp $ LIB= sa @@ -8,14 +8,18 @@ DIR_SA= $S/lib/libsa DIR_KERN=$S/lib/libkern CFLAGS+=$(SACFLAGS) -D__INTERNAL_LIBSA_CREAD -CFLAGS+=-DHEAP_START=$(HEAP_START) -DHEAP_LIMIT=$(HEAP_LIMIT) +CFLAGS+=-DSTART=$(START) -DHEAP_LIMIT=$(HEAP_LIMIT) CFLAGS+=${DEBUGFLAGS} -I${.CURDIR} -I${.CURDIR}/.. CFLAGS+=-I$(S)/lib/libsa -I$(S) AS+= -R -#AS+= -Wa,-a +AS+= -Wa,-a + +# i386 stuff (so, it will possibly load in the same 64k) +SRCS= unixsys.S bioscom.S biosdisk.S bioskbd.S biostime.S biosmem.S gidt.S \ + debug_i386.S dev_i386.c exec_i386.c biosdev.c gateA20.c memprobe.c # stand routines -SRCS= alloc.c exit.c exec.c getfile.c gets.c globals.c strcmp.c strlen.c \ +SRCS+= alloc.c exit.c exec.c getfile.c gets.c globals.c strcmp.c strlen.c \ strncmp.c memcmp.c memcpy.c memset.c printf.c strerror.c strncpy.c # math for cd9660 @@ -35,12 +39,7 @@ SRCS+= bootp.c bootparam.c rarp.c SRCS+= ufs.c nfs.c cd9660.c # debugger -SRCS+= debug.c debug_aout.c debug_i386.S - -# i386 stuff -SRCS+= asm.S bioscom.S biosdev.c biosdisk.S bioskbd.S biostime.S biosmem.S \ - dev_i386.c gateA20.c memprobe.c real_prot.S unixsys.S exec_i386.c \ - gidt.S +SRCS+= debug.c debug_aout.c NOPROFILE=noprofile NOPIC=nopic diff --git a/sys/arch/i386/stand/libsa/biosdev.c b/sys/arch/i386/stand/libsa/biosdev.c index 696a37611d8..e6ee0edd8c7 100644 --- a/sys/arch/i386/stand/libsa/biosdev.c +++ b/sys/arch/i386/stand/libsa/biosdev.c @@ -1,4 +1,4 @@ -/* $OpenBSD: biosdev.c,v 1.8 1997/04/17 19:03:20 weingart Exp $ */ +/* $OpenBSD: biosdev.c,v 1.9 1997/04/18 01:28:01 mickey Exp $ */ /* * Copyright (c) 1996 Michael Shalayeff @@ -263,7 +263,7 @@ biosstrategy(void *devdata, int rw, { u_int8_t error = 0; register struct biosdisk *bd = (struct biosdisk *)devdata; - register size_t i, nsect, n; + register size_t i, nsect, n, spt; register const struct bd_error *p = bd_errors; nsect = (size + DEV_BSIZE-1) / DEV_BSIZE; @@ -278,15 +278,20 @@ biosstrategy(void *devdata, int rw, buf, rsize, bd->biosdev, bd->bsddev); #endif + /* handle floppies w/ different from drive geometry */ + if (!(bd->biosdev & 0x80)) + spt = bd->disklabel.d_nsectors; + else + spt = BIOSNSECTS(bd->dinfo); + for (i = 0; error == 0 && i < nsect; i += n, blk += n, buf += n * DEV_BSIZE) { register int cyl, hd, sect, j; void *bb; - btochs(blk, cyl, hd, sect, - BIOSNHEADS(bd->dinfo), BIOSNSECTS(bd->dinfo)); - if ((sect + (nsect - i)) >= BIOSNSECTS(bd->dinfo)) - n = BIOSNSECTS(bd->dinfo) - sect; + btochs(blk, cyl, hd, sect, BIOSNHEADS(bd->dinfo), spt); + if ((sect + (nsect - i)) >= spt) + n = spt - sect; else n = nsect - i; diff --git a/sys/arch/i386/stand/libsa/gidt.S b/sys/arch/i386/stand/libsa/gidt.S index 1653a0d21d9..56fc268e84b 100644 --- a/sys/arch/i386/stand/libsa/gidt.S +++ b/sys/arch/i386/stand/libsa/gidt.S @@ -1,4 +1,4 @@ -/* $OpenBSD: gidt.S,v 1.3 1997/04/09 08:39:37 mickey Exp $ */ +/* $OpenBSD: gidt.S,v 1.4 1997/04/18 01:28:02 mickey Exp $ */ /* * Copyright (c) 1997 Michael Shalayeff @@ -31,6 +31,9 @@ * SUCH DAMAGE. * */ + + .file "gidt.S" + #include <machine/asm.h> #include <machine/psl.h> #define _LOCORE @@ -45,7 +48,6 @@ .data .globl _Gdtr - .globl _codeseg .align 3 gdt: @@ -67,17 +69,23 @@ gdt: .byte 0 # hibase /* 0x18 : 16 bit code */ .word 0xFFFF # lolimit - .word 0 # lobase - .byte 0 # midbase + .word (START & 0xffff) # lobase + .byte (START >> 16) & 0xff # midbase .byte SDT_MEMERA | 0 | 0x80 # RXAC, dpl = 0, present - .byte 0x0 | 0 | 0 | 0 # hilimit, xx, 16bit, byte granularity - .byte 0 # hibase + .byte 0xf | 0 | 0 | 0 # hilimit, xx, 16bit, byte granularity + .byte (START >> 20) & 0xff # hibase + /* 0x20 : 16 bit data */ + .word 0xFFFF # lolimit + .word (START & 0xffff) # lobase + .byte (START >> 16) & 0xff # midbase + .byte SDT_MEMRWA | 0 | 0x80 # RXAC, dpl = 0, present + .byte 0xf | 0 | 0 | 0 # hilimit, xx, 16bit, byte granularity + .byte (START >> 20) & 0xff # hibase + _Gdtr: .word . - gdt - 1 .long gdt .word 0 -_codeseg: .long 0 - .globl _Idtr_real .align 3 _Idtr_real: @@ -92,59 +100,58 @@ _Idtr_reset: .globl _Idtr_prot .align 3 -idt: /* - * We beleive that all the boot code fits into - * 64k, so no need for high 16 bit of procedure address (; - * - */ -#define IPROC(n) X/**/n -#define IDTENTRY(proc) \ - .word IPROC(proc) /* lo offset handler */ ; \ - .word 0x8 /* handler %cs */ ; \ - .byte 0 /* reserved */ ; \ - .byte 0x80 | SDT_SYS386TGT /* present, dpl=0, 32bit trap gate */ ; \ - .word 0 /* hi offset handler */ - - IDTENTRY(de) /* #DE divide by zero */ - IDTENTRY(db) /* #DB debug */ - IDTENTRY(nmi) /* NMI */ - IDTENTRY(bp) /* #BP breakpoint */ - IDTENTRY(of) /* #OF overflow */ - IDTENTRY(br) /* #BR BOUND range exceeded */ - IDTENTRY(ud) /* #UD invalid opcode */ - IDTENTRY(nm) /* #NM device not available */ - IDTENTRY(df) /* #DF double fault */ - IDTENTRY(fo) /* #FO coprocessor segment overrun */ - IDTENTRY(ts) /* #TS innvalid TSS */ - IDTENTRY(np) /* #NP segmant not present */ - IDTENTRY(ss) /* #SS stack fault */ - IDTENTRY(gp) /* #GP general protection */ - IDTENTRY(pf) /* #PF page fault */ - IDTENTRY(xx) /* Intel reserved */ - IDTENTRY(mf) /* #MF floating point error */ - IDTENTRY(ac) /* #AC alignment check */ - IDTENTRY(mc) /* #MC machine check */ - /* Intel reserved (19-31) */ - IDTENTRY(xx); IDTENTRY(xx); IDTENTRY(xx); IDTENTRY(xx) - IDTENTRY(xx); IDTENTRY(xx); IDTENTRY(xx); IDTENTRY(xx) - IDTENTRY(xx); IDTENTRY(xx); IDTENTRY(xx); IDTENTRY(xx) - IDTENTRY(xx) - /* Maskable interrupts(32-255) */ - /* BIOS entry points (32-63) */ -#define IBIOS(n) IPROC(bios/**/n) -#define IDTBIOS(n) IDTENTRY(bios/**/n) - IDTBIOS(0); IDTBIOS(1); IDTBIOS(2); IDTBIOS(3); IDTBIOS(4) - IDTBIOS(5); IDTBIOS(6); IDTBIOS(7); IDTBIOS(8); IDTBIOS(9) - IDTBIOS(10); IDTBIOS(11); IDTBIOS(12); IDTBIOS(13); IDTBIOS(14) - IDTBIOS(15); IDTBIOS(16); IDTBIOS(17); IDTBIOS(18); IDTBIOS(19) - IDTBIOS(20); IDTBIOS(21); IDTBIOS(22); IDTBIOS(23) - /* DOS entry points */ +idt: + .space 32*8, 0 /* internal (0-31) */ + /* Maskable interrupts (32-255) */ + .space 32*8, 0 /* BIOS entry points (32-63) */ + .space 16*8, 0 /* DOS entry points (64-80) */ _Idtr_prot: .word . - idt - 1 .long idt .text +#define IPROC(n) X/**/n +#define IBIOS(n) IPROC(bios/**/n) +#define IDOS(n) IPROC(dos/**/n) + + .globl idt_init +idt_init: + pushl %edi + + movl $idt, %edi + +#define fixe(p) \ + movl $ IPROC(p), %eax; \ + stosw; /* lo offset handler */ \ + movw $0x8, (%edi); /* handler %cs */ \ + incl %edi; incl %edi; \ + incl %edi; /* reserved */ \ + movb $(0x80|SDT_SYS386TGT), (%edi); /* 32bit trap gate */ \ + incl %edi; \ + shrl $16, %eax; \ + stosw; /* hi offset handler */ + + fixe(de); fixe(db); fixe(nmi); fixe(bp); fixe(of); fixe(br) + fixe(ud); fixe(nm); fixe(df); fixe(fo); fixe(ts); fixe(np) + fixe(ss); fixe(gp); fixe(pf); fixe(xx); fixe(mf); fixe(ac) + fixe(mc) + fixe(xx); fixe(xx); fixe(xx); fixe(xx); fixe(xx); fixe(xx) + fixe(xx); fixe(xx); fixe(xx); fixe(xx); fixe(xx); fixe(xx) + fixe(xx) + +#define fixb(b) fixe(bios/**/b) + fixb(0); fixb(1); fixb(2); fixb(3); fixb(4); fixb(5) + fixb(6); fixb(7); fixb(8); fixb(9); fixb(10); fixb(11) + fixb(12); fixb(13); fixb(14); fixb(15); fixb(16); fixb(17) + fixb(18); fixb(19); fixb(20); fixb(21); fixb(22); fixb(23) + fixb(24); fixb(25); fixb(26); fixb(27); fixb(28); fixb(29) + fixb(30); fixb(31) + +#define fixd(d) fixe(dos/**/b) + + popl %edi + ret #define IENTRY(name,type) \ IPROC(name): \ @@ -158,33 +165,33 @@ IPROC(name): \ IPROC(xx): pushl $1 - pushl $256 + pushl $T_RESERVED jmp 1f -IENTRY_ERR(de,0,T_DIVIDE) -IENTRY_ERR(db,0,T_TRCTRAP) -IENTRY_ERR(nmi,0,T_NMI) -IENTRY_ERR(bp,0,T_BPTFLT) -IENTRY_ERR(of,0,T_OFLOW) -IENTRY_ERR(br,0,T_BOUND) -IENTRY_ERR(ud,0,T_PRIVINFLT) -IENTRY_ERR(nm,0,T_DNA) -IENTRY(df,T_DOUBLEFLT) -IENTRY_ERR(fo,0,T_FPOPFLT) -IENTRY(ts,T_TSSFLT) -IENTRY(np,T_SEGNPFLT) -IENTRY(ss,T_STKFLT) -IENTRY(gp,T_PROTFLT) -IENTRY(pf,T_PAGEFLT) -IENTRY_ERR(mf,0,T_ARITHTRAP) -IENTRY(ac,T_ALIGNFLT) -IENTRY(mc,T_MACHK) +IENTRY_ERR(de,0,T_DIVIDE) /* #DE divide by zero */ +IENTRY_ERR(db,0,T_TRCTRAP) /* #DB debug */ +IENTRY_ERR(nmi,0,T_NMI) /* NMI */ +IENTRY_ERR(bp,0,T_BPTFLT) /* #BP breakpoint */ +IENTRY_ERR(of,0,T_OFLOW) /* #OF overflow */ +IENTRY_ERR(br,0,T_BOUND) /* #BR BOUND range exceeded */ +IENTRY_ERR(ud,0,T_PRIVINFLT) /* #UD invalid opcode */ +IENTRY_ERR(nm,0,T_DNA) /* #NM device not available */ +IENTRY(df,T_DOUBLEFLT) /* #DF double fault */ +IENTRY_ERR(fo,0,T_FPOPFLT) /* #FO coprocessor segment overrun */ +IENTRY(ts,T_TSSFLT) /* #TS innvalid TSS */ +IENTRY(np,T_SEGNPFLT) /* #NP segmant not present */ +IENTRY(ss,T_STKFLT) /* #SS stack fault */ +IENTRY(gp,T_PROTFLT) /* #GP general protection */ +IENTRY(pf,T_PAGEFLT) /* #PF page fault */ +IENTRY_ERR(mf,0,T_ARITHTRAP) /* #MF floating point error */ +IENTRY(ac,T_ALIGNFLT) /* #AC alignment check */ +IENTRY(mc,T_MACHK) /* #MC machine check */ .globl alltraps 1: /* save on jumps */ jmp alltraps -#define IBIOSENT(n) IBIOS(n): pushl %eax; movb $n, %al ; jmp 1f +#define IBIOSENT(n) IBIOS(n): pushl $n; jmp BIOSh IBIOSENT(0); IBIOSENT(1); IBIOSENT(2); IBIOSENT(3) IBIOSENT(4); IBIOSENT(5); IBIOSENT(6); IBIOSENT(7) @@ -192,38 +199,143 @@ IBIOSENT(8); IBIOSENT(9); IBIOSENT(10); IBIOSENT(11) IBIOSENT(12); IBIOSENT(13); IBIOSENT(14); IBIOSENT(15) IBIOSENT(16); IBIOSENT(17); IBIOSENT(18); IBIOSENT(19) IBIOSENT(20); IBIOSENT(21); IBIOSENT(22); IBIOSENT(23) +IBIOSENT(24); IBIOSENT(25); IBIOSENT(26); IBIOSENT(27) +IBIOSENT(28); IBIOSENT(29); IBIOSENT(30); IBIOSENT(31) - .text - .globl _real_to_prot, _prot_to_real -1: - movb %al, intno - popl %eax +/* + * entry point for BIOS real-mode interface + * all the magic for real-prot mode switching is here + * + * Call: %eax, %ecx, %edx, %ebx, %ebp, %esi, %ds, %di==real mode %es + * Return: %eax, %edx, %ecx, %eflags (as returned from BIOS) + * + */ + .globl BIOSh +BIOSh: pushal pushl %ds pushl %es - call _prot_to_real + /* save %eax */ + movl %eax, 2f + + /* save BIOS int vector */ + movb 10*4(%esp), %al + movb %al, intno + + /* setup 16bit labels in ljmps */ +#ifdef GIDT_DEBUG + movl $0xb8000, %eax + movl $0x47314730, (%eax) +#endif + movl $0x20, %eax + + # ljmp $0x18, $2f + .byte 0xea /* Change to 16bit mode */ + .long 1f - START + .word 0x18 +1: + movl %ax, %ds +#ifdef GIDT_DEBUG + data32 + movl $(0xb8000 - START), %eax + data32 + addr32 + movl $0x4f314f30, (%eax) +#endif + movl %cr0, %eax /* disable prot mode memory management */ + data32 + andl $~CR0_PE, %eax + movl %eax, %cr0 + + # ljmp (START >> 16), $4f + .byte 0xea /* load real mode cs:ip */ + .word 1f + .word (START >> 4) +1: + xorl %eax, %eax /* setup: %ds, %es, %ss */ + movl %ax, %ds + movl %ax, %ss movl %di, %es +#ifdef GIDT_DEBUG + data32 + movl $0xb8004, %eax + data32 + addr32 + movl $0x47334732, (%eax) +#endif + + addr32 + data32 + lidt _Idtr_real /* load idtr for DOS/BIOS operations */ + + data32 + # movl Leax, %eax + .byte 0xb8 +2: .long 0x90909090 /* restore %eax */ + + sti int $0 -intno = . - 1 +intno = . - 1 - movb %ah, %bh + movb %ah, %bh /* save flags to return to caller */ lahf xchgb %ah, %bh + cli /* no maskable interrupts in prot mode */ + + addr32 + data32 + movl %eax, 2f /* save %eax */ + +#ifdef GIDT_DEBUG + data32 + movl $0xb8004, %eax + data32 + addr32 + movl $0x4f334f32, (%eax) +#endif + + addr32 + data32 + lgdt _C_LABEL(Gdtr) /* load the gdtr */ + + movl %cr0, %eax /* enable prot mode memory management */ + data32 + orl $CR0_PE, %eax + movl %eax, %cr0 + data32 - call _real_to_prot + ljmp $0x08, $1f /* reload %cs, and flush pipeline */ +1: + /* reload 32bit %ds, %ss, %es */ + movl $0x10, %eax + movl %ax, %ds + movl %ax, %ss + +#ifdef GIDT_DEBUG + movl $0xb8008, %eax + movl $0x47344733, (%eax) +#endif + + /* load idtr for debugger and DOS/BIOS iface */ + lidt _Idtr_prot + + # movl Leax, %eax + .byte 0xb8 +2: .long 0x90909090 /* eax */ /* pass BIOS return values back to caller */ movl %eax, 0x9*4(%esp) movl %ecx, 0x8*4(%esp) movl %edx, 0x7*4(%esp) - movb %bh , 0xc*4(%esp) + movb %bh , 0xd*4(%esp) popl %es popl %ds popal + incl %esp; incl %esp; incl %esp; incl %esp iret diff --git a/sys/arch/i386/stand/libsa/real_prot.S b/sys/arch/i386/stand/libsa/real_prot.S deleted file mode 100644 index b04d5545335..00000000000 --- a/sys/arch/i386/stand/libsa/real_prot.S +++ /dev/null @@ -1,166 +0,0 @@ -/* $OpenBSD: real_prot.S,v 1.5 1997/04/09 08:39:42 mickey Exp $ */ - -/* - * Mach Operating System - * Copyright (c) 1992, 1991 Carnegie Mellon University - * All Rights Reserved. - * - * Permission to use, copy, modify and distribute this software and its - * documentation is hereby granted, provided that both the copyright - * notice and this permission notice appear in all copies of the - * software, derivative works or modified versions, and any portions - * thereof, and that both notices appear in supporting documentation. - * - * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" - * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR - * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. - * - * Carnegie Mellon requests users of this software to return to - * - * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU - * School of Computer Science - * Carnegie Mellon University - * Pittsburgh PA 15213-3890 - * - * any improvements or extensions that they make and grant Carnegie Mellon - * the rights to redistribute these changes. - * - * from: Mach, Revision 2.2 92/04/04 11:34:13 rpd - */ - - -/* - Copyright 1988, 1989, 1990, 1991, 1992 - by Intel Corporation, Santa Clara, California. - - All Rights Reserved - -Permission to use, copy, modify, and distribute this software and -its documentation for any purpose and without fee is hereby -granted, provided that the above copyright notice appears in all -copies and that both the copyright notice and this permission notice -appear in supporting documentation, and that the name of Intel -not be used in advertising or publicity pertaining to distribution -of the software without specific, written prior permission. - -INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE -INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, -IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR -CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM -LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT, -NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION -WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. -*/ - .file "real_prot.S" - -#include <machine/asm.h> -#include <machine/specialreg.h> - -#define addr32 .byte 0x67 -#define data32 .byte 0x66 - - .data - - .globl _codeseg - .globl _Gdtr - .globl _Idtr_prot - .globl _Idtr_real - - .text - -/* - * - * real_to_prot() - * transfer from real mode to protected mode. - */ - -ENTRY(real_to_prot) - /* guarantee that interrupts are disabled when in prot mode */ - cli - addr32 - data32 - movl %eax, 2f - - /* load the gdtr */ - addr32 - data32 - lgdt _C_LABEL(Gdtr) - - /* set the PE bit of CR0 */ - movl %cr0, %eax - data32 - orl $CR0_PE, %eax - movl %eax, %cr0 - - /* - * make intrasegment jump to flush the processor pipeline and - * reload CS register - */ - data32 - ljmp $0x08, $1f - -1: /* - * we are in USE32 mode now - * set up the protected mode segment registers : DS, SS, ES - */ - movl $0x10, %eax - movl %ax, %ds - movl %ax, %ss - movl %ax, %es - - /* load idtr for debugger and BIOS iface */ - lidt _Idtr_prot - # movl Leax, %eax - .byte 0xb8 -2: .long 0 /* eax */ - ret - -/* - * - * prot_to_real() - * transfer from protected mode to real mode - * - */ - -ENTRY(prot_to_real) - - movl %eax, 4f - movl _codeseg, %eax - movw %ax, 2f - - /* Change to use16 mode. */ - ljmp $0x18, $1f -1: - /* clear the PE bit of CR0 */ - movl %cr0, %eax - data32 - andl $~CR0_PE, %eax - movl %eax, %cr0 - - data32 - # ljmp _codeseg, $2f - .byte 0xea - .long 3f -2: .word 0 -3: - /* setup: %ds, %es, %ss */ - movl %cs, %ax - movl %ax, %ds - movl %ax, %ss - movl %ax, %es - - /* load idtr for BIOS operations */ - addr32 - data32 - lidt _Idtr_real - - addr32 - data32 - # movl Leax, %eax - .byte 0xb8 -4: .long 0 /* %eax */ - - sti - data32 - ret - |