i386 ELF bootloader. developed with weingart@

1 files changed, 90 insertions, 129 deletions

diff --git a/sys/arch/i386/stand/libsa/gidt.S b/sys/arch/i386/stand/libsa/gidt.S
index 6faa27cfb73..85a32bb55bd 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 1.24 2001/09/17 13:10:09 deraadt Exp $	*/
+/*	$OpenBSD: gidt.S,v 1.25 2003/04/17 03:43:18 drahn Exp $	*/
 
 /*
  * Copyright (c) 1997 Michael Shalayeff
@@ -41,9 +41,6 @@
 #undef _LOCORE
 #include <assym.h>
 
-#define addr32  .byte 0x67
-#define data32  .byte 0x66
-
 #define	SNULL	0x00
 #define S32TEXT	0x08
 #define	S32DATA	0x10
@@ -52,26 +49,17 @@
 
 #ifdef GIDT_DEBUG
 #define	gidt_debug0		; \
-	movl	$0xb8000, %eax	; \
-	movl	$0x47314730, (%eax)
+	mov	$0xb8000, %eax	; \
+	mov	$0x47314730, (%eax)
 #define	gidt_debug1		; \
-	data32			; \
-	movl	$(0xb8000 - LINKADDR), %eax	; \
-	data32			; \
-	addr32			; \
-	movl	$0x4f314f30, (%eax)
+	mov	$(0xb8000 - LINKADDR), %eax	; \
+	mov	$0x4f314f30, (%eax)
 #define	gidt_debug2		; \
-	data32			; \
-	movl	$0xb8004, %eax	; \
-	data32			; \
-	addr32			; \
-	movl	$0x47334732, (%eax)
+	mov	$0xb8004, %eax	; \
+	mov	$0x47334732, (%eax)
 #define	gidt_debug3		; \
-	data32			; \
-	movl	$0xb8004, %eax	; \
-	data32			; \
-	addr32			; \
-	movl	$0x4f334f32, (%eax)
+	mov	$0xb8004, %eax	; \
+	mov	$0x4f334f32, (%eax)
 #define gidt_debug4		; \
 	movl	$0xb8008, %eax	; \
 	movl	$0x47344733, (%eax)
@@ -86,58 +74,47 @@
 #define prot2real						\
 	gidt_debug0;						\
 								\
-	movl	$S16DATA, %ax;					\
-	/* ljmp	$S16TEXT, $1f */;				\
-	.byte	0xea;		/* Change to 16bit mode */	\
-	.long	1f - LINKADDR;					\
-	.word	S16TEXT;					\
+	ljmp	$S16TEXT, $1f - LINKADDR;			\
 1:								\
-	movl	%ax, %ds;					\
-	movl	%ax, %es;					\
+	.code16;						\
+	movw	$S16DATA, %ax;					\
+	mov	%ax, %ds;					\
+	mov	%ax, %es;					\
 	gidt_debug1;						\
 								\
 	movl	%cr0, %eax;	/* disable pmmm */		\
-	data32;							\
 	andl 	$~CR0_PE, %eax;					\
 	movl	%eax, %cr0;					\
 								\
-	/* ljmp	(LINKADDR >> 4), $1f */;			\
-	.byte	0xea;		/* load real mode cs:ip */	\
-	.word	1f;						\
-	.word	(LINKADDR >> 4);				\
+	/* reload real cs:ip */					\
+	data32 ljmp	$(LINKADDR >> 4), $1f - LINKADDR;	\
 1:								\
-	data32;							\
-	xorl	%eax, %eax;	/* setup: %ds, %es, %ss */	\
-	movl	%ax, %ds;					\
-	movl	%ax, %es;					\
-	movl	%ax, %ss;					\
+	xor	%ax, %ax;	/* setup: %ds, %es, %ss */	\
+	mov	%ax, %ds;					\
+	mov	%ax, %es;					\
+	mov	%ax, %ss;					\
 								\
 	gidt_debug2;						\
 								\
-	addr32;							\
-	data32;							\
-	lidt	Idtr_real;	/* load idtr for real mode */
+	data32 addr32 lidt Idtr_real;	/* load idtr for real mode */
 
 #define real2prot						\
 	gidt_debug3;						\
 								\
-	addr32;							\
-	data32;							\
-	lgdt	Gdtr;		/* load the gdtr */		\
+	data32 addr32 lgdt Gdtr;	/* load the gdtr */	\
 								\
 	movl	%cr0, %eax;	/* enable pmmm */		\
-	data32;							\
 	orl	$CR0_PE, %eax;					\
 	movl	%eax, %cr0;					\
 								\
-	data32;							\
-	ljmp	$S32TEXT, $1f;   /* reload %cs,flush pipeline */\
+	data32 ljmp	$S32TEXT, $1f;   /* reload %cs,flush pipeline */\
 1:								\
+	.code32;						\
 	/* reload 32bit %ds, %ss, %es */			\
-	movl	$S32DATA, %eax;					\
-	movl	%ax, %ds;					\
-	movl	%ax, %ss;					\
-	movl	%ax, %es;					\
+	mov	$S32DATA, %eax;					\
+	mov	%ax, %ds;					\
+	mov	%ax, %ss;					\
+	mov	%ax, %es;					\
 								\
 	gidt_debug4;						\
 								\
@@ -148,6 +125,7 @@
 	.globl	_C_LABEL(BIOS_regs)
 
 	.text
+	.code32
 	.globl	_ASM_LABEL(pmm_init)
 	.globl	_C_LABEL(_rtt)
 
@@ -187,30 +165,21 @@ ENTRY(_rtt)
 	movl	$0, %esp	/* segment violation */
 	ret
 
-	.align	3, 0x90
+	.align	8, 0x90
 pmm_init:
-	/* reload new gdt */
-	lgdt	Gdtr
-	ljmp	$S32TEXT, $1f
-1:	
-	movl	$S32DATA, %eax
-	movl	%eax, %ds
-	movl	%eax, %ss
-	movl	%eax, %es
-	movl	%eax, %fs
-	movl	%eax, %gs
-
 	/* load idtr for interrupts */
 	lidt	Idtr
 	ret
 
+
 #define IPROC(n)	X/**/n
 #define IEMU(n)		IPROC(emu/**/n)
-	.align 3
+	.align 8, 0x90
 idt:
 #define idte(e)	\
-	.word IPROC(e), S32TEXT, (0x80|SDT_SYS386TGT) << 8, (LINKADDR >> 16)
-		/* internal (0-31) */
+	.short	IPROC(e); .short (S32TEXT); \
+	.short	((0x80|SDT_SYS386TGT) << 8); .short (LINKADDR >> 16)
+/* internal (0-31) */
 	idte(de); idte(db); idte(nmi); idte(bp); idte(of); idte(br)
 	idte(ud); idte(nm); idte(df);  idte(fo); idte(ts); idte(np)
 	idte(ss); idte(gp); idte(pf);  idte(xx); idte(mf); idte(ac)
@@ -235,15 +204,15 @@ Idtr:	.word	. - idt - 1
 	.long	idt
 	.word	0
 
-	.align	3
+	.align	8
 Idtr_real:	.word	1023
 		.long	0
 		.word	0
 
-	.align	3
+	.align	8
 Idtr_reset:	.long	0, 0
 
-	.align	3
+	.align	8
 gdt:
 		/* 0x00 : null */
 	.space	8
@@ -276,6 +245,7 @@ gdt:
 	.byte	0xf | 0 | 0 | 0		# hilimit, xx, 16bit, byte granularity
 	.byte	(LINKADDR >> 20) & 0xff	# hibase
 
+.globl Gdtr
 Gdtr:	.word	. - gdt - 1
 	.long	gdt
 	.word	0
@@ -344,109 +314,100 @@ IEMUENT(44); IEMUENT(45); IEMUENT(46); IEMUENT(47)
  *
  */
 	.globl	EMUh
-	.align	3, 0x90
+	.align	8, 0x90
 EMUh:
 	/* save %eax */
-	movl	%eax, 3f
-	popl	%eax
+	mov	%eax, 3f
+	pop	%eax
 
-	pushal
-	pushl	%ds
-	pushl	%es
-	pushl	%fs
-	pushl	%gs
+	pusha
+	push	%ds
+	push	%es
+	push	%fs
+	push	%gs
 
 	/* save BIOS int vector */
-	movb	%al, intno
+	mov	%al, intno
 
 	prot2real
 
-	pushl	%ds
+	push	%ds
 
-	addr32
-	movl	_C_LABEL(BIOS_regs)+(BIOSR_ES), %eax
-	movl	%ax, %es
-	addr32
-	movl	_C_LABEL(BIOS_regs)+(BIOSR_DS), %eax
-	movl	%ax, %ds
+	addr32  mov _C_LABEL(BIOS_regs)+(BIOSR_ES), %eax
+	mov	%ax, %es
+	addr32  mov _C_LABEL(BIOS_regs)+(BIOSR_DS), %eax
+	mov	%ax, %ds
 
-	data32
-	# movl	$Leax, %eax
-	.byte	0xb8
-3:	.long	0x90909090	/* restore %eax */
+	# data32 movl $Leax, %eax
+	.byte	0x66, 0xb8
+3:	.long	0x90909090
 
 	;sti
 	int	$0
 intno	= . - 1
 	;cli
 
-	popl	%ds
+	pop	%ds
 
-	addr32
-	data32
-	movl	%ebx, _C_LABEL(BIOS_regs)+(BIOSR_BX)
-	movl	%es, %bx
-	addr32
-	movl	%bx, _C_LABEL(BIOS_regs)+(BIOSR_ES)
-	movb	%ah, %bh	/* save flags to return to caller */
+	addr32 mov %ebx, _C_LABEL(BIOS_regs)+(BIOSR_BX)
+	mov	%es, %bx
+	addr32 mov %ebx, _C_LABEL(BIOS_regs)+(BIOSR_ES)
+	movb	%ah, %bh
 	lahf
 	xchgb	%ah, %bh
 
-	addr32
-	data32
-	movl	%eax, 2f	/* save %eax */
+	addr32 mov %eax, 2f
 
 	real2prot
 
-	# movl	$Leax, %eax
-	.byte	0xb8
-2:	.long	0x90909090	/* eax */
+	# movl $Leax, %eax
+	.byte 0xb8
+2:	.long 0x90909090
 
 	/* pass BIOS return values back to caller */
-	movl	%eax, 0xb*4(%esp)
-	movl	%ecx, 0xa*4(%esp)
-	movl	%edx, 0x9*4(%esp)
+	mov	%eax, 0xb*4(%esp)
+	mov	%ecx, 0xa*4(%esp)
+	mov	%edx, 0x9*4(%esp)
 	movb	%bh , 0xe*4(%esp)
 
 	/* clear NT flag in eflags */
 	/* Martin Fredriksson <martin@gbg.netman.se> */
 	pushf
-	popl	%eax
-	andl	$0xffffbfff, %eax
-	pushl	%eax
+	pop	%eax
+	and	$0xffffbfff, %eax
+	push	%eax
 	popf
 
 	/* save registers into save area */
-	movl	%eax, _C_LABEL(BIOS_regs)+BIOSR_AX
-	movl	%ecx, _C_LABEL(BIOS_regs)+BIOSR_CX
-	movl	%edx, _C_LABEL(BIOS_regs)+BIOSR_DX
-	movl	%ebp, _C_LABEL(BIOS_regs)+BIOSR_BP
-	movl	%esi, _C_LABEL(BIOS_regs)+BIOSR_SI
-	movl	%edi, _C_LABEL(BIOS_regs)+BIOSR_DI
-
-	popl	%gs
-	popl	%fs
-	popl	%es
-	popl	%ds
-	popal
+	mov	%eax, _C_LABEL(BIOS_regs)+BIOSR_AX
+	mov	%ecx, _C_LABEL(BIOS_regs)+BIOSR_CX
+	mov	%edx, _C_LABEL(BIOS_regs)+BIOSR_DX
+	mov	%ebp, _C_LABEL(BIOS_regs)+BIOSR_BP
+	mov	%esi, _C_LABEL(BIOS_regs)+BIOSR_SI
+	mov	%edi, _C_LABEL(BIOS_regs)+BIOSR_DI
+
+	pop	%gs
+	pop	%fs
+	pop	%es
+	pop	%ds
+	popa
 	iret
 
 /* Call buffer at 07c0:0000 in real mode to simulate a BIOS boot */
 ENTRY(bootbuf)
-	popl	%eax		/* Don't need return address */
-	popl	%esi		/* Buffer */
-	popl	%edx		/* Device */
+	pop	%eax		/* Don't need return address */
+	pop	%esi		/* Buffer */
+	pop	%edx		/* Device */
 	prot2real		/* Switch */
 
 	/* Set up stack */
 	cli
-	xorl	%ax, %ax
-	movl	%ax, %ss
-	data32
-	movl	$0xfffc, %esp
+	xor	%ax, %ax
+	mov	%ax, %ss
+	mov	$0xfffc, %esp
 	sti
 
 	/* Jump to buffer */
-	addr32
 	ljmp $0x0, $0x7c00
 
+	.end