Dynamically build the Interrupt Descriptor Table (IDT), instead of using

a static table. This allows the IDT to be placed in .bss and avoids the
"relocation truncated" errors that result from the linker trying to put
a 32-bit address into a 16-bit hole.

With input from Marco Peereboom.

ok weingart@

4 files changed, 104 insertions, 71 deletions

diff --git a/sys/arch/amd64/stand/boot/srt0.S b/sys/arch/amd64/stand/boot/srt0.S
index ccd3eff0ed2..b0780b36ade 100644
--- a/sys/arch/amd64/stand/boot/srt0.S
+++ b/sys/arch/amd64/stand/boot/srt0.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: srt0.S,v 1.1 2004/02/03 12:09:47 mickey Exp $	*/
+/*	$OpenBSD: srt0.S,v 1.2 2012/10/09 11:39:57 jsing Exp $	*/
 
 /*
  * Copyright (c) 1997 Michael Shalayeff
@@ -73,7 +73,6 @@ _start:
 	movl	%edx, _C_LABEL(bios_bootdev)
 
 	/* Now do it all */
-	call	_ASM_LABEL(pmm_init)
 #ifdef DEBUG
 	movl	$0xb80a4, %ebx
 	movl	$0x07520752, (%ebx)
@@ -86,7 +85,7 @@ _start:
 	cld
 	rep;	stosb
 
+	call	_ASM_LABEL(pmm_init)
 	call	_C_LABEL(boot)
 
 	jmp	_C_LABEL(_rtt)
-
diff --git a/sys/arch/amd64/stand/libsa/gidt.S b/sys/arch/amd64/stand/libsa/gidt.S
index 325433b45dc..df5ab7cf1ec 100644
--- a/sys/arch/amd64/stand/libsa/gidt.S
+++ b/sys/arch/amd64/stand/libsa/gidt.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: gidt.S,v 1.7 2012/10/08 12:46:37 jsing Exp $	*/
+/*	$OpenBSD: gidt.S,v 1.8 2012/10/09 11:39:57 jsing Exp $	*/
 
 /*
  * Copyright (c) 1997 Michael Shalayeff
@@ -147,7 +147,7 @@ ENTRY(_rtt)
 #endif
 
 	/* Try to cause a triple fault... */
-	lidt    Idtr_reset
+	lidt	Idtr_reset
 	xorl	%eax, %eax
 	divl	%eax, %eax
 
@@ -158,26 +158,33 @@ ENTRY(_rtt)
 	movl	$0, %esp	/* segment violation */
 	ret
 
-	.align	8, 0x90
-pmm_init:
-	/* load idtr for interrupts */
-	lidt	Idtr
+#define IPROC(n)	X##n
+#define IEMU(n)		IPROC(emu##n)
+
+create_idt_entry:
+	movw	%ax, (%ebx)
+	movw	$S32TEXT, 2(%ebx)
+	movw	$((0x80|SDT_SYS386TGT) << 8), 4(%ebx)
+	shr	$16, %eax
+	movw	%ax, 6(%ebx)
+	addl	$8, %ebx
 	ret
 
+	.align	8, 0x90
+pmm_init:
 
-#ifdef __STDC__
-#define IPROC(n)	X##n
-#define IEMU(n)		IPROC(emu##n)
-#else
-#define IPROC(n)	X/**/n
-#define IEMU(n)		IPROC(emu/**/n)
-#endif
-	.align 8, 0x90
-idt:
 #define idte(e)	\
-	.short	IPROC(e); .short (S32TEXT); \
-	.short	((0x80|SDT_SYS386TGT) << 8); .short (LINKADDR >> 16)
-/* internal (0-31) */
+	movl $IPROC(e), %eax; call create_idt_entry
+#define idtb(b)	idte(emu##b)
+
+	/* Build interrupt descriptor table. */
+	/* Maskable interrupts (32-255) */
+	movl	$idt, %ebx
+	movl	$Idtr, %eax
+	movw	$(640 - 1), (%eax)
+	movl	%ebx, 2(%eax)
+
+	/* 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)
@@ -185,14 +192,7 @@ idt:
 	idte(xx); idte(xx); idte(xx);  idte(xx); idte(xx); idte(xx)
 	idte(xx); idte(xx); idte(xx);  idte(xx); idte(xx); idte(xx)
 	idte(xx) 
-		/* Maskable interrupts (32-255) */
-		/* BIOS entry points (32-63) */
-		/* DOS entry points (64-80) */
-#ifdef __STDC__
-#define idtb(b)	idte(emu##b)
-#else
-#define idtb(b)	idte(emu/**/b)
-#endif
+	/* BIOS entry points (32-63) */
 	idtb(0);  idtb(1);  idtb(2);  idtb(3);  idtb(4);  idtb(5)
 	idtb(6);  idtb(7);  idtb(8);  idtb(9);  idtb(10); idtb(11)
 	idtb(12); idtb(13); idtb(14); idtb(15); idtb(16); idtb(17)
@@ -201,20 +201,37 @@ idt:
 	idtb(30); idtb(31); idtb(32); idtb(33); idtb(34); idtb(35)
 	idtb(36); idtb(37); idtb(38); idtb(39); idtb(40); idtb(41)
 	idtb(42); idtb(43); idtb(44); idtb(45); idtb(46); idtb(47)
+	/* DOS entry points (64-80) */
+
+#undef idtb
 #undef idte
+
+	/* load idtr for interrupts */
+	lidt	Idtr
+	ret
+
+	.bss
+	.align 8, 0x90
+idt:
+	/* IDT has 80 entries at 8 bytes each. */
+	.space  640
+
 	.globl	Idtr
-Idtr:	.word	. - idt - 1
-	.long	idt
+Idtr:	.word	0  // 640 - 1
+	.long	0  // idt
 	.word	0
 
+	.data
 	.align	8
 	.globl	Idtr_real
-Idtr_real:	.word	1023
-		.long	0
-		.word	0
+Idtr_real:
+	.word	1023
+	.long	0
+	.word	0
 
 	.align	8
-Idtr_reset:	.long	0, 0
+Idtr_reset:
+	.long	0, 0
 
 	.align	8
 gdt:
@@ -254,6 +271,7 @@ Gdtr:	.word	. - gdt - 1
 	.long	gdt
 	.word	0
 
+	.text
 #define IENTRY(name,type) \
 IPROC(name): \
 	pushl	$type ; \
@@ -286,7 +304,6 @@ 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 */
-
 1:
 	cli
 	hlt
diff --git a/sys/arch/i386/stand/boot/srt0.S b/sys/arch/i386/stand/boot/srt0.S
index 9a1d6264df3..81e3d7b4f7d 100644
--- a/sys/arch/i386/stand/boot/srt0.S
+++ b/sys/arch/i386/stand/boot/srt0.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: srt0.S,v 1.14 2003/11/22 09:18:25 grange Exp $	*/
+/*	$OpenBSD: srt0.S,v 1.15 2012/10/09 11:39:57 jsing Exp $	*/
 
 /*
  * Copyright (c) 1997 Michael Shalayeff
@@ -73,7 +73,6 @@ _start:
 	movl	%edx, _C_LABEL(bios_bootdev)
 
 	/* Now do it all */
-	call	_ASM_LABEL(pmm_init)
 #ifdef DEBUG
 	movl	$0xb80a4, %ebx
 	movl	$0x07520752, (%ebx)
@@ -86,7 +85,7 @@ _start:
 	cld
 	rep;	stosb
 
+	call	_ASM_LABEL(pmm_init)
 	call	_C_LABEL(boot)
 
 	jmp	_C_LABEL(_rtt)
-
diff --git a/sys/arch/i386/stand/libsa/gidt.S b/sys/arch/i386/stand/libsa/gidt.S
index 6ea7e8323d4..0dd8922618d 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 1.33 2012/10/08 12:46:37 jsing Exp $	*/
+/*	$OpenBSD: gidt.S,v 1.34 2012/10/09 11:39:57 jsing Exp $	*/
 
 /*
  * Copyright (c) 1997 Michael Shalayeff
@@ -148,7 +148,7 @@ ENTRY(_rtt)
 #endif
 
 	/* Try to cause a triple fault... */
-	lidt    Idtr_reset
+	lidt	Idtr_reset
 	xorl	%eax, %eax
 	divl	%eax, %eax
 
@@ -159,26 +159,33 @@ ENTRY(_rtt)
 	movl	$0, %esp	/* segment violation */
 	ret
 
-	.align	8, 0x90
-pmm_init:
-	/* load idtr for interrupts */
-	lidt	Idtr
+#define IPROC(n)	X##n
+#define IEMU(n)		IPROC(emu##n)
+
+create_idt_entry:
+	movw	%ax, (%ebx)
+	movw	$S32TEXT, 2(%ebx)
+	movw	$((0x80|SDT_SYS386TGT) << 8), 4(%ebx)
+	shr	$16, %eax
+	movw	%ax, 6(%ebx)
+	addl	$8, %ebx
 	ret
 
+	.align	8, 0x90
+pmm_init:
 
-#ifdef __STDC__
-#define IPROC(n)	X##n
-#define IEMU(n)		IPROC(emu##n)
-#else
-#define IPROC(n)	X/**/n
-#define IEMU(n)		IPROC(emu/**/n)
-#endif
-	.align 8, 0x90
-idt:
 #define idte(e)	\
-	.short	IPROC(e); .short (S32TEXT); \
-	.short	((0x80|SDT_SYS386TGT) << 8); .short (LINKADDR >> 16)
-/* internal (0-31) */
+	movl $IPROC(e), %eax; call create_idt_entry
+#define idtb(b)	idte(emu##b)
+
+	/* Build interrupt descriptor table. */
+	/* Maskable interrupts (32-255) */
+	movl	$idt, %ebx
+	movl	$Idtr, %eax
+	movw	$(640 - 1), (%eax)
+	movl	%ebx, 2(%eax)
+
+	/* 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)
@@ -186,14 +193,7 @@ idt:
 	idte(xx); idte(xx); idte(xx);  idte(xx); idte(xx); idte(xx)
 	idte(xx); idte(xx); idte(xx);  idte(xx); idte(xx); idte(xx)
 	idte(xx) 
-		/* Maskable interrupts (32-255) */
-		/* BIOS entry points (32-63) */
-		/* DOS entry points (64-80) */
-#ifdef __STDC__
-#define idtb(b)	idte(emu##b)
-#else
-#define idtb(b)	idte(emu/**/b)
-#endif
+	/* BIOS entry points (32-63) */
 	idtb(0);  idtb(1);  idtb(2);  idtb(3);  idtb(4);  idtb(5)
 	idtb(6);  idtb(7);  idtb(8);  idtb(9);  idtb(10); idtb(11)
 	idtb(12); idtb(13); idtb(14); idtb(15); idtb(16); idtb(17)
@@ -202,20 +202,37 @@ idt:
 	idtb(30); idtb(31); idtb(32); idtb(33); idtb(34); idtb(35)
 	idtb(36); idtb(37); idtb(38); idtb(39); idtb(40); idtb(41)
 	idtb(42); idtb(43); idtb(44); idtb(45); idtb(46); idtb(47)
+	/* DOS entry points (64-80) */
+
+#undef idtb
 #undef idte
+
+	/* load idtr for interrupts */
+	lidt	Idtr
+	ret
+
+	.bss
+	.align 8, 0x90
+idt:
+	/* IDT has 80 entries at 8 bytes each. */
+	.space  640
+
 	.globl	Idtr
-Idtr:	.word	. - idt - 1
-	.long	idt
+Idtr:	.word	0  // 640 - 1
+	.long	0  // idt
 	.word	0
 
+	.data
 	.align	8
 	.globl	Idtr_real
-Idtr_real:	.word	1023
-		.long	0
-		.word	0
+Idtr_real:
+	.word	1023
+	.long	0
+	.word	0
 
 	.align	8
-Idtr_reset:	.long	0, 0
+Idtr_reset:
+	.long	0, 0
 
 	.align	8
 gdt:
@@ -255,6 +272,7 @@ Gdtr:	.word	. - gdt - 1
 	.long	gdt
 	.word	0
 
+	.text
 #define IENTRY(name,type) \
 IPROC(name): \
 	pushl	$type ; \