arch/x86: prepare for having an idt in other stages

Currently the idt setup and handling is only in ramstage. In
order to prepare having an exception handler in other stages
move the interrupt vector entry code to its own compilation
unit. vec0 and int_hand need to be global so c_start.S
references will resolve at link time.

BUG=b:72728953

Change-Id: I435b96d987d69fb41ea27a73e2dd634b5d6ee3d9
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/25760
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

3 files changed, 192 insertions, 171 deletions

diff --git a/src/arch/x86/Makefile.inc b/src/arch/x86/Makefile.inc
index cc529b29cd..b8cf3a6493 100644
--- a/src/arch/x86/Makefile.inc
+++ b/src/arch/x86/Makefile.inc
@@ -323,6 +323,7 @@ ramstage-y += cpu.c
 ramstage-y += cpu_common.c
 ramstage-y += ebda.c
 ramstage-y += exception.c
+ramstage-y += idt.S
 ramstage-y += gdt.c
 ramstage-$(CONFIG_IOAPIC) += ioapic.c
 ramstage-y += memcpy.c
diff --git a/src/arch/x86/c_start.S b/src/arch/x86/c_start.S
index 97e2b5adc4..6cea5c3167 100644
--- a/src/arch/x86/c_start.S
+++ b/src/arch/x86/c_start.S
@@ -123,177 +123,6 @@ _start:
 	hlt
 	jmp	.Lhlt
 
-vec0:
-	push	$0 /* error code */
-	push	$0 /* vector */
-	jmp int_hand
-vec1:
-	push	$0 /* error code */
-	push	$1 /* vector */
-	jmp int_hand
-
-vec2:
-	push	$0 /* error code */
-	push	$2 /* vector */
-	jmp int_hand
-
-vec3:
-	push	$0 /* error code */
-	push	$3 /* vector */
-	jmp	int_hand
-
-vec4:
-	push	$0 /* error code */
-	push	$4 /* vector */
-	jmp	int_hand
-
-vec5:
-	push	$0 /* error code */
-	push	$5 /* vector */
-	jmp	int_hand
-
-vec6:
-	push	$0 /* error code */
-	push	$6 /* vector */
-	jmp	int_hand
-
-vec7:
-	push	$0 /* error code */
-	push	$7 /* vector */
-	jmp	int_hand
-
-vec8:
-	/* error code */
-	push	$8 /* vector */
-	jmp	int_hand
-	.word	0x9090
-
-vec9:
-	push	$0 /* error code */
-	push	$9 /* vector */
-	jmp int_hand
-
-vec10:
-	/* error code */
-	push	$10 /* vector */
-	jmp	int_hand
-	.word	0x9090
-
-vec11:
-	/* error code */
-	push	$11 /* vector */
-	jmp	int_hand
-	.word	0x9090
-
-vec12:
-	/* error code */
-	push	$12 /* vector */
-	jmp	int_hand
-	.word	0x9090
-
-vec13:
-	/* error code */
-	push	$13 /* vector */
-	jmp	int_hand
-	.word	0x9090
-
-vec14:
-	/* error code */
-	push	$14 /* vector */
-	jmp	int_hand
-	.word	0x9090
-
-vec15:
-	push	$0 /* error code */
-	push	$15 /* vector */
-	jmp	int_hand
-
-vec16:
-	push	$0 /* error code */
-	push	$16 /* vector */
-	jmp	int_hand
-
-vec17:
-	/* error code */
-	push	$17 /* vector */
-	jmp	int_hand
-	.word	0x9090
-
-vec18:
-	push	$0 /* error code */
-	push	$18 /* vector */
-	jmp	int_hand
-
-vec19:
-	push	$0 /* error code */
-	push	$19 /* vector */
-	jmp	int_hand
-
-int_hand:
-	/* At this point, on x86-32, on the stack there is:
-	 *  0(%esp) vector
-	 *  4(%esp) error code
-	 *  8(%esp) eip
-	 * 12(%esp) cs
-	 * 16(%esp) eflags
-	 */
-#ifdef __x86_64__
-	push	%rdi
-	push	%rsi
-	push	%rbp
-	/* Original stack pointer */
-	lea	32(%rsp), %rbp
-	push	%rbp
-	push	%rbx
-	push	%rdx
-	push	%rcx
-	push	%rax
-
-	push	%rsp	/* Pointer to structure on the stack */
-	call	x86_exception
-	pop	%rax	/* Drop the pointer */
-
-	pop	%rax
-	pop	%rcx
-	pop	%rdx
-	pop	%rbx
-	pop	%rbp	/* Ignore saved %rsp value */
-	pop	%rbp
-	pop	%rsi
-	pop	%rdi
-
-	add	$8, %rsp /* pop of the vector and error code */
-#else
-	pushl	%edi
-	pushl	%esi
-	pushl	%ebp
-
-	/* Original stack pointer */
-	leal	32(%esp), %ebp
-	pushl	%ebp
-	pushl	%ebx
-	pushl	%edx
-	pushl	%ecx
-	pushl	%eax
-
-	pushl	%esp	/* Pointer to structure on the stack */
-	call	x86_exception
-	pop	%eax	/* Drop the pointer */
-
-	popl	%eax
-	popl	%ecx
-	popl	%edx
-	popl	%ebx
-	popl	%ebp	/* Ignore saved %esp value */
-	popl	%ebp
-	popl	%esi
-	popl	%edi
-
-	addl	$8, %esp /* pop of the vector and error code */
-#endif
-
-	iret
-
 #if IS_ENABLED(CONFIG_GDB_WAIT)
 
 	.globl gdb_stub_breakpoint
diff --git a/src/arch/x86/idt.S b/src/arch/x86/idt.S
new file mode 100644
index 0000000000..1878f802ed
--- /dev/null
+++ b/src/arch/x86/idt.S
@@ -0,0 +1,191 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+	.section ".text._idt", "ax", @progbits
+#ifdef __x86_64__
+	.code64
+#else
+	.code32
+#endif
+.global vec0
+vec0:
+	push	$0 /* error code */
+	push	$0 /* vector */
+	jmp int_hand
+vec1:
+	push	$0 /* error code */
+	push	$1 /* vector */
+	jmp int_hand
+
+vec2:
+	push	$0 /* error code */
+	push	$2 /* vector */
+	jmp int_hand
+
+vec3:
+	push	$0 /* error code */
+	push	$3 /* vector */
+	jmp	int_hand
+
+vec4:
+	push	$0 /* error code */
+	push	$4 /* vector */
+	jmp	int_hand
+
+vec5:
+	push	$0 /* error code */
+	push	$5 /* vector */
+	jmp	int_hand
+
+vec6:
+	push	$0 /* error code */
+	push	$6 /* vector */
+	jmp	int_hand
+
+vec7:
+	push	$0 /* error code */
+	push	$7 /* vector */
+	jmp	int_hand
+
+vec8:
+	/* error code */
+	push	$8 /* vector */
+	jmp	int_hand
+	.word	0x9090
+
+vec9:
+	push	$0 /* error code */
+	push	$9 /* vector */
+	jmp int_hand
+
+vec10:
+	/* error code */
+	push	$10 /* vector */
+	jmp	int_hand
+	.word	0x9090
+
+vec11:
+	/* error code */
+	push	$11 /* vector */
+	jmp	int_hand
+	.word	0x9090
+
+vec12:
+	/* error code */
+	push	$12 /* vector */
+	jmp	int_hand
+	.word	0x9090
+
+vec13:
+	/* error code */
+	push	$13 /* vector */
+	jmp	int_hand
+	.word	0x9090
+
+vec14:
+	/* error code */
+	push	$14 /* vector */
+	jmp	int_hand
+	.word	0x9090
+
+vec15:
+	push	$0 /* error code */
+	push	$15 /* vector */
+	jmp	int_hand
+
+vec16:
+	push	$0 /* error code */
+	push	$16 /* vector */
+	jmp	int_hand
+
+vec17:
+	/* error code */
+	push	$17 /* vector */
+	jmp	int_hand
+	.word	0x9090
+
+vec18:
+	push	$0 /* error code */
+	push	$18 /* vector */
+	jmp	int_hand
+
+vec19:
+	push	$0 /* error code */
+	push	$19 /* vector */
+	jmp	int_hand
+
+.global int_hand
+int_hand:
+	/* At this point, on x86-32, on the stack there is:
+	 *  0(%esp) vector
+	 *  4(%esp) error code
+	 *  8(%esp) eip
+	 * 12(%esp) cs
+	 * 16(%esp) eflags
+	 */
+#ifdef __x86_64__
+	push	%rdi
+	push	%rsi
+	push	%rbp
+	/* Original stack pointer */
+	lea	32(%rsp), %rbp
+	push	%rbp
+	push	%rbx
+	push	%rdx
+	push	%rcx
+	push	%rax
+
+	push	%rsp	/* Pointer to structure on the stack */
+	call	x86_exception
+	pop	%rax	/* Drop the pointer */
+
+	pop	%rax
+	pop	%rcx
+	pop	%rdx
+	pop	%rbx
+	pop	%rbp	/* Ignore saved %rsp value */
+	pop	%rbp
+	pop	%rsi
+	pop	%rdi
+
+	add	$8, %rsp /* pop of the vector and error code */
+#else
+	pushl	%edi
+	pushl	%esi
+	pushl	%ebp
+
+	/* Original stack pointer */
+	leal	32(%esp), %ebp
+	pushl	%ebp
+	pushl	%ebx
+	pushl	%edx
+	pushl	%ecx
+	pushl	%eax
+
+	pushl	%esp	/* Pointer to structure on the stack */
+	call	x86_exception
+	pop	%eax	/* Drop the pointer */
+
+	popl	%eax
+	popl	%ecx
+	popl	%edx
+	popl	%ebx
+	popl	%ebp	/* Ignore saved %esp value */
+	popl	%ebp
+	popl	%esi
+	popl	%edi
+
+	addl	$8, %esp /* pop of the vector and error code */
+#endif
+
+	iret