libpayload: x86: Add support for catching processor exceptions.

This functionality is already available for ARM, so lets add it to x86 as
well. We'll want to be able to hook exceptions when running as a remote GDB
target.

Change-Id: I42f640b08eb9eb86a1bcab3c327f7780191a2eb5
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: https://chromium-review.googlesource.com/179601
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
Commit-Queue: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit 5b8cf0c9f70a7e14766a2b095e6739a8d6321a34)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6898
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>

1 files changed, 199 insertions, 0 deletions

diff --git a/payloads/libpayload/arch/x86/exception.c b/payloads/libpayload/arch/x86/exception.c
new file mode 100644
index 0000000000..a9a65ca5a2
--- /dev/null
+++ b/payloads/libpayload/arch/x86/exception.c
@@ -0,0 +1,199 @@
+/*
+ * This file is part of the libpayload project.
+ *
+ * Copyright 2013 Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <exception.h>
+#include <libpayload.h>
+#include <stdint.h>
+
+uint8_t exception_stack[0x1000] __attribute__((aligned(8)));
+extern void *exception_stack_end;
+
+struct exception_state
+{
+	u32 eax;
+	u32 ecx;
+	u32 edx;
+	u32 ebx;
+	u32 esp;
+	u32 ebp;
+	u32 esi;
+	u32 edi;
+	u32 eip;
+	u32 eflags;
+	u32 cs;
+	u32 ss;
+	u32 ds;
+	u32 es;
+	u32 fs;
+	u32 gs;
+	u32 error_code;
+	u32 vector;
+} __attribute__((packed));
+
+struct exception_info
+{
+	const char *name;
+	void (*error_code_printer)(u32 code);
+};
+
+static void print_segment_error_code(u32 code)
+{
+	printf("%#x - descriptor %#x in the ", code, (code >> 3) & 0x1f);
+	if (code & (0x1 << 1)) {
+		printf("IDT");
+	} else {
+		if (code & 0x04)
+			printf("LDT");
+		else
+			printf("GDT");
+	}
+	if (code & (0x1 << 0))
+		printf(", external to the CPU");
+	else
+		printf(", internal to the CPU");
+}
+
+static void print_page_fault_error_code(u32 code)
+{
+	printf("%#x -", code);
+	if (code & (0x1 << 0))
+		printf(" page protection");
+	else
+		printf(" page not present");
+	if (code & (0x1 << 1))
+		printf(", write");
+	else
+		printf(", read");
+	if (code & (0x1 << 2))
+		printf(", user");
+	else
+		printf(", supervisor");
+	if (code & (0x1 << 3))
+		printf(", reserved bits set");
+	if (code & (0x1 << 4))
+		printf(", instruction fetch");
+}
+
+static void print_raw_error_code(u32 code)
+{
+	printf("%#x", code);
+}
+
+static struct exception_info exceptions[] = {
+	[0] =  { .name = "divide by zero" },
+	[1] =  { .name = "debug" },
+	[2] =  { .name = "non-maskable-interrupt" },
+	[3] =  { .name = "breakpoint" },
+	[4] =  { .name = "overflow" },
+	[5] =  { .name = "bound range" },
+	[6] =  { .name = "invalid opcode" },
+	[7] =  { .name = "device not available" },
+	[8] =  { .name = "double fault",
+		 .error_code_printer = &print_raw_error_code },
+	[10] = { .name = "invalid tss",
+		 .error_code_printer = &print_segment_error_code },
+	[11] = { .name = "segment not present",
+		 .error_code_printer = &print_segment_error_code },
+	[12] = { .name = "stack",
+		 .error_code_printer = &print_segment_error_code },
+	[13] = { .name = "general protection",
+		 .error_code_printer = &print_segment_error_code },
+	[14] = { .name = "page fault",
+		 .error_code_printer = &print_page_fault_error_code },
+	[16] = { .name = "x87 floating point" },
+	[17] = { .name = "alignment check",
+		 .error_code_printer = &print_raw_error_code },
+	[18] = { .name = "machine check" },
+	[19] = { .name = "SIMD floating point" },
+	[30] = { .name = "security",
+		 .error_code_printer = &print_raw_error_code },
+};
+
+static void dump_stack(uintptr_t addr, size_t bytes)
+{
+	int i, j;
+	const int line = 8;
+	uint32_t *ptr = (uint32_t *)(addr & ~(line * sizeof(*ptr) - 1));
+
+	printf("Dumping stack:\n");
+	for (i = bytes / sizeof(*ptr); i >= 0; i -= line) {
+		printf("%p: ", ptr + i);
+		for (j = i; j < i + line; j++)
+			printf("%08x ", *(ptr + j));
+		printf("\n");
+	}
+}
+
+void exception_handler(void);
+void exception_handler(void)
+{
+	struct exception_state *state =
+		(void *)((u8 *)exception_stack_end - sizeof(*state));
+
+	struct exception_info *info = NULL;
+	if (state->vector < ARRAY_SIZE(exceptions))
+		info = &exceptions[state->vector];
+
+	if (info)
+		printf("Exception %d (%s)\n", state->vector, info->name);
+	else
+		printf("Unrecognized exception %d\n", state->vector);
+	if (info->error_code_printer) {
+		printf("Error code: ");
+		info->error_code_printer(state->error_code);
+		printf("\n");
+	}
+	printf("EIP:    0x%08x\n", state->eip);
+	printf("CS:     0x%04x\n", state->cs);
+	printf("EFLAGS: 0x%08x\n", state->eflags);
+	printf("EAX:    0x%08x\n", state->eax);
+	printf("ECX:    0x%08x\n", state->ecx);
+	printf("EDX:    0x%08x\n", state->edx);
+	printf("EBX:    0x%08x\n", state->ebx);
+	printf("ESP:    0x%08x\n", state->esp);
+	printf("EBP:    0x%08x\n", state->ebp);
+	printf("ESI:    0x%08x\n", state->esi);
+	printf("EDI:    0x%08x\n", state->edi);
+	printf("DS:     0x%04x\n", state->ds);
+	printf("ES:     0x%04x\n", state->es);
+	printf("SS:     0x%04x\n", state->ss);
+	printf("FS:     0x%04x\n", state->fs);
+	printf("GS:     0x%04x\n", state->gs);
+
+	dump_stack(state->esp, 512);
+
+	halt();
+}
+
+void exception_init_asm(void);
+void exception_init(void)
+{
+	exception_stack_end = exception_stack + sizeof(exception_stack);
+	exception_init_asm();
+}