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/* Copyright 2014 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "common.h"
#include "console.h"
#include "cpu.h"
#include "host_command.h"
#include "panic.h"
#include "panic-internal.h"
#include "printf.h"
#include "system.h"
#include "task.h"
#include "timer.h"
#include "util.h"
#include "watchdog.h"
/* Whether bus fault is ignored */
static int bus_fault_ignored;
/* Panic data goes at the end of RAM. */
static struct panic_data *const pdata_ptr = PANIC_DATA_PTR;
/* Preceded by stack, rounded down to nearest 64-bit-aligned boundary */
static const uint32_t pstack_addr = ((uint32_t)pdata_ptr) & ~7;
/**
* Print the name and value of a register
*
* This is a convenient helper function for displaying a register value.
* It shows the register name in a 3 character field, followed by a colon.
* The register value is regs[index], and this is shown in hex. If regs is
* NULL, then we display spaces instead.
*
* After displaying the value, either a space or \n is displayed depending
* on the register number, so that (assuming the caller passes all 16
* registers in sequence) we put 4 values per line like this
*
* r0 :0000000b r1 :00000047 r2 :60000000 r3 :200012b5
* r4 :00000000 r5 :08004e64 r6 :08004e1c r7 :200012a8
* r8 :08004e64 r9 :00000002 r10:00000000 r11:00000000
* r12:0000003f sp :200009a0 lr :0800270d pc :0800351a
*
* @param regnum Register number to display (0-15)
* @param regs Pointer to array holding the registers, or NULL
* @param index Index into array where the register value is present
*/
static void print_reg(int regnum, const uint32_t *regs, int index)
{
static const char regname[] = "r10r11r12sp lr pc ";
static char rname[3] = "r ";
const char *name;
rname[1] = '0' + regnum;
name = regnum < 10 ? rname : ®name[(regnum - 10) * 3];
panic_printf("%c%c%c:", name[0], name[1], name[2]);
if (regs)
panic_printf("%08x", regs[index]);
else
panic_puts(" ");
panic_puts((regnum & 3) == 3 ? "\n" : " ");
}
/*
* Returns non-zero if the exception frame was created on the main stack, or
* zero if it's on the process stack.
*
* See B1.5.8 "Exception return behavior" of ARM DDI 0403D for details.
*/
static int32_t is_frame_in_handler_stack(const uint32_t exc_return)
{
return (exc_return & 0xf) == 1 || (exc_return & 0xf) == 9;
}
/*
* Print panic data
*/
void panic_data_print(const struct panic_data *pdata)
{
const uint32_t *lregs = pdata->cm.regs;
const uint32_t *sregs = NULL;
const int32_t in_handler = is_frame_in_handler_stack(
pdata->cm.regs[CORTEX_PANIC_REGISTER_LR]);
int i;
if (pdata->flags & PANIC_DATA_FLAG_FRAME_VALID)
sregs = pdata->cm.frame;
panic_printf("\n=== %s EXCEPTION: %02x ====== xPSR: %08x ===\n",
in_handler ? "HANDLER" : "PROCESS",
lregs[CORTEX_PANIC_REGISTER_IPSR] & 0xff,
sregs ? sregs[CORTEX_PANIC_FRAME_REGISTER_PSR] : -1);
for (i = 0; i < 4; i++)
print_reg(i, sregs, i);
for (i = 4; i < 10; i++)
print_reg(i, lregs, i - 1);
print_reg(10, lregs, CORTEX_PANIC_REGISTER_R10);
print_reg(11, lregs, CORTEX_PANIC_REGISTER_R11);
print_reg(12, sregs, CORTEX_PANIC_FRAME_REGISTER_R12);
print_reg(13, lregs,
in_handler ? CORTEX_PANIC_REGISTER_MSP :
CORTEX_PANIC_REGISTER_PSP);
print_reg(14, sregs, CORTEX_PANIC_FRAME_REGISTER_LR);
print_reg(15, sregs, CORTEX_PANIC_FRAME_REGISTER_PC);
}
void __keep report_panic(void)
{
/*
* Don't need to get pointer via get_panic_data_write()
* because memory below pdata_ptr is stack now (see exception_panic())
*/
struct panic_data *pdata = pdata_ptr;
uint32_t sp;
pdata->magic = PANIC_DATA_MAGIC;
pdata->struct_size = sizeof(*pdata);
pdata->struct_version = 2;
pdata->arch = PANIC_ARCH_CORTEX_M;
pdata->flags = 0;
pdata->reserved = 0;
/* Choose the right sp (psp or msp) based on EXC_RETURN value */
sp = is_frame_in_handler_stack(
pdata->cm.regs[CORTEX_PANIC_REGISTER_LR]) ?
pdata->cm.regs[CORTEX_PANIC_REGISTER_MSP] :
pdata->cm.regs[CORTEX_PANIC_REGISTER_PSP];
/* If stack is valid, copy exception frame to pdata */
if ((sp & 3) == 0 && sp >= CONFIG_RAM_BASE &&
sp <= CONFIG_RAM_BASE + CONFIG_RAM_SIZE - 8 * sizeof(uint32_t)) {
const uint32_t *sregs = (const uint32_t *)sp;
int i;
for (i = 0; i < 8; i++)
pdata->cm.frame[i] = sregs[i];
pdata->flags |= PANIC_DATA_FLAG_FRAME_VALID;
}
panic_data_print(pdata);
panic_reboot();
}
/**
* Default exception handler, which reports a panic.
*
* Declare this as a naked call so we can extract raw LR and IPSR values.
*/
void exception_panic(void)
{
/* Save registers and branch directly to panic handler */
asm volatile(
"mrs r1, psp\n"
"mrs r2, ipsr\n"
"mov r3, sp\n"
"stmia %[pregs]!, {r1-r7}\n"
"mov r1, r8\n"
"mov r2, r9\n"
"mov r3, r10\n"
"mov r4, r11\n"
"mov r5, lr\n"
"stmia %[pregs]!, {r1-r5}\n"
"mov sp, %[pstack]\n"
"bl report_panic\n"
:
: [pregs] "r"(pdata_ptr->cm.regs), [pstack] "r"(pstack_addr)
:
/* Constraints protecting these from being clobbered.
* Gcc should be using r0 & r12 for pregs and pstack. */
"r1", "r2", "r3", "r4", "r5", "r6",
/* clang warns that we're clobbering a reserved register:
* inline asm clobber list contains reserved registers: R7
* [-Werror,-Winline-asm]. The intent of the clobber list is
* to force pregs and pstack to be in R0 and R12, which
* still holds.
*/
#ifndef __clang__
"r7",
#endif
"r8", "r9", "r10", "r11", "cc", "memory");
}
#ifdef CONFIG_SOFTWARE_PANIC
void software_panic(uint32_t reason, uint32_t info)
{
__asm__("mov " STRINGIFY(
SOFTWARE_PANIC_INFO_REG) ", %0\n"
"mov " STRINGIFY(
SOFTWARE_PANIC_REASON_REG) ", %1\n"
"bl exception_panic\n"
:
: "r"(info), "r"(reason));
__builtin_unreachable();
}
void panic_set_reason(uint32_t reason, uint32_t info, uint8_t exception)
{
struct panic_data *const pdata = get_panic_data_write();
uint32_t *lregs;
lregs = pdata->cm.regs;
/* Setup panic data structure */
memset(pdata, 0, CONFIG_PANIC_DATA_SIZE);
pdata->magic = PANIC_DATA_MAGIC;
pdata->struct_size = CONFIG_PANIC_DATA_SIZE;
pdata->struct_version = 2;
pdata->arch = PANIC_ARCH_CORTEX_M;
/* Log panic cause */
lregs[CORTEX_PANIC_REGISTER_IPSR] = exception;
lregs[CORTEX_PANIC_REGISTER_R4] = reason;
lregs[CORTEX_PANIC_REGISTER_R5] = info;
}
void panic_get_reason(uint32_t *reason, uint32_t *info, uint8_t *exception)
{
struct panic_data *const pdata = panic_get_data();
uint32_t *lregs;
if (pdata && pdata->struct_version == 2) {
lregs = pdata->cm.regs;
*exception = lregs[CORTEX_PANIC_REGISTER_IPSR];
*reason = lregs[CORTEX_PANIC_REGISTER_R4];
*info = lregs[CORTEX_PANIC_REGISTER_R5];
} else {
*exception = *reason = *info = 0;
}
}
#endif
void bus_fault_handler(void)
{
if (!bus_fault_ignored)
exception_panic();
}
void ignore_bus_fault(int ignored)
{
bus_fault_ignored = ignored;
}
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