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/*
* 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 <arch/exception.h>
#include <libpayload.h>
#include <stdint.h>
void exception_test(void);
static int test_abort;
void exception_undefined_instruction(uint32_t *);
void exception_software_interrupt(uint32_t *);
void exception_prefetch_abort(uint32_t *);
void exception_data_abort(uint32_t *);
void exception_not_used(uint32_t *);
void exception_irq(uint32_t *);
void exception_fiq(uint32_t *);
static void print_regs(uint32_t *regs)
{
/* Don't print the link register and stack pointer since we don't have their
* actual value. They are hidden by the 'shadow' registers provided
* by the trap hardware.
*/
for (int i = 0; i < 16; i++) {
if (i == 15)
printf("PC");
else if (i == 14)
continue; /* LR */
else if (i == 13)
continue; /* SP */
else if (i == 12)
printf("IP");
else
printf("R%d", i);
printf(" = 0x%08x\n", regs[i]);
}
}
void exception_undefined_instruction(uint32_t *regs)
{
printf("exception _undefined_instruction\n");
print_regs(regs);
halt();
}
void exception_software_interrupt(uint32_t *regs)
{
printf("exception _software_interrupt\n");
print_regs(regs);
halt();
}
void exception_prefetch_abort(uint32_t *regs)
{
printf("exception _prefetch_abort\n");
print_regs(regs);
halt();
}
void exception_data_abort(uint32_t *regs)
{
if (test_abort) {
regs[15] = regs[0];
return;
} else {
printf("exception _data_abort\n");
print_regs(regs);
}
halt();
}
void exception_not_used(uint32_t *regs)
{
printf("exception _not_used\n");
print_regs(regs);
halt();
}
void exception_irq(uint32_t *regs)
{
printf("exception _irq\n");
print_regs(regs);
halt();
}
void exception_fiq(uint32_t *regs)
{
printf("exception _fiq\n");
print_regs(regs);
halt();
}
static inline uint32_t get_sctlr(void)
{
uint32_t val;
asm("mrc p15, 0, %0, c1, c0, 0" : "=r" (val));
return val;
}
static inline void set_sctlr(uint32_t val)
{
asm volatile("mcr p15, 0, %0, c1, c0, 0" :: "r" (val));
asm volatile("" ::: "memory");
}
void exception_init(void)
{
static const uint32_t sctlr_te = (0x1 << 30);
static const uint32_t sctlr_v = (0x1 << 13);
static const uint32_t sctlr_a = (0x1 << 1);
uint32_t sctlr = get_sctlr();
/* Handle exceptions in ARM mode. */
sctlr &= ~sctlr_te;
/* Set V=0 in SCTLR so VBAR points to the exception vector table. */
sctlr &= ~sctlr_v;
/* Enforce alignment. */
sctlr |= sctlr_a;
set_sctlr(sctlr);
extern uint32_t exception_table[];
set_vbar((uintptr_t)exception_table);
test_abort = 1;
exception_test();
test_abort = 0;
}
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