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trezor-firmware/supervise.c
2018-04-16 14:12:47 +02:00

93 lines
2.5 KiB
C

/*
* This file is part of the TREZOR project, https://trezor.io/
*
* Copyright (C) 2018 Jochen Hoenicke <hoenicke@gmail.com>
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include <libopencm3/stm32/flash.h>
#include <stdint.h>
#include "supervise.h"
#include "memory.h"
#if !EMULATOR
static void svhandler_flash_unlock(void) {
flash_clear_status_flags();
flash_unlock();
}
static void svhandler_flash_program(uint32_t psize) {
/* Wait for any write operation to complete. */
flash_wait_for_last_operation();
/* check program size argument */
if (psize != FLASH_CR_PROGRAM_X8
&& psize != FLASH_CR_PROGRAM_X16
&& psize != FLASH_CR_PROGRAM_X32
&& psize != FLASH_CR_PROGRAM_X64)
return;
FLASH_CR = (FLASH_CR & ~(FLASH_CR_PROGRAM_MASK << FLASH_CR_PROGRAM_SHIFT))
| (psize << FLASH_CR_PROGRAM_SHIFT);
FLASH_CR |= FLASH_CR_PG;
}
static void svhandler_flash_erase_sector(uint16_t sector) {
/* we only allow erasing meta sectors 2 and 3. */
if (sector < FLASH_META_SECTOR_FIRST ||
sector > FLASH_META_SECTOR_LAST) {
return;
}
flash_erase_sector(sector, FLASH_CR_PROGRAM_X32);
}
static uint32_t svhandler_flash_lock(void) {
/* Wait for any write operation to complete. */
flash_wait_for_last_operation();
/* Disable writes to flash. */
FLASH_CR &= ~FLASH_CR_PG;
/* lock flash register */
FLASH_CR |= FLASH_CR_LOCK;
/* return flash status register */
return FLASH_SR;
}
extern volatile uint32_t system_millis;
void svc_handler_main(uint32_t *stack) {
uint8_t svc_number = ((uint8_t*) stack[6])[-2];
switch (svc_number) {
case SVC_FLASH_UNLOCK:
svhandler_flash_unlock();
break;
case SVC_FLASH_PROGRAM:
svhandler_flash_program(stack[0]);
break;
case SVC_FLASH_ERASE:
svhandler_flash_erase_sector(stack[0]);
break;
case SVC_FLASH_LOCK:
stack[0] = svhandler_flash_lock();
break;
case SVC_TIMER_MS:
stack[0] = system_millis;
break;
default:
stack[0] = 0xffffffff;
break;
}
}
#endif