/* * 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 "supervise.h" #include <libopencm3/stm32/flash.h> #include <stdint.h> #if !EMULATOR #include <vendor/libopencm3/include/libopencmsis/core_cm3.h> #endif #include "memory.h" #if !EMULATOR static void svhandler_flash_unlock(void) { flash_wait_for_last_operation(); 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 storage sectors 2 and 3. */ if (sector < FLASH_STORAGE_SECTOR_FIRST || sector > FLASH_STORAGE_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; } static void __attribute__((noreturn)) svhandler_reboot_to_bootloader(void) { *STAY_IN_BOOTLOADER_FLAG_ADDR = STAY_IN_BOOTLOADER_FLAG; scb_reset_system(); } 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; case SVC_REBOOT_TO_BOOTLOADER: svhandler_reboot_to_bootloader(); break; default: stack[0] = 0xffffffff; break; } } #endif