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trezor-firmware/legacy/intermediate_fw/trezor.c
Pavol Rusnak 8531b35280
fix(legacy/intermediate_fw): don't erase the whole firmware sector (#1626)
Co-authored-by: Andrew Kozlik <42678794+andrewkozlik@users.noreply.github.com>
2021-05-22 12:15:56 +02:00

155 lines
4.7 KiB
C

/*
* This file is part of the Trezor project, https://trezor.io/
*
* Copyright (C) 2014 Pavol Rusnak <stick@satoshilabs.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 "trezor.h"
#include <libopencm3/stm32/desig.h>
#include <libopencm3/stm32/flash.h>
#include <string.h>
#include <vendor/libopencm3/include/libopencmsis/core_cm3.h>
#include "bitmaps.h"
#include "bl_check.h"
#include "layout.h"
#include "memory.h"
#include "memzero.h"
#include "norcow_config.h"
#include "oled.h"
#include "rng.h"
#include "setup.h"
#include "supervise.h"
#include "timer.h"
#include "util.h"
// legacy storage magic
#define LEGACY_STORAGE_SECTOR 2
static const uint32_t META_MAGIC_V10 = 0x525a5254; // 'TRZR'
// norcow storage magic
static const uint32_t NORCOW_MAGIC = 0x3243524e; // 'NRC2'
static const uint8_t norcow_sectors[NORCOW_SECTOR_COUNT] = NORCOW_SECTORS;
/** Flash program word operation extracted from libopencm3,
* so it can run from RAM
*/
static void __attribute__((noinline, section(".data")))
_flash_program_word(uint32_t address, uint32_t data) {
// Wait for flash controller to be ready
while ((FLASH_SR & FLASH_SR_BSY) == FLASH_SR_BSY)
;
// Set program word width
FLASH_CR &= ~(FLASH_CR_PROGRAM_MASK << FLASH_CR_PROGRAM_SHIFT);
FLASH_CR |= FLASH_CR_PROGRAM_X32 << FLASH_CR_PROGRAM_SHIFT;
// Enable writes to flash
FLASH_CR |= FLASH_CR_PG;
// Program the word
MMIO32(address) = data;
// Wait for flash controller to be ready
while ((FLASH_SR & FLASH_SR_BSY) == FLASH_SR_BSY)
;
// Disable writes to flash
FLASH_CR &= ~FLASH_CR_PG;
}
static void __attribute__((noinline, section(".data")))
invalidate_firmware(void) {
// Flash unlock
FLASH_KEYR = FLASH_KEYR_KEY1;
FLASH_KEYR = FLASH_KEYR_KEY2;
// Erase the first firmware word
// (we don't need full erasure, this speeds up the whole process)
_flash_program_word(FLASH_FWHEADER_START, 0);
// Flash lock
FLASH_CR |= FLASH_CR_LOCK;
}
void __attribute__((noinline, noreturn, section(".data"))) reboot_device(void) {
__disable_irq();
*STAY_IN_BOOTLOADER_FLAG_ADDR = STAY_IN_BOOTLOADER_FLAG;
SCB_AIRCR = SCB_AIRCR_VECTKEY | SCB_AIRCR_SYSRESETREQ;
while (1)
;
}
/** Entry point of RAM shim that deletes old FW, storage and reboot */
void __attribute__((noinline, noreturn, section(".data")))
invalidate_firmware_and_reboot(void) {
invalidate_firmware();
reboot_device();
for (;;)
; // never reached, but compiler would generate error
}
int main(void) {
setupApp();
__stack_chk_guard = random32(); // this supports compiler provided
// unpredictable stack protection checks
oledInit();
if (is_mode_unprivileged()) {
layoutDialog(&bmp_icon_warning, NULL, NULL, NULL, "Cannot update", NULL,
NULL, "Unprivileged mode", "Unsigned firmware", NULL);
shutdown();
}
mpu_config_off(); // needed for flash writable, RAM RWX
timer_init();
check_and_replace_bootloader(false);
secbool storage_initialized = secfalse;
// check legacy storage
uint32_t *magic = (uint32_t *)flash_get_address(LEGACY_STORAGE_SECTOR, 0,
sizeof(META_MAGIC_V10));
if (*magic == META_MAGIC_V10) {
storage_initialized = sectrue;
}
if (storage_initialized == secfalse) {
// check norcow storage
for (uint8_t i = 0; i < NORCOW_SECTOR_COUNT; i++) {
magic = (uint32_t *)flash_get_address(norcow_sectors[i], 0,
sizeof(NORCOW_MAGIC));
if (*magic == NORCOW_MAGIC) {
storage_initialized = sectrue;
break;
}
}
}
if (sectrue == storage_initialized) {
// Storage probably contains a seed so leave the firmware intact.
// Invalidating it would cause the bootloader to wipe the storage before
// installing the target firmware. User will need to confirm installation.
reboot_device();
} else {
// New device. Invalidate the intermediate firmware so that after reboot
// the bootloader will install the target firmware without asking for user
// confirmation.
invalidate_firmware_and_reboot();
}
return 0;
}