pico-keys-sdk/src/fs/flash.c
Pol Henarejos be03298832
Fix potential crash on delete file.
Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>
2023-03-09 18:16:18 +01:00

185 lines
8.4 KiB
C

/*
* This file is part of the Pico HSM SDK distribution (https://github.com/polhenarejos/pico-hsm-sdk).
* Copyright (c) 2022 Pol Henarejos.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3.
*
* This program 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdint.h>
#include <string.h>
#ifndef ENABLE_EMULATION
#include "pico/stdlib.h"
#include "hardware/flash.h"
#else
#define XIP_BASE 0
#define FLASH_SECTOR_SIZE 4096
#define PICO_FLASH_SIZE_BYTES (8 * 1024 * 1024)
#endif
#include "hsm.h"
#include "file.h"
#include <stdio.h>
/*
* ------------------------------------------------------
* | |
* | next_addr | prev_addr | fid | data (len + payload) |
* | |
* ------------------------------------------------------
*/
#define FLASH_TARGET_OFFSET (PICO_FLASH_SIZE_BYTES >> 1) // DATA starts at the mid of flash
#define FLASH_DATA_HEADER_SIZE (sizeof(uintptr_t) + sizeof(uint32_t))
#define FLASH_PERMANENT_REGION (4 * FLASH_SECTOR_SIZE) // 4 sectors (16kb) of permanent memory
//To avoid possible future allocations, data region starts at the end of flash and goes upwards to the center region
const uintptr_t start_data_pool = (XIP_BASE + FLASH_TARGET_OFFSET);
const uintptr_t end_data_pool = (XIP_BASE + PICO_FLASH_SIZE_BYTES) - FLASH_DATA_HEADER_SIZE -
FLASH_PERMANENT_REGION - FLASH_DATA_HEADER_SIZE - 4; //This is a fixed value. DO NOT CHANGE
const uintptr_t end_rom_pool = (XIP_BASE + PICO_FLASH_SIZE_BYTES) - FLASH_DATA_HEADER_SIZE - 4; //This is a fixed value. DO NOT CHANGE
const uintptr_t start_rom_pool = (XIP_BASE + PICO_FLASH_SIZE_BYTES) - FLASH_DATA_HEADER_SIZE -
FLASH_PERMANENT_REGION; //This is a fixed value. DO NOT CHANGE
extern int flash_program_block(uintptr_t addr, const uint8_t *data, size_t len);
extern int flash_program_halfword(uintptr_t addr, uint16_t data);
extern int flash_program_uintptr(uintptr_t, uintptr_t);
extern uintptr_t flash_read_uintptr(uintptr_t addr);
extern uint16_t flash_read_uint16(uintptr_t addr);
extern uint8_t *flash_read(uintptr_t addr);
extern void low_flash_available();
uintptr_t allocate_free_addr(uint16_t size, bool persistent) {
if (size > FLASH_SECTOR_SIZE) {
return 0x0; //ERROR
}
size_t real_size = size + sizeof(uint16_t) + sizeof(uintptr_t) + sizeof(uint16_t) +
sizeof(uintptr_t); //len+len size+next address+fid+prev_addr size
uintptr_t next_base = 0x0, endp = end_data_pool, startp = start_data_pool;
if (persistent) {
endp = end_rom_pool;
startp = start_rom_pool;
}
for (uintptr_t base = endp; base >= startp; base = next_base) {
uintptr_t addr_alg = base & -FLASH_SECTOR_SIZE; //start address of sector
uintptr_t potential_addr = base - real_size;
next_base = flash_read_uintptr(base);
//printf("nb %x %x %x %x\r\n",base,next_base,addr_alg,potential_addr);
//printf("fid %x\r\n",flash_read_uint16(next_base+sizeof(uintptr_t)));
if (next_base == 0x0) { //we are at the end
//now we check if we fit in the current sector
if (addr_alg <= potential_addr) { //it fits in the current sector
flash_program_uintptr(potential_addr, 0x0);
flash_program_uintptr(potential_addr + sizeof(uintptr_t), base);
flash_program_uintptr(base, potential_addr);
return potential_addr;
}
else if (addr_alg - FLASH_SECTOR_SIZE >= startp) { //check whether it fits in the next sector, so we take addr_aligned as the base
potential_addr = addr_alg - real_size;
flash_program_uintptr(potential_addr, 0x0);
flash_program_uintptr(potential_addr + sizeof(uintptr_t), base);
flash_program_uintptr(base, potential_addr);
return potential_addr;
}
return 0x0;
}
//we check if |base-(next_addr+size_next_addr)| > |base-potential_addr| only if fid != 1xxx (not size blocked)
else if (addr_alg <= potential_addr &&
base -
(next_base +
flash_read_uint16(next_base + sizeof(uintptr_t) + sizeof(uintptr_t) +
sizeof(uint16_t)) +
2 *
sizeof(uint16_t) + 2 * sizeof(uintptr_t)) > base - potential_addr &&
(flash_read_uint16(next_base + 2 * sizeof(uintptr_t)) & 0x1000) != 0x1000) {
flash_program_uintptr(potential_addr, next_base);
flash_program_uintptr(next_base + sizeof(uintptr_t), potential_addr);
flash_program_uintptr(potential_addr + sizeof(uintptr_t), base);
flash_program_uintptr(base, potential_addr);
return potential_addr;
}
}
return 0x0; //probably never reached
}
int flash_clear_file(file_t *file) {
if (file == NULL || file->data == NULL) {
return CCID_OK;
}
uintptr_t base_addr =
(uintptr_t)(file->data - sizeof(uintptr_t) - sizeof(uint16_t) - sizeof(uintptr_t));
uintptr_t prev_addr = flash_read_uintptr(base_addr + sizeof(uintptr_t));
uintptr_t next_addr = flash_read_uintptr(base_addr);
//printf("nc %lx->%lx %lx->%lx\r\n",prev_addr,flash_read_uintptr(prev_addr),base_addr,next_addr);
flash_program_uintptr(prev_addr, next_addr);
flash_program_halfword((uintptr_t) file->data, 0);
if (next_addr > 0) {
flash_program_uintptr(next_addr + sizeof(uintptr_t), prev_addr);
}
flash_program_uintptr(base_addr, 0);
flash_program_uintptr(base_addr + sizeof(uintptr_t), 0);
file->data = NULL;
//printf("na %lx->%lx\r\n",prev_addr,flash_read_uintptr(prev_addr));
return CCID_OK;
}
int flash_write_data_to_file_offset(file_t *file, const uint8_t *data, uint16_t len,
uint16_t offset) {
if (!file) {
return CCID_ERR_NULL_PARAM;
}
uint16_t size_file_flash = file->data ? flash_read_uint16((uintptr_t) file->data) : 0;
uint8_t *old_data = NULL;
if (offset + len > FLASH_SECTOR_SIZE || offset > size_file_flash) {
return CCID_ERR_NO_MEMORY;
}
if (file->data) { //already in flash
if (offset + len <= size_file_flash) { //it fits, no need to move it
flash_program_halfword((uintptr_t) file->data, offset + len);
if (data) {
flash_program_block((uintptr_t) file->data + sizeof(uint16_t) + offset, data, len);
}
return CCID_OK;
}
else { //we clear the old file
flash_clear_file(file);
if (offset > 0) {
old_data = (uint8_t *) calloc(1, offset + len);
memcpy(old_data, flash_read((uintptr_t) (file->data + sizeof(uint16_t))), offset);
memcpy(old_data + offset, data, len);
len = offset + len;
data = old_data;
}
}
}
uintptr_t new_addr = allocate_free_addr(len, (file->type & FILE_PERSISTENT) == FILE_PERSISTENT);
//printf("na %x\r\n",new_addr);
if (new_addr == 0x0) {
return CCID_ERR_NO_MEMORY;
}
file->data = (uint8_t *) new_addr + sizeof(uintptr_t) + sizeof(uint16_t) + sizeof(uintptr_t); //next addr+fid+prev addr
flash_program_halfword(new_addr + sizeof(uintptr_t) + sizeof(uintptr_t), file->fid);
flash_program_halfword((uintptr_t) file->data, len);
if (data) {
flash_program_block((uintptr_t) file->data + sizeof(uint16_t), data, len);
}
if (old_data) {
free(old_data);
}
return CCID_OK;
}
int flash_write_data_to_file(file_t *file, const uint8_t *data, uint16_t len) {
return flash_write_data_to_file_offset(file, data, len, 0);
}