qmk_firmware/drivers/eeprom/eeprom_transient.c

62 lines
1.9 KiB
C

/* Copyright 2019 Nick Brassel (tzarc)
*
* 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, either version 2 of the License, or
* (at your option) any later version.
*
* 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>
#include "eeprom_driver.h"
#include "eeprom_transient.h"
__attribute__((aligned(4))) static uint8_t transientBuffer[TRANSIENT_EEPROM_SIZE] = {0};
size_t clamp_length(intptr_t offset, size_t len) {
if (offset + len > TRANSIENT_EEPROM_SIZE) {
len = TRANSIENT_EEPROM_SIZE - offset;
}
return len;
}
void eeprom_driver_init(void) {}
void eeprom_driver_format(bool erase) {
/* The transient eeprom driver doesn't necessarily need to be formatted before use, and it always starts up filled with zeros, due to placement in the .bss section */
if (erase) {
eeprom_driver_erase();
}
}
void eeprom_driver_erase(void) {
memset(transientBuffer, 0x00, TRANSIENT_EEPROM_SIZE);
}
void eeprom_read_block(void *buf, const void *addr, size_t len) {
intptr_t offset = (intptr_t)addr;
memset(buf, 0x00, len);
len = clamp_length(offset, len);
if (len > 0) {
memcpy(buf, &transientBuffer[offset], len);
}
}
void eeprom_write_block(const void *buf, void *addr, size_t len) {
intptr_t offset = (intptr_t)addr;
len = clamp_length(offset, len);
if (len > 0) {
memcpy(&transientBuffer[offset], buf, len);
}
}