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Implement cache-based reads

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This commit is contained in:
Lucian Copeland 2020-04-13 15:14:38 -04:00
parent 426d2afe28
commit 83a55f65a4
1 changed files with 21 additions and 6 deletions
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27
ports/stm/supervisor/internal_flash.c
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@ -234,7 +234,7 @@ void supervisor_flash_flush(void) {
}
}
static int32_t convert_block_to_flash_addr(uint32_t block) {
static uint32_t convert_block_to_flash_addr(uint32_t block) {
if (0 <= block && block < INTERNAL_FLASH_FILESYSTEM_NUM_BLOCKS) {
// a block in partition 1
return INTERNAL_FLASH_FILESYSTEM_START_ADDR + block * FILESYSTEM_BLOCK_SIZE;
@ -244,15 +244,30 @@ static int32_t convert_block_to_flash_addr(uint32_t block) {
}
mp_uint_t supervisor_flash_read_blocks(uint8_t *dest, uint32_t block, uint32_t num_blocks) {
// Must write out anything in cache before trying to read.
supervisor_flash_flush();
int32_t src = convert_block_to_flash_addr(block);
if (src == -1) {
// bad block number
return false;
}
memcpy(dest, (uint8_t*) src, FILESYSTEM_BLOCK_SIZE*num_blocks);
// Determine whether the read is contained within the sector
uint32_t sector_size;
uint32_t sector_start_addr;
flash_get_sector_info(src, &sector_start_addr, &sector_size);
// Count how many blocks are left in the sector
uint32_t count = (sector_size - (src - sector_start_addr))/FILESYSTEM_BLOCK_SIZE;
count = MIN(num_blocks, count);
if (count < num_blocks && _cache_flash_addr == sector_start_addr) {
// Read is contained in the cache, so just read cache
memcpy(dest, (_flash_cache + (src-sector_start_addr)), FILESYSTEM_BLOCK_SIZE*num_blocks);
} else {
// The read spans multiple sectors or is in another sector
// Must write out anything in cache before trying to read.
supervisor_flash_flush();
memcpy(dest, (uint8_t*) src, FILESYSTEM_BLOCK_SIZE*num_blocks);
}
return 0; // success
}
@ -271,7 +286,7 @@ mp_uint_t supervisor_flash_write_blocks(const uint8_t *src, uint32_t block_num,
uint32_t sector_start_addr;
flash_get_sector_info(dest, &sector_start_addr, &sector_size);
// Fail for any sector outside the 16k ones for now
// Fail for any sector outside what's supported by the cache
if (sector_size > sizeof(_flash_cache)) {
reset_into_safe_mode(FLASH_WRITE_FAIL);
}