nrf: sqpi_flash: Handle unaligned reads

crypto-aes
Jeff Epler 3 years ago
parent 1b33cd11fc
commit 1e6c08fc30
  1. 43
      ports/nrf/supervisor/qspi_flash.c

@ -83,11 +83,52 @@ bool spi_flash_sector_command(uint8_t command, uint32_t address) {
}
bool spi_flash_write_data(uint32_t address, uint8_t* data, uint32_t length) {
// TODO: In theory, this also needs to handle unaligned data and
// non-multiple-of-4 length. (in practice, I don't think the fat layer
// generates such writes)
return nrfx_qspi_write(data, length, address) == NRFX_SUCCESS;
}
bool spi_flash_read_data(uint32_t address, uint8_t* data, uint32_t length) {
return nrfx_qspi_read(data, length, address) == NRFX_SUCCESS;
int misaligned = ((intptr_t)data) & 3;
// If the data is misaligned, we need to read 4 bytes
// into an aligned buffer, and then copy 1, 2, or 3 bytes from the aligned
// buffer to data.
if(misaligned) {
int sz = 4 - misaligned;
__attribute__((aligned(4))) uint8_t buf[4];
if(nrfx_qspi_read(buf, 4, address) != NRFX_SUCCESS) {
return false;
}
memcpy(data, buf, sz);
data += sz;
address += sz;
length -= sz;
}
// nrfx_qspi_read works in 4 byte increments, though it doesn't
// signal an error if sz is not a multiple of 4. Read (directly into data)
// all but the last 1, 2, or 3 bytes depending on the (remaining) length.
uint32_t sz = length & ~(uint32_t)3;
if(nrfx_qspi_read(data, sz, address) != NRFX_SUCCESS) {
return false;
}
data += sz;
address += sz;
length -= sz;
// Now, if we have any bytes left over, we must do a final read of 4
// bytes and copy 1, 2, or 3 bytes to data.
if(length) {
__attribute__((aligned(4))) uint8_t buf[4];
if(nrfx_qspi_read(buf, 4, address) != NRFX_SUCCESS) {
return false;
}
memcpy(data, buf, length);
}
return true;
}
void spi_flash_init(void) {

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