diff --git a/src/machine/machine_atsamd51.go b/src/machine/machine_atsamd51.go index d169eab995..8e302cdc4c 100644 --- a/src/machine/machine_atsamd51.go +++ b/src/machine/machine_atsamd51.go @@ -2163,7 +2163,7 @@ func (f flashBlockDevice) ReadAt(p []byte, off int64) (n int, err error) { } // WriteAt writes the given number of bytes to the block device. -// Only word (32 bits) length data can be programmed. +// Data is written to the page buffer in 4-byte chunks, then saved to flash memory. // See SAM-D5x-E5x-Family-Data-Sheet-DS60001507.pdf page 591-592. // If the length of p is not long enough it will be padded with 0xFF bytes. // This method assumes that the destination is already erased. @@ -2185,16 +2185,13 @@ func (f flashBlockDevice) WriteAt(p []byte, off int64) (n int, err error) { waitWhileFlashBusy() for j := 0; j < len(padded); j += int(f.WriteBlockSize()) { - // write first word using double-word low order word - *(*uint32)(unsafe.Pointer(address)) = binary.LittleEndian.Uint32(padded[j : j+int(f.WriteBlockSize()/2)]) - - // write second word using double-word high order word - *(*uint32)(unsafe.Add(unsafe.Pointer(address), uintptr(f.WriteBlockSize())/2)) = binary.LittleEndian.Uint32(padded[j+int(f.WriteBlockSize()/2) : j+int(f.WriteBlockSize())]) - - waitWhileFlashBusy() + // page buffer is 512 bytes long, but only 4 bytes can be written at once + for k := 0; k < int(f.WriteBlockSize()); k += 4 { + *(*uint32)(unsafe.Pointer(address + uintptr(k))) = binary.LittleEndian.Uint32(padded[j+k : j+k+4]) + } sam.NVMCTRL.SetADDR(uint32(address)) - sam.NVMCTRL.CTRLB.Set(sam.NVMCTRL_CTRLB_CMD_WQW | (sam.NVMCTRL_CTRLB_CMDEX_KEY << sam.NVMCTRL_CTRLB_CMDEX_Pos)) + sam.NVMCTRL.CTRLB.Set(sam.NVMCTRL_CTRLB_CMD_WP | (sam.NVMCTRL_CTRLB_CMDEX_KEY << sam.NVMCTRL_CTRLB_CMDEX_Pos)) waitWhileFlashBusy() @@ -2213,7 +2210,7 @@ func (f flashBlockDevice) Size() int64 { return int64(FlashDataEnd() - FlashDataStart()) } -const writeBlockSize = 8 +const writeBlockSize = 512 // WriteBlockSize returns the block size in which data can be written to // memory. It can be used by a client to optimize writes, non-aligned writes