Flashing High density device not working properly

[TheKikGen]

First, thanks for this very small bootloader, and for inspiration around HID !
I have tested the last master branch with a STM32103RC (48K RAM/256K Flash), being a HD device. The bootloader was obviously compiled with the PAGE_SIZE=2048 option.
=> The last page is not flashed, and so, the firmware is corrupted.

It seems that The ISR handle HIDUSB_HandleData doesn't take care of pending bytes at the last round if bytes > 1024 and below 2048.

static void HIDUSB_HandleData(uint8_t *data)
{
(...)
		case 0x00:

			/* Reset Page Command */
			UploadStarted = true;
			CurrentPage = MIN_PAGE;
			CurrentPageOffset = 0;
		break;

		case 0x01:
=> SOMETHING SHOULD BE DONE HERE TO WRITE PENDING BYTES BETWEEN >1024 AND < 2048....

			/* Reboot MCU Command */
			UploadFinished = true;
		break;

		default:
			break;
		}
	} else if (CurrentPageOffset >= 
(...)

On the other end, using the same buffer for page data and commands is a bit risky.

I have written a version with some optimization , allowing the auto detection of page size (i.e. density) by reading the flash size info from the device. I also use state transitions, rather than booleans to manage the bootloader state. I push here my version of HIDUSB_HandleData

I have also separated page data from USB data until we are sure that it is page data after a full 64 bytes packet received.

static void HIDUSB_HandleData(uint8_t *data)
{
	bool writePage = false;

	memcpy(USB_Buffer + CurrentPacketOffset, data, MAX_PACKET_SIZE);
	CurrentPacketOffset += MAX_PACKET_SIZE;

	if ( CurrentPacketOffset < MAX_BUFFER_SIZE ) return;
	CurrentPacketOffset = 0;
	uint8_t cmd  = HIDUSB_PacketIsCommand();

	if ( cmd == CMD_START ) {
			BootloaderState = BTL_STARTED;
			return;
	}

	if ( cmd == CMD_END ) {
		if (CurrentPageOffset) writePage = true;
		BootloaderState = BTL_END;
	}
	else if (BootloaderState == BTL_STARTED) {
		memcpy(PageData + CurrentPageOffset, USB_Buffer, MAX_BUFFER_SIZE);
		CurrentPageOffset += MAX_BUFFER_SIZE;
		if ( CurrentPageOffset % 1024 == 0) {
				USB_SendData(ENDP1, (uint16_t *) CMD_SIGN, sizeof (CMD_SIGN));
				if (CurrentPageOffset == PageSize ) writePage = true;
		}
	}

	// Write a page to the flash memory
	if ( writePage ) {
			LED1_ON;
			FLASH_WritePage((uint16_t *)(FLASH_BASE_ADDR + CurrentPage * PageSize),
			 				(uint16_t *) PageData, CurrentPageOffset / 2);
			CurrentPage++;
			CurrentPageOffset = 0;
			writePage = false;
			LED1_OFF;
	}

}

To save room, and stay below 2K, the USB string descriptors can be commented as they are not really used with generic HID devices.

Hope this helps.

[TheKikGen]

https://github.com/TheKikGen/stm32-tkg-hid-bootloader