Function flashconsole_init

src/drivers/spi/flashconsole.c:19–68

static size_t line_offset;

void flashconsole_init(void)
{
	uint8_t buffer[READ_BUFFER_SIZE];
	size_t size;
	size_t initial_offset = 0;
	size_t len = READ_BUFFER_SIZE;
	size_t i;

	if (fmap_locate_area_as_rdev_rw("CONSOLE", &rdev)) {
		printk(BIOS_INFO, "Can't find 'CONSOLE' area in FMAP\n");
		return;
	}
	size = region_device_sz(&rdev);

	/*
	 * We need to check the region until we find a 0xff indicating
	 * the end of a previous log write.
	 * We can't erase the region because one stage would erase the
	 * data from the previous stage. Also, it looks like doing an
	 * erase could completely freeze the SPI controller and then
	 * we can't write anything anymore (apparently might happen if
	 * the sector is already erased, so we would need to read
	 * anyways to check if it's all 0xff).
	 */
	for (i = 0; i < len && initial_offset < size;) {
		// Fill the buffer on first iteration
		if (i == 0) {
			len = MIN(READ_BUFFER_SIZE, size - offset);
			if (rdev_readat(&rdev, buffer, initial_offset, len) != len)
				return;
		}
		if (buffer[i] == 0xff) {
			initial_offset += i;
			break;
		}
		// If we're done, repeat the process for the next sector
		if (++i == READ_BUFFER_SIZE) {
			initial_offset += len;
			i = 0;
		}
	}
	// Make sure there is still space left on the console
	if (initial_offset >= size) {
		printk(BIOS_INFO, "No space left on 'console' region in SPI flash\n");
		return;
	}

	offset = initial_offset;
	rdev_ptr = &rdev;
}

void flashconsole_tx_byte(unsigned char c)
{