ubl/nandboot.c

/*
 * nandboot.c - NAND boot mode functions
 *
 * Copyright (C) 2008 Hugo Villeneuve <hugo@hugovil.com>
 *
 * Based on TI DaVinci Flash and Boot Utilities, original copyright follows:
 *   Copyright 2008 Texas Instruments, Inc. <www.ti.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include "common.h"
#include "nand.h"
#include "util.h"
#include "uart.h"

static uint8_t nand_header[MAX_PAGE_SIZE] __attribute__((section(".ddrram")));

/*
 * Find out where the application is and copy to RAM
 *   jump_entry_point: Entry point for application we are decoding out of
 *   flash
 */
int
nand_copy(uint32_t *jump_entry_point)
{
	uint32_t count, start_block;
	uint32_t i;
	uint32_t magicNum;
	uint32_t block, page;
	uint32_t readError = E_FAIL;
	int failedOnceAlready = false;
	uint8_t *rxBuf; /* Temporary buffer to load header in NAND */
	struct nand_image_descriptor_t im_desc;
	int last_header_block;

	start_block = START_UBOOT_BLOCK_NUM;
	last_header_block = END_UBOOT_BLOCK_NUM;

NAND_startAgain:
	failedOnceAlready = false;

	/* Read header about application starting at START_UBOOT_BLOCK_NUM, Page 0
	 * and try 50 blocks. */
	for (count = start_block; count <= last_header_block; count++) {
		if (nand_read_page(count, 0, nand_header) != E_PASS)
			continue;

		magicNum = *((uint32_t *) nand_header);

		/* Valid magic number found */
		if ((magicNum & MAGIC_NUMBER_MASK) == MAGIC_NUMBER_VALID) {
			start_block = count;
			break;
		}
	}

	/* Never found valid header. */
	if (count > last_header_block)
		return E_FAIL;

	memcpy((void *) &im_desc, nand_header, sizeof(im_desc));

	uart_send_str("Image infos: Magic = ");
	uart_send_hexnum(im_desc.magic, 8);
	uart_send_str(", Entry = ");
	uart_send_hexnum(im_desc.entry_point, 8);
	uart_send_str(", Pages = ");
	uart_send_hexnum(im_desc.size_in_pages, 8);
	uart_send_str(", Load = ");
	uart_send_hexnum(im_desc.load_address, 8);
	uart_send_str(", Block = ");
	uart_send_hexnum(im_desc.block_num, 8);
	uart_send_lf();

	rxBuf = (uint8_t *) im_desc.load_address;

NAND_retry:
	/* initialize block and page number to be used for read */
	block = im_desc.block_num;
	page = im_desc.page_num;

	/* Perform the actual copying of the application from NAND to RAM */
	for (i = 0; i < im_desc.size_in_pages; i++) {
		/* if page goes beyond max number of pages increment block
		 * number and reset page number */
		if (page >= nand_get_pages_per_block()) {
			page = 0;
			block++;
		}

		/* Copy the data */
		readError =
			nand_read_page(block, page++,
				       &rxBuf[i * nand_get_bytes_per_page()]);

		/*
		 * We attempt to read the app data twice. If we fail twice then
		 * we go look for a new application header in the NAND flash at
		 * the next block.
		 */
		if (readError != E_PASS) {
			if (failedOnceAlready) {
				start_block++;
				goto NAND_startAgain;
			} else {
				failedOnceAlready = true;
				goto NAND_retry;
			}
		}
	}

	/* Application was read correctly, so set entrypoint */
	*jump_entry_point = im_desc.entry_point;

	return E_PASS;
}