bootstrap.c

uboot详细解读可用启动引导LINUX2.6内核

/*
 * (C) Copyright 2008
 * Stefan Roese, DENX Software Engineering, [e-mail].
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 *
 */

#include <common.h>
#include <command.h>
#include <i2c.h>
#include <asm/io.h>

/*
 * NOR and NAND boot options change bytes 5, 6, 8, 9, 11. The
 * values are independent of the rest of the clock settings.
 */

#define NAND_COMPATIBLE	0x01
#define NOR_COMPATIBLE  0x02

#define I2C_EEPROM_ADDR 0x52

static char *config_labels[] = {
	"CPU: 600 PLB: 200 OPB: 100 EBC: 100",
	"CPU: 800 PLB: 200 OPB: 100 EBC: 100",
	NULL
};

static u8 boot_configs[][17] = {
	{
		(NAND_COMPATIBLE | NOR_COMPATIBLE),
		0x86, 0x80, 0xce, 0x1f, 0x79, 0x80, 0x00, 0xa0, 0x40, 0x08,
		0x23, 0x50, 0x0d, 0x05, 0x00, 0x00
	},
	{
		(NAND_COMPATIBLE | NOR_COMPATIBLE),
		0x86, 0x80, 0xba, 0x14, 0x99, 0x80, 0x00, 0xa0, 0x40, 0x08,
		0x23, 0x50, 0x0d, 0x05, 0x00, 0x00
	},
	{
		0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
	}
};

/*
 * Bytes 5,6,8,9,11 change for NAND boot
 */
#if 0
/*
 * Values for 512 page size NAND chips, not used anymore, just
 * keep them here for reference
 */
static u8 nand_boot[] = {
	0x90, 0x01,  0xa0, 0x68, 0x58
};
#else
/*
 * Values for 2k page size NAND chips
 */
static u8 nand_boot[] = {
	0x90, 0x01,  0xa0, 0xe8, 0x58
};
#endif

static int do_bootstrap(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
	u8 *buf, b_nand;
	int x, y, nbytes, selcfg;
	extern char console_buffer[];

	if (argc < 2) {
		printf("Usage:\n%s\n", cmdtp->usage);
		return 1;
	}

	if ((strcmp(argv[1], "nor") != 0) &&
	    (strcmp(argv[1], "nand") != 0)) {
		printf("Unsupported boot-device - only nor|nand support\n");
		return 1;
	}

	/* set the nand flag based on provided input */
	if ((strcmp(argv[1], "nand") == 0))
		b_nand = 1;
	else
		b_nand = 0;

	printf("Available configurations: \n\n");

	if (b_nand) {
		for(x = 0, y = 0; boot_configs[x][0] != 0; x++) {
			/* filter on nand compatible */
			if (boot_configs[x][0] & NAND_COMPATIBLE) {
				printf(" %d - %s\n", (y+1), config_labels[x]);
				y++;
			}
		}
	} else {
		for(x = 0, y = 0; boot_configs[x][0] != 0; x++) {
			/* filter on nor compatible */
			if (boot_configs[x][0] & NOR_COMPATIBLE) {
				printf(" %d - %s\n", (y+1), config_labels[x]);
				y++;
			}
		}
	}

	do {
		nbytes = readline(" Selection [1-x / quit]: ");

		if (nbytes) {
			if (strcmp(console_buffer, "quit") == 0)
				return 0;
			selcfg = simple_strtol(console_buffer, NULL, 10);
			if ((selcfg < 1) || (selcfg > y))
				nbytes = 0;
		}
	} while (nbytes == 0);


	y = (selcfg - 1);

	for (x = 0; boot_configs[x][0] != 0; x++) {
		if (b_nand) {
			if (boot_configs[x][0] & NAND_COMPATIBLE) {
				if (y > 0)
					y--;
				else if (y < 1)
					break;
			}
		} else {
			if (boot_configs[x][0] & NOR_COMPATIBLE) {
				if (y > 0)
					y--;
				else if (y < 1)
					break;
			}
		}
	}

	buf = &boot_configs[x][1];

	if (b_nand) {
		buf[5] = nand_boot[0];
		buf[6] = nand_boot[1];
		buf[8] = nand_boot[2];
		buf[9] = nand_boot[3];
		buf[11] = nand_boot[4];
	}

	if (i2c_write(I2C_EEPROM_ADDR, 0, 1, buf, 16) != 0)
		printf("Error writing to EEPROM at address 0x%x\n", I2C_EEPROM_ADDR);
	udelay(CFG_EEPROM_PAGE_WRITE_DELAY_MS * 1000);

	printf("Done\n");
	printf("Please power-cycle the board for the changes to take effect\n");

	return 0;
}

U_BOOT_CMD(
	bootstrap,	2,	0,	do_bootstrap,
	"bootstrap - program the I2C bootstrap EEPROM\n",
	"<nand|nor> - strap to boot from NAND or NOR flash\n"
	);