bootconfig.c

bootloader源代码

/*****************************************
 Copyright (c) 2001-2002 
 Sigma Designs, Inc. All Rights Reserved
 Proprietary and Confidential
 *****************************************/

/* This file is part of the boot loader */

/*
 * bootconfig.c
 *
 * first revision by Ho Lee 10/30/2002
 * configuration load & save 11/11/2002
 */

#include "config.h"
#include "uart.h"
#include "util.h"

#include "bootconfig.h"
#include "flash.h"

//
// configuration structure
//
// configuration is not saved always on the same area. because flash can't be overwritten
// and it needs erasing before writing, it is not good idea to overwrite and burn flash 
// every time. so reserve some flash area for configuration, and write the new configuration
// on the next available space, and mark which configuration is the last on the header
//
// header : (from = BOOTCONFIG_FLASHSTART, size = BOOTCONFIG_HEADSIZE)
//    signature (4 bytes) : BOOTCONFIG_HEADSIGN
//    bytes of bit-stream : bit 0 means 'configuration saved' 
//      make use of the fact that : for the flash memory, only changing bit 1 to 0 is possible
//      0xff : not saved
//      0xfe : 1 saved
//      0xfc : 2 saved
// body : (from = BOOTCONFIG_FLASHSTART + BOOTCONFIG_HEADSIZE, size = BOOTCONFIG_SIZE)
//   bootconfig_t
//

//#define BOOTCONFIG_FLASHSTART	0x1ff000
#define BOOTCONFIG_FLASHSTART	0x3ff000
//#define BOOTCONFIG_FLASHEND		0x200000
#define BOOTCONFIG_FLASHEND		0x400000
#define BOOTCONFIG_FLASHBUF		0x010000

#define BOOTCONFIG_HEADSIZE		0x100
#define BOOTCONFIG_SIZE			0x100
#define BOOTCONFIG_MAXSAVE		((BOOTCONFIG_FLASHEND - BOOTCONFIG_FLASHSTART - BOOTCONFIG_HEADSIZE) / BOOTCONFIG_SIZE)
#define BOOTCONFIG_POS(x)		(BOOTCONFIG_FLASHSTART + BOOTCONFIG_HEADSIZE + (x) * BOOTCONFIG_SIZE)

//
// global variable
//

bootconfig_t g_bootconfig = {
	1, 										// major
	0, 										// minor
	BOOTCONFIG_BODYSIGN,					// checksum
	{ 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },	// MAC address
	BOOTNET_NONE,							// protocol
	0x00000000,								// IP address
	0x00000000,								// netmask
	0x00000000,								// gateway
	0x00000000,								// server
	0x00000000,								// DNS
	"localdomain.com",						// domain
	DEFAULT_LOADER_FILENAME,				// 
	DEFAULT_ROMFS_FILENAME,					//
	DEFAULT_KERNEL_FILENAME,				//
};

//
// function prototypes
//

int bootconfig_load(int index);
int bootconfig_save(void);
int bootconfig_lastsaved(int *idx);
static int bootconfig_format(void);

//
// Load & Save
//

// index : 
//   0 : last saved
//   > 0 : specified index-th saved configuration
int bootconfig_load(int index)
{
	bootconfig_t config;
	int last;

	// check if flash exists
	if (!flash_addr_found(BOOTCONFIG_FLASHSTART))
		return 1;

	// find the last saved configuration
	if (index > 0)
		last = index;
	else if ((last = bootconfig_lastsaved(NULL)) <= 0)
		return 2;
//PrintFormat("bootconfig_load last = %d\n", last);
	// read configuration
	flash_read_data(BOOTCONFIG_POS(last - 1), &config, sizeof config);

	// check if the configuration is valid
	if (config.checksum != BOOTCONFIG_BODYSIGN)
		return 3;
	
	if (config.major_version > BOOTCONFIG_MAJOR ||
		(config.major_version == BOOTCONFIG_MAJOR && config.minor_version > BOOTCONFIG_MINOR))
		return 4;

	// load configuration to current configuration
	memcpy(&g_bootconfig, &config, sizeof g_bootconfig);

	return 0;
}

int bootconfig_save(void)
{
	int lastidx, last;
	unsigned int val;
	int needformat = 0;

	// check if flash exists
	if (!flash_addr_found(BOOTCONFIG_FLASHSTART))
		return 1;

	// find the last saved configuration
//PrintFormat("lastidx=%d last=%d\n", lastidx, last);
	if ((last = bootconfig_lastsaved(&lastidx)) <= 0 || last == BOOTCONFIG_MAXSAVE) {
		needformat = 1;
//PrintFormat("step 1 for needformat \n");
	}
	else if (!flash_writable(BOOTCONFIG_POS(last), BOOTCONFIG_SIZE))
	{
		needformat = 1;
//PrintFormat("step 2 for needformat \n");
	}

	needformat = 1;
	// if the configuration are is not formatted, or can't save any more configuration
	// format the area
	if (needformat) {
		bootconfig_format();
		lastidx = 4;
		last = 0;
	}

	PrintUart("Writing : ", -1);

	// write configuration
	flash_write_data(BOOTCONFIG_POS(last), (unsigned char *) &g_bootconfig, sizeof g_bootconfig);

	// update header
	last &= 0x07;
	val = 0xff;
	val >>= (last + 1);
	val <<= (last + 1);
	flash_write_onebyte(BOOTCONFIG_FLASHSTART + lastidx, val);

	PrintUart("\r\n", -1);

	return 0;
}

// return the last saved configuration index + 1
// return < 0 : invalid, needs formatting
// return 0 : no configuration saved 
// return x > 0 : (x - 1) configuration saved
int bootconfig_lastsaved(int *idx)
{
	int i, pos, bit;
	unsigned char head[BOOTCONFIG_HEADSIZE];

	flash_read_data(BOOTCONFIG_FLASHSTART, head, BOOTCONFIG_HEADSIZE);

	if (idx)
		*idx = 0;
	
	if (*(unsigned int *) head != BOOTCONFIG_HEADSIGN)
		return -1;

	for (i = 4, pos = 0; i < BOOTCONFIG_HEADSIZE; ++i)
		if (head[i] != 0x00) {
			pos = (i - 4) * 8;
			for (bit = 0; bit < 8; ++bit) {
				if ((head[i] & (1 << bit)) != 0)
					break;
			}
			pos += bit;
			break;
		}

	if (idx)
		*idx = i;
//PrintFormat("[bootconfig_lastsave] *idx=0x%x, pos=0x%x\n", *idx, pos);
	return pos;
}

int bootconfig_format(void)
{
	unsigned int blockstart, blocklen;
	unsigned char buf[BOOTCONFIG_FLASHBUF];

	if ((flash_calcblock(BOOTCONFIG_FLASHSTART, &blockstart, &blocklen)) != 0)
		return 1;

	if (BOOTCONFIG_FLASHBUF < blocklen) {
		PrintUart("Out of buffer memory\r\n", -1);
		return 2;
	}

	// before erasing, preserve the data
	flash_read_data(blockstart, buf, blocklen);
	memset(buf + (BOOTCONFIG_FLASHSTART - blockstart), 0xff, BOOTCONFIG_FLASHEND - BOOTCONFIG_FLASHSTART);
	*(unsigned int *)(buf + BOOTCONFIG_FLASHSTART - blockstart) = BOOTCONFIG_HEADSIGN;

PrintFormat("Erase Block Addr = 0x%x Len=%d\n", blockstart, blocklen);
	PrintUart("Formatting : ", -1);
	flash_erase_oneblock(blockstart);
	flash_write_data(blockstart, buf, blocklen);
	PrintUart("\r\n", -1);

	return 0;
}