嵌入式系统系统升级内核双备份的实现方式

1.nand flash MTD分区

kernels/linux-2.6.31.1-cavm1/drivers/mtd/maps/xxxxx-flash.c

/* MTD partitions: From CNW5602 32MB

* mtd0: 0x000C0000 00020000 "bootloader"

* mtd1: 0x00040000 00020000 "factory_config"

* mtd2: 0x00100000 00020000 "sysconfig"

* mtd3: 0x00DE0000 00020000 "kernel_and_fs"

* mtd4: 0x00020000 00020000 "bootloader_env"

* mtd5: 0x00DE0000 00020000 "kernel_and_fs_backup"

* mtd6: 0x001E0000 00020000 "syslog"

* mtd7: 0x00020000 00020000 "transconfig"

* mtd8: 0x00020000 00020000 "factoryconfig"

*/

static struct mtd_partition xxx_flash_partitions[] = {

{

.name = "bootloader", /* u-boot 6 sector (768KB), 0x20000-0xC0000: Reserved Space */

.size = 0x000C0000, /* 0x00000000 .. 0x000BFFFF */

.offset = 0,

.mask_flags = MTD_WRITEABLE, /* force read-only */

}, {

.name = "factory_config", /* Static Configuration from factory, (256KB = 128KB used + 128KB reserved) */

.size = 0x00040000, /* 0x000C0000 .. 0x000FFFFF */

.offset = MTDPART_OFS_APPEND,

.mask_flags = MTD_WRITEABLE, /* force read-only */

}, {

.name = "sysconfig", /* sysconfig 8 sector (1024KB) */

.size = 0x00100000, /* 0x00100000 .. 0x001FFFFF */

.offset = MTDPART_OFS_APPEND,

}, {

.name = "kernel_and_fs", /* Linux Kernel and File System (bootpImage) (14208KB) */

.size = 0x00DE0000, /* 0x00200000 .. 0x00FDFFFF */

.offset = MTDPART_OFS_APPEND,

}, {

.name = "bootloader_env", /* bottom 1 sector (128KB) for u-boot env variables */

.size = 0x00020000, /* 0x00FE0000 .. 0x00FFFFFF */

.offset = MTDPART_OFS_APPEND,

}, {

.name = "kernel_and_fs_backup", /* Linux Kernel and File System (bootpImage) (14208KB) */

.size = 0x00DE0000, /* 0x01000000 .. 0x01DDFFFF */

.offset = MTDPART_OFS_APPEND,

}, {

.name = "syslog", /* syslog 15 sector (1920KB) */

.size = 0x001E0000, /* 0x01DE0000 .. 0x01FBFFFF */

.offset = MTDPART_OFS_APPEND,

}, {

.name = "transconfig", /* transconfig 1 sector (128KB) */

.size = 0x00020000, /* 0x01FC0000 .. 0x01FDFFFF */

.offset = MTDPART_OFS_APPEND,

}, {

.name = "factoryconfig", /* factoryconfig 1 sector (128KB) */

.size = MTDPART_SIZ_FULL, /* 0x01FE0000 .. 0x01FFFFFF */ /* MTDPART_SIZ_FULL= 0x00020000 */

.offset = MTDPART_OFS_APPEND,

}

};

2.在应用层读写open("/dev/mtd3", O_RDWR);