/* * Copyright (C) Gabor Juhos <juhosg@openwrt.org> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. * */ #include <linux/module.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/list.h> #include <linux/kmod.h> #include <linux/root_dev.h> #include <linux/mtd/mtd.h> #include <linux/mtd/partitions.h> #include <linux/byteorder/generic.h> #define PFX "trxsplit: " #define TRX_MAGIC 0x30524448 /* "HDR0" */ #define TRX_VERSION 1 #define TRX_MAX_LEN 0x3A0000 #define TRX_NO_HEADER 0x1 /* do not write TRX header */ #define TRX_GZ_FILES 0x2 /* contains individual gzip files */ #define TRX_MAX_OFFSET 3 #define TRX_MIN_KERNEL_SIZE 256*1024 struct trx_header { u32 magic; /* "HDR0" */ u32 len; /* Length of file including header */ u32 crc32; /* 32-bit CRC from flag_version to end of file */ u32 flag_version; /* 0:15 flags, 16:31 version */ u32 offsets[TRX_MAX_OFFSET]; /* Offsets of partitions */ }; #define TRX_ALIGN 0x1000 static int trx_nr_parts; static unsigned long trx_offset; static struct mtd_info *trx_mtd; static struct mtd_partition trx_parts[TRX_MAX_OFFSET]; static struct trx_header trx_hdr; static int trxsplit_refresh_partitions(struct mtd_info *mtd); static int trxsplit_checktrx(struct mtd_info *mtd, unsigned long offset) { size_t retlen; int err; err = mtd->read(mtd, offset, sizeof(trx_hdr), &retlen, (void *)&trx_hdr); if (err) { printk(KERN_ALERT PFX "unable to read from '%s'\n", mtd->name); goto err_out; } if (retlen != sizeof(trx_hdr)) { printk(KERN_ALERT PFX "reading failed on '%s'\n", mtd->name); goto err_out; } trx_hdr.magic = le32_to_cpu(trx_hdr.magic); trx_hdr.len = le32_to_cpu(trx_hdr.len); trx_hdr.crc32 = le32_to_cpu(trx_hdr.crc32); trx_hdr.flag_version = le32_to_cpu(trx_hdr.flag_version); trx_hdr.offsets[0] = le32_to_cpu(trx_hdr.offsets[0]); trx_hdr.offsets[1] = le32_to_cpu(trx_hdr.offsets[1]); trx_hdr.offsets[2] = le32_to_cpu(trx_hdr.offsets[2]); /* sanity checks */ if (trx_hdr.magic != TRX_MAGIC) goto err_out; if (trx_hdr.len > mtd->size - offset) goto err_out; /* TODO: add crc32 checking too? */ return 0; err_out: return -1; } static void trxsplit_findtrx(struct mtd_info *mtd) { unsigned long offset; int err; printk(KERN_INFO PFX "searching TRX header in '%s'\n", mtd->name); err = 0; for (offset = 0; offset < mtd->size; offset += TRX_ALIGN) { err = trxsplit_checktrx(mtd, offset); if (err == 0) break; } if (err) return; printk(KERN_INFO PFX "TRX header found at 0x%lX\n", offset); trx_mtd = mtd; trx_offset = offset; } static void trxsplit_create_partitions(struct mtd_info *mtd) { struct mtd_partition *part = trx_parts; int err; int i; for (i = 0; i < TRX_MAX_OFFSET; i++) { part = &trx_parts[i]; if (trx_hdr.offsets[i] == 0) continue; part->offset = trx_offset + trx_hdr.offsets[i]; trx_nr_parts++; } for (i = 0; i < trx_nr_parts-1; i++) trx_parts[i].size = trx_parts[i+1].offset - trx_parts[i].offset; trx_parts[i].size = mtd->size - trx_parts[i].offset; i = 0; part = &trx_parts[i]; if (part->size < TRX_MIN_KERNEL_SIZE) { part->name = "loader"; i++; } part = &trx_parts[i]; part->name = "kernel"; i++; part = &trx_parts[i]; part->name = "rootfs"; err = add_mtd_partitions(mtd, trx_parts, trx_nr_parts); if (err) { printk(KERN_ALERT PFX "adding TRX partitions failed\n"); return; } mtd->refresh_device = trxsplit_refresh_partitions; } static int trxsplit_refresh_partitions(struct mtd_info *mtd) { printk(KERN_INFO PFX "refreshing TRX partitions in '%s' (%d,%d)\n", mtd->name, MTD_BLOCK_MAJOR, mtd->index); /* remove old partitions */ del_mtd_partitions(mtd); trxsplit_findtrx(mtd); if (!trx_mtd) goto err; trxsplit_create_partitions(trx_mtd); return 1; err: return 0; } static void __init trxsplit_add_mtd(struct mtd_info *mtd) { if (mtd->type != MTD_NORFLASH) { printk(KERN_INFO PFX "'%s' is not a NOR flash, skipped\n", mtd->name); return; } if (!trx_mtd) trxsplit_findtrx(mtd); } static void __init trxsplit_remove_mtd(struct mtd_info *mtd) { /* nothing to do */ } static struct mtd_notifier trxsplit_notifier __initdata = { .add = trxsplit_add_mtd, .remove = trxsplit_remove_mtd, }; static void __init trxsplit_scan(void) { register_mtd_user(&trxsplit_notifier); unregister_mtd_user(&trxsplit_notifier); } static int __init trxsplit_init(void) { trxsplit_scan(); if (trx_mtd) { printk(KERN_INFO PFX "creating TRX partitions in '%s' " "(%d,%d)\n", trx_mtd->name, MTD_BLOCK_MAJOR, trx_mtd->index); trxsplit_create_partitions(trx_mtd); } return 0; } late_initcall(trxsplit_init);