--- /dev/null
+/*
+ * 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 = mtd_device_register(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 */
+ mtd_device_unregister(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);
projects / 15.05 / openwrt.git / blobdiff