blob: 984f98923446a5406ca84dca0879909049af0849 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright © 2022 Rafał Miłecki <rafal@milecki.pl>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#define BRCM_U_BOOT_MAX_OFFSET 0x200000
#define BRCM_U_BOOT_STEP 0x1000
#define BRCM_U_BOOT_MAX_PARTS 2
#define BRCM_U_BOOT_MAGIC 0x75456e76 /* uEnv */
struct brcm_u_boot_header {
__le32 magic;
__le32 length;
} __packed;
static const char *names[BRCM_U_BOOT_MAX_PARTS] = {
"u-boot-env",
"u-boot-env-backup",
};
static int brcm_u_boot_parse(struct mtd_info *mtd,
const struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
struct brcm_u_boot_header header;
struct mtd_partition *parts;
size_t bytes_read;
size_t offset;
int err;
int i = 0;
parts = kcalloc(BRCM_U_BOOT_MAX_PARTS, sizeof(*parts), GFP_KERNEL);
if (!parts)
return -ENOMEM;
for (offset = 0;
offset < min_t(size_t, mtd->size, BRCM_U_BOOT_MAX_OFFSET);
offset += BRCM_U_BOOT_STEP) {
err = mtd_read(mtd, offset, sizeof(header), &bytes_read, (uint8_t *)&header);
if (err && !mtd_is_bitflip(err)) {
pr_err("Failed to read from %s at 0x%zx: %d\n", mtd->name, offset, err);
continue;
}
if (le32_to_cpu(header.magic) != BRCM_U_BOOT_MAGIC)
continue;
parts[i].name = names[i];
parts[i].offset = offset;
parts[i].size = sizeof(header) + le32_to_cpu(header.length);
i++;
pr_info("offset:0x%zx magic:0x%08x BINGO\n", offset, header.magic);
if (i == BRCM_U_BOOT_MAX_PARTS)
break;
}
*pparts = parts;
return i;
};
static const struct of_device_id brcm_u_boot_of_match_table[] = {
{ .compatible = "brcm,u-boot" },
{},
};
MODULE_DEVICE_TABLE(of, brcm_u_boot_of_match_table);
static struct mtd_part_parser brcm_u_boot_mtd_parser = {
.parse_fn = brcm_u_boot_parse,
.name = "brcm_u-boot",
.of_match_table = brcm_u_boot_of_match_table,
};
module_mtd_part_parser(brcm_u_boot_mtd_parser);
MODULE_DESCRIPTION("Broadcom's U-Boot partition parser");
MODULE_LICENSE("GPL");