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