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- From 002181f5b150e60c77f21de7ad4dd10e4614cd91 Mon Sep 17 00:00:00 2001
- From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <[email protected]>
- Date: Mon, 11 Jul 2022 17:30:41 +0200
- Subject: [PATCH] mtd: parsers: add Broadcom's U-Boot parser
- MIME-Version: 1.0
- Content-Type: text/plain; charset=UTF-8
- Content-Transfer-Encoding: 8bit
- Broadcom stores environment variables blocks inside U-Boot partition
- itself. This driver finds & registers them.
- Signed-off-by: Rafał Miłecki <[email protected]>
- Signed-off-by: Miquel Raynal <[email protected]>
- Link: https://lore.kernel.org/linux-mtd/[email protected]
- ---
- drivers/mtd/parsers/Kconfig | 10 ++++
- drivers/mtd/parsers/Makefile | 1 +
- drivers/mtd/parsers/brcm_u-boot.c | 84 +++++++++++++++++++++++++++++++
- 3 files changed, 95 insertions(+)
- create mode 100644 drivers/mtd/parsers/brcm_u-boot.c
- --- a/drivers/mtd/parsers/Kconfig
- +++ b/drivers/mtd/parsers/Kconfig
- @@ -20,6 +20,16 @@ config MTD_BCM63XX_PARTS
- This provides partition parsing for BCM63xx devices with CFE
- bootloaders.
-
- +config MTD_BRCM_U_BOOT
- + tristate "Broadcom's U-Boot partition parser"
- + depends on ARCH_BCM4908 || COMPILE_TEST
- + help
- + Broadcom uses a custom way of storing U-Boot environment variables.
- + They are placed inside U-Boot partition itself at unspecified offset.
- + It's possible to locate them by looking for a custom header with a
- + magic value. This driver does that and creates subpartitions for
- + each found environment variables block.
- +
- config MTD_CMDLINE_PARTS
- tristate "Command line partition table parsing"
- depends on MTD
- --- a/drivers/mtd/parsers/Makefile
- +++ b/drivers/mtd/parsers/Makefile
- @@ -2,6 +2,7 @@
- obj-$(CONFIG_MTD_AR7_PARTS) += ar7part.o
- obj-$(CONFIG_MTD_BCM47XX_PARTS) += bcm47xxpart.o
- obj-$(CONFIG_MTD_BCM63XX_PARTS) += bcm63xxpart.o
- +obj-$(CONFIG_MTD_BRCM_U_BOOT) += brcm_u-boot.o
- obj-$(CONFIG_MTD_CMDLINE_PARTS) += cmdlinepart.o
- obj-$(CONFIG_MTD_MYLOADER_PARTS) += myloader.o
- obj-$(CONFIG_MTD_OF_PARTS) += ofpart.o
- --- /dev/null
- +++ b/drivers/mtd/parsers/brcm_u-boot.c
- @@ -0,0 +1,84 @@
- +// SPDX-License-Identifier: GPL-2.0-only
- +/*
- + * Copyright © 2022 Rafał Miłecki <[email protected]>
- + */
- +
- +#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_LICENSE("GPL");
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