This patch adds support for flashing zImage to the Android boot partition on eMMC.

Usage:

$ fastboot flash zImage <path_to_zImage>

It's based on [1].

[1] http://omapzoom.org/?p=repo/u-boot.git;a=commit;h=3393b908c1e848bba3706612cb...

Signed-off-by: Sam Protsenko semen.protsenko@linaro.org --- common/fb_mmc.c | 166 ++++++++++++++++++++++++++++++++++++++++++++++++ include/android_image.h | 2 + include/linux/compat.h | 3 + 3 files changed, 171 insertions(+)

diff --git a/common/fb_mmc.c b/common/fb_mmc.c index 866982e41c..5fb2b05845 100644 --- a/common/fb_mmc.c +++ b/common/fb_mmc.c @@ -4,6 +4,7 @@ * SPDX-License-Identifier: GPL-2.0+ */

+#include <android_image.h> #include <config.h> #include <common.h> #include <blk.h> @@ -11,6 +12,7 @@ #include <fb_mmc.h> #include <image-sparse.h> #include <part.h> +#include <linux/compat.h> #include <mmc.h> #include <div64.h>

@@ -27,6 +29,8 @@ #define CONFIG_FASTBOOT_MBR_NAME "mbr" #endif

+#define BOOT_PARTITION_NAME "boot" + struct fb_mmc_sparse { struct blk_desc *dev_desc; }; @@ -99,6 +103,163 @@ static void write_raw_image(struct blk_desc *dev_desc, disk_partition_t *info, fastboot_okay(""); }

+/** + * Read Android boot image header from boot partition. + * + * @param[in] dev_desc MMC device descriptor + * @param[in] info Boot partition info + * @param[out] hdr Where to store read boot image header + * + * @return Boot image header sectors count or 0 on error + */ +static lbaint_t fb_mmc_get_boot_header(struct blk_desc *dev_desc, + disk_partition_t *info, + struct andr_img_hdr *hdr) +{ + ulong sector_size; /* boot partition sector size */ + lbaint_t hdr_sectors; /* boot image header sectors count */ + int res; + + /* Calculate boot image sectors count */ + sector_size = info->blksz; + hdr_sectors = DIV_ROUND_UP(sizeof(struct andr_img_hdr), sector_size); + if (hdr_sectors == 0) { + error("invalid number of boot sectors: 0"); + fastboot_fail("invalid number of boot sectors: 0"); + return 0; + } + + /* Read the boot image header */ + res = dev_desc->block_read(dev_desc, info->start, hdr_sectors, + (void *)hdr); + if (res == 0) { + error("cannot read header from boot partition"); + fastboot_fail("cannot read header from boot partition"); + return 0; + } + + /* Check boot header magic string */ + res = android_image_check_header(hdr); + if (res != 0) { + error("bad boot image magic"); + fastboot_fail("boot partition not initialized"); + return 0; + } + + return hdr_sectors; +} + +/** + * Write downloaded zImage to boot partition and repack it properly. + * + * @param dev_desc MMC device descriptor + * @param download_buffer Address to fastboot buffer with zImage in it + * @param download_bytes Size of fastboot buffer, in bytes + * + * @return 0 on success or -1 on error + */ +static int fb_mmc_update_zimage(struct blk_desc *dev_desc, + void *download_buffer, + unsigned int download_bytes) +{ + u32 hdr_addr; /* boot image header address */ + struct andr_img_hdr *hdr; /* boot image header */ + lbaint_t hdr_sectors; /* boot image header sectors */ + u8 *ramdisk_buffer; + u32 ramdisk_sector_start; + u32 ramdisk_sectors; + u32 kernel_sector_start; + u32 kernel_sectors; + u32 sectors_per_page; + disk_partition_t info; + int res; + + puts("Flashing zImage\n"); + + /* Get boot partition info */ + res = part_get_info_by_name(dev_desc, BOOT_PARTITION_NAME, &info); + if (res < 0) { + error("cannot find boot partition"); + fastboot_fail("cannot find boot partition"); + return -1; + } + + /* Put boot image header in fastboot buffer after downloaded zImage */ + hdr_addr = (u32)download_buffer + PAGE_ALIGN(download_bytes); + hdr = (struct andr_img_hdr *)hdr_addr; + + /* Read boot image header */ + hdr_sectors = fb_mmc_get_boot_header(dev_desc, &info, hdr); + if (hdr_sectors == 0) { + error("unable to read boot image header"); + fastboot_fail("unable to read boot image header"); + return -1; + } + + /* Check if boot image has second stage in it (we don't support it) */ + if (hdr->second_size > 0) { + error("moving second stage is not supported yet"); + fastboot_fail("moving second stage is not supported yet"); + return -1; + } + + /* Extract ramdisk location */ + sectors_per_page = hdr->page_size / info.blksz; + ramdisk_sector_start = info.start + sectors_per_page; + ramdisk_sector_start += DIV_ROUND_UP(hdr->kernel_size, hdr->page_size) * + sectors_per_page; + ramdisk_sectors = DIV_ROUND_UP(hdr->ramdisk_size, hdr->page_size) * + sectors_per_page; + + /* Read ramdisk and put it in fastboot buffer after boot image header */ + ramdisk_buffer = (u8 *)hdr + (hdr_sectors * info.blksz); + res = dev_desc->block_read(dev_desc, ramdisk_sector_start, + ramdisk_sectors, ramdisk_buffer); + if (res == 0) { + error("cannot read ramdisk from boot partition"); + fastboot_fail("cannot read ramdisk from boot partition"); + return -1; + } + + /* Write new kernel size to boot image header */ + hdr->kernel_size = download_bytes; + res = dev_desc->block_write(dev_desc, info.start, + hdr_sectors, (void *)hdr); + if (res == 0) { + error("cannot writeback boot image header"); + fastboot_fail("cannot write back boot image header"); + return -1; + } + + /* Write the new downloaded kernel */ + kernel_sector_start = info.start + sectors_per_page; + kernel_sectors = DIV_ROUND_UP(hdr->kernel_size, hdr->page_size) * + sectors_per_page; + res = dev_desc->block_write(dev_desc, kernel_sector_start, + kernel_sectors, download_buffer); + if (res == 0) { + error("cannot write new kernel"); + fastboot_fail("cannot write new kernel"); + return -1; + } + + /* Write the saved ramdisk back */ + ramdisk_sector_start = info.start + sectors_per_page; + ramdisk_sector_start += DIV_ROUND_UP(hdr->kernel_size, hdr->page_size) * + sectors_per_page; + res = dev_desc->block_write(dev_desc, ramdisk_sector_start, + ramdisk_sectors, ramdisk_buffer); + if (res == 0) { + error("cannot write back original ramdisk"); + fastboot_fail("cannot write back original ramdisk"); + return -1; + } + + puts("........ zImage was updated in boot partition\n"); + fastboot_okay(""); + return 0; +} + void fb_mmc_flash_write(const char *cmd, void *download_buffer, unsigned int download_bytes) { @@ -153,6 +314,11 @@ void fb_mmc_flash_write(const char *cmd, void *download_buffer, } #endif

+ if (strcmp(cmd, "zImage") == 0 || strcmp(cmd, "zimage") == 0) { + fb_mmc_update_zimage(dev_desc, download_buffer, download_bytes); + return; + } + if (part_get_info_by_name_or_alias(dev_desc, cmd, &info) < 0) { error("cannot find partition: '%s'\n", cmd); fastboot_fail("cannot find partition"); diff --git a/include/android_image.h b/include/android_image.h index dfd4d9d72c..c058b1d388 100644 --- a/include/android_image.h +++ b/include/android_image.h @@ -12,6 +12,8 @@ #ifndef _ANDROID_IMAGE_H_ #define _ANDROID_IMAGE_H_

+#include <linux/types.h> + typedef struct andr_img_hdr andr_img_hdr;

#define ANDR_BOOT_MAGIC "ANDROID!" diff --git a/include/linux/compat.h b/include/linux/compat.h index a43e4d6698..b0ff6b91f0 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -111,6 +111,9 @@ static inline void kmem_cache_destroy(struct kmem_cache *cachep)

#define PAGE_SIZE 4096

+/* to align the pointer to the (next) page boundary */ +#define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE) + /* drivers/char/random.c */ #define get_random_bytes(...)