[U-Boot] [PATCH] fastboot: Add support for flashing zImage
Sam Protsenko
semen.protsenko at linaro.org
Wed May 17 13:18:33 UTC 2017
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=3393b908c1e848bba3706612cbe50aa8970720b3
Signed-off-by: Sam Protsenko <semen.protsenko at 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(...)
--
2.11.0
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