fastboot: Add support for flashing zImage

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@linaro.org>

diff --git a/common/fb_mmc.c b/common/fb_mmc.c
index 866982e41c0880940d9e25fe0164773323ac241a..2113b6c3723978f31372e1562010e76defb6f800 100644 (file)
--- a/common/fb_mmc.c
+++ b/common/fb_mmc.c
@@ -13,6 +13,8 @@
 #include <part.h>
 #include <mmc.h>
 #include <div64.h>
+#include <linux/compat.h>
+#include <android_image.h>
 
 /*
  * FIXME: Ensure we always set these names via Kconfig once xxx_PARTITION is
@@ -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("");
 }
 
+#ifdef CONFIG_ANDROID_BOOT_IMAGE
+/**
+ * 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 = blk_dread(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 + ALIGN(download_bytes, PAGE_SIZE);
+       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 = blk_dread(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 = blk_dwrite(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 = blk_dwrite(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 = blk_dwrite(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;
+}
+#endif
+
 void fb_mmc_flash_write(const char *cmd, void *download_buffer,
                        unsigned int download_bytes)
 {
@@ -153,6 +314,13 @@ void fb_mmc_flash_write(const char *cmd, void *download_buffer,
        }
 #endif
 
+#ifdef CONFIG_ANDROID_BOOT_IMAGE
+       if (strncasecmp(cmd, "zimage", 6) == 0) {
+               fb_mmc_update_zimage(dev_desc, download_buffer, download_bytes);
+               return;
+       }
+#endif
+
        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");