[PATCH v3 16/19] android: boot: support bootconfig

[Safae Ouajih]

Support Bootconfig feature.
- The bootconfig feature replaces the androidboot.*
  kernel cmdline options.

This was adapted from downstream [1] commit : 7af0a0506d4d ("cuttlefish:
support bootconfig parameters").

Link:[1] https://android.googlesource.com/platform/external/u-boot/

Signed-off-by: Safae Ouajih <soua...@baylibre.com>
Reviewed-by: Simon Glass <s...@chromium.org>
Reviewed-by: Mattijs Korpershoek <mkorpersh...@baylibre.com>
---
 boot/image-android.c    | 58 +++++++++++++++++++++++++++++++++++++++--
 include/android_image.h | 11 ++++++++
 2 files changed, 67 insertions(+), 2 deletions(-)

diff --git a/boot/image-android.c b/boot/image-android.c
index fb29ff403f..88e40bc7ec 100644
--- a/boot/image-android.c
+++ b/boot/image-android.c
@@ -18,6 +18,45 @@
 
 static char andr_tmp_str[ANDR_BOOT_ARGS_SIZE + 1];
 
+static ulong checksum(const unsigned char *buffer, ulong size)
+{
+       ulong sum = 0;
+
+       for (ulong i = 0; i < size; i++)
+               sum += buffer[i];
+       return sum;
+}
+
+static bool is_trailer_present(ulong bootconfig_end_addr)
+{
+       return !strncmp((char *)(bootconfig_end_addr - BOOTCONFIG_MAGIC_SIZE),
+                       BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_SIZE);
+}
+
+static ulong add_trailer(ulong bootconfig_start_addr, ulong bootconfig_size)
+{
+       ulong end;
+       ulong sum;
+
+       if (!bootconfig_start_addr)
+               return -1;
+       if (!bootconfig_size)
+               return 0;
+
+       end = bootconfig_start_addr + bootconfig_size;
+       if (is_trailer_present(end))
+               return 0;
+
+       memcpy((void *)(end), &bootconfig_size, BOOTCONFIG_SIZE_SIZE);
+       sum = checksum((unsigned char *)bootconfig_start_addr, bootconfig_size);
+       memcpy((void *)(end + BOOTCONFIG_SIZE_SIZE), &sum,
+              BOOTCONFIG_CHECKSUM_SIZE);
+       memcpy((void *)(end + BOOTCONFIG_SIZE_SIZE + BOOTCONFIG_CHECKSUM_SIZE),
+              BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_SIZE);
+
+       return BOOTCONFIG_TRAILER_SIZE;
+}
+
 static void android_boot_image_v3_v4_parse_hdr(const struct 
andr_boot_img_hdr_v3 *hdr,
                                               struct andr_image_data *data)
 {
@@ -61,6 +100,7 @@ static void android_vendor_boot_image_v3_v4_parse_hdr(const 
struct andr_vnd_boot
        data->kernel_addr = hdr->kernel_addr;
        data->ramdisk_addr = hdr->ramdisk_addr;
        data->dtb_load_addr = hdr->dtb_addr;
+       data->bootconfig_size = hdr->bootconfig_size;
        end = (ulong)hdr;
        end += hdr->page_size;
        if (hdr->vendor_ramdisk_size) {
@@ -75,7 +115,13 @@ static void android_vendor_boot_image_v3_v4_parse_hdr(const 
struct andr_vnd_boot
 
        end += ALIGN(hdr->dtb_size, hdr->page_size);
        end += ALIGN(hdr->vendor_ramdisk_table_size, hdr->page_size);
-       end += ALIGN(hdr->bootconfig_size, hdr->page_size);
+       data->bootconfig_addr = end;
+       if (hdr->bootconfig_size) {
+               data->bootconfig_size += add_trailer(data->bootconfig_addr,
+                                                    data->bootconfig_size);
+               data->ramdisk_size += data->bootconfig_size;
+       }
+       end += ALIGN(data->bootconfig_size, hdr->page_size);
        data->vendor_boot_img_total_size = end - (ulong)hdr;
 }
 
@@ -352,7 +398,15 @@ int android_image_get_ramdisk(const void *hdr, const void 
*vendor_boot_img,
                memcpy((void *)(ramdisk_ptr), (void 
*)img_data.vendor_ramdisk_ptr,
                       img_data.vendor_ramdisk_size);
                memcpy((void *)(ramdisk_ptr + img_data.vendor_ramdisk_size),
-                      (void *)img_data.ramdisk_ptr, 
img_data.boot_ramdisk_size);
+                      (void *)img_data.ramdisk_ptr,
+                      img_data.boot_ramdisk_size);
+               if (img_data.bootconfig_size) {
+                       memcpy((void *)
+                              (ramdisk_ptr + img_data.vendor_ramdisk_size +
+                              img_data.boot_ramdisk_size),
+                              (void *)img_data.bootconfig_addr,
+                              img_data.bootconfig_size);
+               }
        }
 
        printf("RAM disk load addr 0x%08lx size %u KiB\n",
diff --git a/include/android_image.h b/include/android_image.h
index 99e7803508..d503c980b2 100644
--- a/include/android_image.h
+++ b/include/android_image.h
@@ -25,6 +25,14 @@
 #define ANDR_VENDOR_BOOT_ARGS_SIZE 2048
 #define ANDR_VENDOR_BOOT_NAME_SIZE 16
 
+#define BOOTCONFIG_MAGIC "#BOOTCONFIG\n"
+#define BOOTCONFIG_MAGIC_SIZE 12
+#define BOOTCONFIG_SIZE_SIZE 4
+#define BOOTCONFIG_CHECKSUM_SIZE 4
+#define BOOTCONFIG_TRAILER_SIZE BOOTCONFIG_MAGIC_SIZE + \
+                               BOOTCONFIG_SIZE_SIZE + \
+                               BOOTCONFIG_CHECKSUM_SIZE
+
 struct andr_boot_img_hdr_v3 {
        u8 magic[ANDR_BOOT_MAGIC_SIZE];
 
@@ -337,6 +345,9 @@ struct andr_image_data {
        const char *kcmdline_extra;  /* vendor-boot extra kernel cmdline */
        const char *image_name;  /* asciiz product name */
 
+       ulong bootconfig_addr;  /* bootconfig image address */
+       ulong bootconfig_size;  /* bootconfig image size */
+
        u32 kernel_addr;  /* physical load addr */
        ulong ramdisk_addr;  /* physical load addr */
        ulong ramdisk_ptr;  /* ramdisk address */
-- 
2.34.1