[PATCH v3 3/5] boot: android: Add bootconfig support
Simon Glass
sjg at chromium.org
Wed Nov 19 14:17:01 CET 2025
Hi Guillaume,
On Fri, 14 Nov 2025 at 08:28, Guillaume La Roque (TI.com)
<glaroque at baylibre.com> wrote:
>
> For android vendor boot image version 4 bootconfig is mandatory.[1]
>
> In the android_image_get_ramdisk function, after copying both vendor and
> boot ramdisks, we extract all androidboot.* entries from the kernel
> command line. These entries are added to the bootconfig section.
> We then update the sizes of the ramdisk and bootconfig.
> Finally, all androidboot.* entries are removed from the kernel command
> line.
>
> [1] https://source.android.com/docs/core/architecture/partitions/vendor-boot-partitions#bootloader-support
> Signed-off-by: Guillaume La Roque (TI.com) <glaroque at baylibre.com>
> ---
> boot/image-android.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 109 insertions(+), 11 deletions(-)
>
Reviewed-by: Simon Glass <sjg at chromium.org>
> diff --git a/boot/image-android.c b/boot/image-android.c
> index 613f2aa4b9e..94c2879dcd6 100644
> --- a/boot/image-android.c
> +++ b/boot/image-android.c
> @@ -503,6 +503,112 @@ ulong android_image_get_kcomp(const void *hdr,
> return image_decomp_type(p, sizeof(u32));
> }
>
> +static u32 android_image_set_bootconfig(const void *hdr,
> + const void *vendor_boot_img,
> + ulong ramdisk_ptr)
This could use a comment.
Also, ramdisk_ptr is a strange name for an address as it sounds like
it is a pointer. Perhaps use ramdisk_addr ?
> +{
> + /* Extract androidboot.* parameters from bootargs */
> + const char *bootargs = env_get("bootargs");
> + char *androidboot_params = NULL;
> + char *new_bootargs = NULL;
> + size_t androidboot_params_len = 0;
As a general comment, some of the args are quite long and this makes
the code harder to read. For example this could be params_len, since
we know this is Android Boot.
> + struct andr_image_data img_data;
> + u32 bytes_added = 0;
> +
> + if (!android_image_get_data(hdr, vendor_boot_img, &img_data))
> + return 0;
> +
> + if (bootargs && img_data.bootconfig_size) {
> + size_t len = strlen(bootargs);
> +
> + androidboot_params = malloc(len + 1);
> + new_bootargs = malloc(len + 1);
> + if (!androidboot_params || !new_bootargs) {
> + free(androidboot_params);
> + free(new_bootargs);
> + printf("Error: malloc failed\n");
> + return -ENOMEM;
> + }
> +
> + /* Extract androidboot.* and build new bootargs in one pass */
> + const char *src = bootargs;
> + char *bc_dst = androidboot_params;
> + char *args_dst = new_bootargs;
> +
> + while (*src) {
> + /* Skip leading spaces */
> + while (*src == ' ')
> + src++;
> + if (!*src)
> + break;
> +
> + /* Check if this param starts with androidboot. */
> + if (strncmp(src, "androidboot.", 12) == 0) {
> + /* Copy to bootconfig (add newline if not first) */
> + if (bc_dst != androidboot_params)
> + *bc_dst++ = '\n';
> + while (*src && *src != ' ')
> + *bc_dst++ = *src++;
> + } else {
> + /* Copy to new bootargs (add space if not first) */
> + if (args_dst != new_bootargs)
> + *args_dst++ = ' ';
> + while (*src && *src != ' ')
> + *args_dst++ = *src++;
> + }
> + }
> +
> + *bc_dst++ = '\n'; /* Final newline for bootconfig */
> + *bc_dst = '\0';
> + *args_dst = '\0';
> + androidboot_params_len = bc_dst - androidboot_params;
> +
> + /* Update bootargs if we extracted any androidboot params */
> + if (androidboot_params_len > 1)
> + env_set("bootargs", new_bootargs);
> + }
> +
> + /* Map addresses for memcpy operations */
> + void *ramdisk_dest = map_sysmem(ramdisk_ptr, img_data.ramdisk_size);
> + void *vendor_ramdisk_src =
> + map_sysmem(img_data.vendor_ramdisk_ptr, img_data.vendor_ramdisk_size);
> + void *boot_ramdisk_src =
> + map_sysmem(img_data.ramdisk_ptr, img_data.boot_ramdisk_size);
We tend to declare things at the top of the function. You could split
the function if you like.
> +
> + memcpy(ramdisk_dest, vendor_ramdisk_src, img_data.vendor_ramdisk_size);
> + memcpy((char *)ramdisk_dest + img_data.vendor_ramdisk_size, boot_ramdisk_src,
> + img_data.boot_ramdisk_size);
> +
> + if (img_data.bootconfig_size) {
> + void *bootconfig_src =
> + map_sysmem(img_data.bootconfig_addr, img_data.bootconfig_size);
> + memcpy((char *)ramdisk_dest + img_data.vendor_ramdisk_size +
> + img_data.boot_ramdisk_size,
> + bootconfig_src, img_data.bootconfig_size);
> + unmap_sysmem(bootconfig_src);
> +
> + /* Add androidboot.* parameters to bootconfig */
> + if (androidboot_params && androidboot_params_len > 1) {
> + ulong bootconfig_ptr = (ulong)ramdisk_dest +
> + img_data.vendor_ramdisk_size +
> + img_data.boot_ramdisk_size;
> + bytes_added =
> + add_bootconfig_parameters(androidboot_params,
> + androidboot_params_len,
> + bootconfig_ptr,
> + img_data.bootconfig_size);
> + }
> + }
> +
> + free(androidboot_params);
> + free(new_bootargs);
> +
> + unmap_sysmem(boot_ramdisk_src);
> + unmap_sysmem(vendor_ramdisk_src);
> + unmap_sysmem(ramdisk_dest);
> + return bytes_added;
> +}
> +
> int android_image_get_ramdisk(const void *hdr, const void *vendor_boot_img,
> ulong *rd_data, ulong *rd_len)
> {
> @@ -534,17 +640,9 @@ int android_image_get_ramdisk(const void *hdr, const void *vendor_boot_img,
> ramdisk_ptr = img_data.ramdisk_addr;
> }
> *rd_data = ramdisk_ptr;
> - memcpy((void *)(ramdisk_ptr), (void *)img_data.vendor_ramdisk_ptr,
> - img_data.vendor_ramdisk_size);
> - ramdisk_ptr += img_data.vendor_ramdisk_size;
> - memcpy((void *)(ramdisk_ptr), (void *)img_data.ramdisk_ptr,
> - img_data.boot_ramdisk_size);
> - ramdisk_ptr += img_data.boot_ramdisk_size;
> - if (img_data.bootconfig_size) {
> - memcpy((void *)
> - (ramdisk_ptr), (void *)img_data.bootconfig_addr,
> - img_data.bootconfig_size);
> - }
> + if (img_data.header_version > 3)
> + img_data.ramdisk_size +=
> + android_image_set_bootconfig(hdr, vendor_boot_img, ramdisk_ptr);
> } else {
> /* Ramdisk can be used in-place, use current ptr */
> if (img_data.ramdisk_addr == 0 ||
>
> --
> 2.34.1
>
Regards,
Simon
More information about the U-Boot
mailing list