[PATCH v3 3/5] boot: android: Add bootconfig support
Guillaume La Roque
glaroque at baylibre.com
Mon Nov 24 11:14:11 CET 2025
Hi Simon,
thanks for review.
Le 19/11/2025 à 14:17, Simon Glass a écrit :
> 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 ?
i will do
>
>> +{
>> + /* 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.
agree with you
>
>> + 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.
i will create a sub function for copying data.
>
>> +
>> + 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
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