[PATCH v2 3/5] boot: android: Add bootconfig support
Guillaume La Roque
glaroque at baylibre.com
Mon Nov 3 19:52:15 CET 2025
Hi,
Le 31/10/2025 à 16:58, Mattijs Korpershoek a écrit :
> Hi Guillaume,
>
> Thank you for the patch.
>
> On Fri, Oct 17, 2025 at 15:19, "Guillaume La Roque (TI.com)"<glaroque at baylibre.com> wrote:
>
>> For android vendor boot image version 4 bootconfig is mandatory.[1]
> There seems to be a link "[1]" here but it's not part of the commit
> message.
> Can you add it please?
yes of course ,
>> 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.
>>
>> Signed-off-by: Guillaume La Roque (TI.com)<glaroque at baylibre.com>
>> ---
>> boot/image-android.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++----
>> 1 file changed, 93 insertions(+), 8 deletions(-)
>>
>> diff --git a/boot/image-android.c b/boot/image-android.c
>> index 613f2aa4b9e..cf038a4a62f 100644
>> --- a/boot/image-android.c
>> +++ b/boot/image-android.c
>> @@ -534,17 +534,102 @@ 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,
>> +
>> + /* 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;
>> +
>> + 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);
>> +
>> + memcpy(ramdisk_dest, vendor_ramdisk_src,
>> 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;
>> + memcpy((char *)ramdisk_dest + img_data.vendor_ramdisk_size,
>> + boot_ramdisk_src, img_data.boot_ramdisk_size);
>> +
>> if (img_data.bootconfig_size) {
>> - memcpy((void *)
>> - (ramdisk_ptr), (void *)img_data.bootconfig_addr,
>> - 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;
>> + img_data.ramdisk_size +=
>> + 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);
> We are here in the "if (img_data.header_version > 2) {" block.
> What about boot image v3? Why are we forcing bootconfig upon them?
our right it's not good bootconfig come with version 4 i will fix it in v3.
>
> Also, please move this to a seperate function. It makes
> android_image_get_ramdisk() quite long and difficult to read otherwise.
i will.
>
> Finally, what happens if a kernel does not have bootconfig enabled ?
> I imagine that everything will crash due to this change. Even if
> bootconfig is mandatory for boot image v4, I believe we should make this
> behaviour optional to avoid breaking existing kernels.
it's enable in android kernel since android-12-5.4.xx so if you enable
boot image version 4 and move androidboot.x in booconfig instead of
kernelcmdline it's because you decide to enable it with
BOARD_KERNEL_CMDLINE += bootconfig and you support android boot image
version 4. it's explained in aosp doc
:https://source.android.com/docs/core/architecture/bootloader/implementing-bootconfig
>
>> } else {
>> /* Ramdisk can be used in-place, use current ptr */
>> if (img_data.ramdisk_addr == 0 ||
>>
>> --
>> 2.34.1
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