[U-Boot] [PATCH 1/2] image: android: allow booting lz4-compressed kernels

[Marek Vasut]

On 4/3/19 11:35 PM, Eugeniu Rosca wrote:
> According to Android image format [1], kernel image resides at 1 page
> offset from the boot image address. Grab the magic number from there
> and allow U-Boot to handle LZ4-compressed KNL binaries instead of
> hardcoding compression type to IH_COMP_NONE. Other compression types,
> if needed, can be added later.
> 
> Tested on H3ULCB-KF using the image detailed in [2].
> 
> [1] Excerpt from include/android_image.h
>     +-----------------+
>     | boot header     | 1 page
>     +-----------------+
>     | kernel          | n pages
>     +-----------------+
>     | ramdisk         | m pages
>     +-----------------+
>     | second stage    | o pages
>     +-----------------+
> 
> [2] => iminfo 4c000000
>     ## Checking Image at 4c000000 ...
>     Android image found
>     kernel size:      85b9d1
>     kernel address:   48080000
>     ramdisk size:     54ddbc
>     ramdisk addrress: 4a180000
>     second size:      0
>     second address:   48000800
>     tags address:     48000100
>     page size:        800
>     os_version:       1200012a (ver: 0.9.0, level: 2018.10)
>     name:
>     cmdline:          buildvariant=userdebug
> 
> Signed-off-by: Eugeniu Rosca <erosca at de.adit-jv.com>
> ---
>  common/bootm.c         |  2 +-
>  common/image-android.c | 14 ++++++++++++++
>  include/image.h        |  1 +
>  3 files changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/common/bootm.c b/common/bootm.c
> index 3adbceaa38e3..bbae66df1001 100644
> --- a/common/bootm.c
> +++ b/common/bootm.c
> @@ -154,7 +154,7 @@ static int bootm_find_os(cmd_tbl_t *cmdtp, int flag, int argc,
>  #ifdef CONFIG_ANDROID_BOOT_IMAGE
>  	case IMAGE_FORMAT_ANDROID:
>  		images.os.type = IH_TYPE_KERNEL;
> -		images.os.comp = IH_COMP_NONE;
> +		images.os.comp = android_image_get_kcomp(os_hdr);
>  		images.os.os = IH_OS_LINUX;
>  
>  		images.os.end = android_image_get_end(os_hdr);
> diff --git a/common/image-android.c b/common/image-android.c
> index 2f38c191e911..eec8c4decdbd 100644
> --- a/common/image-android.c
> +++ b/common/image-android.c
> @@ -126,6 +126,20 @@ ulong android_image_get_kload(const struct andr_img_hdr *hdr)
>  	return android_image_get_kernel_addr(hdr);
>  }
>  
> +#define LZ4F_MAGIC 0x184D2204

Don't we already have this magic in some common header ?

> +ulong android_image_get_kcomp(const struct andr_img_hdr *hdr)
> +{
> +	u32 *magic = (u32 *)((ulong)hdr + hdr->page_size);

Should this be get_unaligned((uintptr_t)hdr + hdr->page_size) ?
get_unaligned() because the image may be at unaligned address (although
that's unlikely) and uintptr_t to cater for both 32 and 64bit pointers.

> +	switch (le32_to_cpu(*magic)) {
> +	case LZ4F_MAGIC:
> +		return IH_COMP_LZ4;
> +	default:
> +		return IH_COMP_NONE;
> +	}
> +}
> +
>  int android_image_get_ramdisk(const struct andr_img_hdr *hdr,
>  			      ulong *rd_data, ulong *rd_len)
>  {
> diff --git a/include/image.h b/include/image.h
> index 765ffecee0a7..572034afd8c3 100644
> --- a/include/image.h
> +++ b/include/image.h
> @@ -1312,6 +1312,7 @@ int android_image_get_second(const struct andr_img_hdr *hdr,
>  			      ulong *second_data, ulong *second_len);
>  ulong android_image_get_end(const struct andr_img_hdr *hdr);
>  ulong android_image_get_kload(const struct andr_img_hdr *hdr);
> +ulong android_image_get_kcomp(const struct andr_img_hdr *hdr);
>  void android_print_contents(const struct andr_img_hdr *hdr);
>  
>  #endif /* CONFIG_ANDROID_BOOT_IMAGE */
> 


-- 
Best regards,
Marek Vasut