bootstd: android: don't read whole partition sizes

The current implementation is reading the whole partition for boot and
vendor_boot image which can be long following the size of the
partition or the time to read blocks (driver/SoC specific).

For example with mediatek mt8365 EVK board, we have a 64MiB boot
partition and the boot image flashed in this partition is only 42MiB.
It takes ~8-9 secs to read the boot partition.

Instead we can retrieved the boot image and vendor boot image size
with these new functions:
- android_image_get_bootimg_size
- android_image_get_vendor_bootimg_size
Use these information and read only the necessary.

By doing this with mt8365 EVK board, we read boot image in ~5 secs.

Signed-off-by: Julien Masson <jmasson@baylibre.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/20241121-bootmeth-android-part-sizes-v1-1-25760bbd0f08@baylibre.com
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>

1 files changed, 45 insertions, 0 deletions

diff --git a/boot/image-android.c b/boot/image-android.c
index cd01278f211..93b54bf8d79 100644
--- a/boot/image-android.c
+++ b/boot/image-android.c
@@ -178,6 +178,51 @@ static void android_boot_image_v0_v1_v2_parse_hdr(const struct andr_boot_img_hdr
 	data->boot_img_total_size = end - (ulong)hdr;
 }
 
+bool android_image_get_bootimg_size(const void *hdr, u32 *boot_img_size)
+{
+	struct andr_image_data data;
+
+	if (!hdr || !boot_img_size) {
+		printf("hdr or boot_img_size can't be NULL\n");
+		return false;
+	}
+
+	if (!is_android_boot_image_header(hdr)) {
+		printf("Incorrect boot image header\n");
+		return false;
+	}
+
+	if (((struct andr_boot_img_hdr_v0 *)hdr)->header_version <= 2)
+		android_boot_image_v0_v1_v2_parse_hdr(hdr, &data);
+	else
+		android_boot_image_v3_v4_parse_hdr(hdr, &data);
+
+	*boot_img_size = data.boot_img_total_size;
+
+	return true;
+}
+
+bool android_image_get_vendor_bootimg_size(const void *hdr, u32 *vendor_boot_img_size)
+{
+	struct andr_image_data data;
+
+	if (!hdr || !vendor_boot_img_size) {
+		printf("hdr or vendor_boot_img_size can't be NULL\n");
+		return false;
+	}
+
+	if (!is_android_vendor_boot_image_header(hdr)) {
+		printf("Incorrect vendor boot image header\n");
+		return false;
+	}
+
+	android_vendor_boot_image_v3_v4_parse_hdr(hdr, &data);
+
+	*vendor_boot_img_size = data.vendor_boot_img_total_size;
+
+	return true;
+}
+
 bool android_image_get_data(const void *boot_hdr, const void *vendor_boot_hdr,
 			    struct andr_image_data *data)
 {