image: add support for Android's boot image format

This patch adds support for the Android boot-image format. The header
file is from the Android project and got slightly alterted so the struct +
its defines are not generic but have something like a namespace. The
header file is from bootloader/legacy/include/boot/bootimg.h. The header
parsing has been written from scratch and I looked at
bootloader/legacy/usbloader/usbloader.c for some details.
The image contains the physical address (load address) of the kernel and
ramdisk. This address is considered only for the kernel image.
The "second image" defined in the image header is currently not
supported. I haven't found anything that is creating this.

v3 (Rob Herring):
This is based on http://patchwork.ozlabs.org/patch/126797/ with the
following changes:
- Rebased to current mainline
- Moved android image handling to separate functions in
  common/image-android.c
- s/u8/char/ in header to fix string function warnings
- Use SPDX identifiers for licenses
- Cleaned-up file source information:
  android_image.h is from file include/boot/bootimg.h in repository:
  https://android.googlesource.com/platform/bootable/bootloader/legacy
  The git commit hash is 4205b865141ff2e255fe1d3bd16de18e217ef06a
  usbloader.c would be from the same commit, but it does not appear
  to have been used for any actual code.
v4:
- s/andriod/android/
- Use a separate flag ep_found to track if the entry point has been set
rather than using a magic value.

Cc: Wolfgang Denk <wd@denx.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Tom Rini <trini@ti.com>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
diff --git a/include/image.h b/include/image.h
index 2508d7d..e1f9297 100644
--- a/include/image.h
+++ b/include/image.h
@@ -412,6 +412,7 @@
 #define IMAGE_FORMAT_INVALID	0x00
 #define IMAGE_FORMAT_LEGACY	0x01	/* legacy image_header based format */
 #define IMAGE_FORMAT_FIT	0x02	/* new, libfdt based format */
+#define IMAGE_FORMAT_ANDROID	0x03	/* Android boot image */
 
 int genimg_get_format(const void *img_addr);
 int genimg_has_config(bootm_headers_t *images);
@@ -1030,4 +1031,16 @@
 #endif /* CONFIG_FIT_VERBOSE */
 #endif /* CONFIG_FIT */
 
+#if defined(CONFIG_ANDROID_BOOT_IMAGE)
+struct andr_img_hdr;
+int android_image_check_header(const struct andr_img_hdr *hdr);
+int android_image_get_kernel(const struct andr_img_hdr *hdr, int verify,
+			     ulong *os_data, ulong *os_len);
+int android_image_get_ramdisk(const struct andr_img_hdr *hdr,
+			      ulong *rd_data, ulong *rd_len);
+ulong android_image_get_end(const struct andr_img_hdr *hdr);
+ulong android_image_get_kload(const struct andr_img_hdr *hdr);
+
+#endif /* CONFIG_ANDROID_BOOT_IMAGE */
+
 #endif	/* __IMAGE_H__ */