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>

4 files changed, 122 insertions, 6 deletions

diff --git a/common/Makefile b/common/Makefile
index 7c853ae..bfcb466 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -237,6 +237,7 @@ obj-y += console.o
 obj-$(CONFIG_CROS_EC) += cros_ec.o
 obj-y += dlmalloc.o
 obj-y += image.o
+obj-$(CONFIG_ANDROID_BOOT_IMAGE) += image-android.o
 obj-$(CONFIG_OF_LIBFDT) += image-fdt.o
 obj-$(CONFIG_FIT) += image-fit.o
 obj-$(CONFIG_FIT_SIGNATURE) += image-sig.o
diff --git a/common/cmd_bootm.c b/common/cmd_bootm.c
index c243a5b..993b906 100644
--- a/common/cmd_bootm.c
+++ b/common/cmd_bootm.c
@@ -222,6 +222,7 @@ static int bootm_find_os(cmd_tbl_t *cmdtp, int flag, int argc,
 			 char * const argv[])
 {
 	const void *os_hdr;
+	bool ep_found = false;
 
 	/* get kernel image header, start address and length */
 	os_hdr = boot_get_kernel(cmdtp, flag, argc, argv,
@@ -274,6 +275,18 @@ static int bootm_find_os(cmd_tbl_t *cmdtp, int flag, int argc,
 		}
 		break;
 #endif
+#ifdef CONFIG_ANDROID_BOOT_IMAGE
+	case IMAGE_FORMAT_ANDROID:
+		images.os.type = IH_TYPE_KERNEL;
+		images.os.comp = IH_COMP_NONE;
+		images.os.os = IH_OS_LINUX;
+		images.ep = images.os.load;
+		ep_found = true;
+
+		images.os.end = android_image_get_end(os_hdr);
+		images.os.load = android_image_get_kload(os_hdr);
+		break;
+#endif
 	default:
 		puts("ERROR: unknown image format type!\n");
 		return 1;
@@ -293,7 +306,7 @@ static int bootm_find_os(cmd_tbl_t *cmdtp, int flag, int argc,
 			return 1;
 		}
 #endif
-	} else {
+	} else if (!ep_found) {
 		puts("Could not find kernel entry point!\n");
 		return 1;
 	}
@@ -1002,6 +1015,14 @@ static const void *boot_get_kernel(cmd_tbl_t *cmdtp, int flag, int argc,
 		images->fit_noffset_os = os_noffset;
 		break;
 #endif
+#ifdef CONFIG_ANDROID_BOOT_IMAGE
+	case IMAGE_FORMAT_ANDROID:
+		printf("## Booting Android Image at 0x%08lx ...\n", img_addr);
+		if (android_image_get_kernel((void *)img_addr, images->verify,
+					     os_data, os_len))
+			return NULL;
+		break;
+#endif
 	default:
 		printf("Wrong Image Format for %s command\n", cmdtp->name);
 		bootstage_error(BOOTSTAGE_ID_FIT_KERNEL_INFO);
diff --git a/common/image-android.c b/common/image-android.c
new file mode 100644
index 0000000..6ded7e2
--- /dev/null
+++ b/common/image-android.c
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2011 Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <image.h>
+#include <android_image.h>
+
+static char andr_tmp_str[ANDR_BOOT_ARGS_SIZE + 1];
+
+int android_image_get_kernel(const struct andr_img_hdr *hdr, int verify,
+			     ulong *os_data, ulong *os_len)
+{
+	/*
+	 * Not all Android tools use the id field for signing the image with
+	 * sha1 (or anything) so we don't check it. It is not obvious that the
+	 * string is null terminated so we take care of this.
+	 */
+	strncpy(andr_tmp_str, hdr->name, ANDR_BOOT_NAME_SIZE);
+	andr_tmp_str[ANDR_BOOT_NAME_SIZE] = '\0';
+	if (strlen(andr_tmp_str))
+		printf("Android's image name: %s\n", andr_tmp_str);
+
+	printf("Kernel load addr 0x%08x size %u KiB\n",
+	       hdr->kernel_addr, DIV_ROUND_UP(hdr->kernel_size, 1024));
+	strncpy(andr_tmp_str, hdr->cmdline, ANDR_BOOT_ARGS_SIZE);
+	andr_tmp_str[ANDR_BOOT_ARGS_SIZE] = '\0';
+	if (strlen(andr_tmp_str)) {
+		printf("Kernel command line: %s\n", andr_tmp_str);
+		setenv("bootargs", andr_tmp_str);
+	}
+	if (hdr->ramdisk_size)
+		printf("RAM disk load addr 0x%08x size %u KiB\n",
+		       hdr->ramdisk_addr,
+		       DIV_ROUND_UP(hdr->ramdisk_size, 1024));
+
+	if (os_data) {
+		*os_data = (ulong)hdr;
+		*os_data += hdr->page_size;
+	}
+	if (os_len)
+		*os_len = hdr->kernel_size;
+	return 0;
+}
+
+int android_image_check_header(const struct andr_img_hdr *hdr)
+{
+	return memcmp(ANDR_BOOT_MAGIC, hdr->magic, ANDR_BOOT_MAGIC_SIZE);
+}
+
+ulong android_image_get_end(const struct andr_img_hdr *hdr)
+{
+	u32 size = 0;
+	/*
+	 * The header takes a full page, the remaining components are aligned
+	 * on page boundary
+	 */
+	size += hdr->page_size;
+	size += ALIGN(hdr->kernel_size, hdr->page_size);
+	size += ALIGN(hdr->ramdisk_size, hdr->page_size);
+	size += ALIGN(hdr->second_size, hdr->page_size);
+
+	return size;
+}
+
+ulong android_image_get_kload(const struct andr_img_hdr *hdr)
+{
+	return hdr->kernel_addr;
+}
+
+int android_image_get_ramdisk(const struct andr_img_hdr *hdr,
+			      ulong *rd_data, ulong *rd_len)
+{
+	if (!hdr->ramdisk_size)
+		return -1;
+	*rd_data = (unsigned long)hdr;
+	*rd_data += hdr->page_size;
+	*rd_data += ALIGN(hdr->kernel_size, hdr->page_size);
+
+	*rd_len = hdr->ramdisk_size;
+	return 0;
+}
diff --git a/common/image.c b/common/image.c
index 9c6bec5..7ff27d7 100644
--- a/common/image.c
+++ b/common/image.c
@@ -659,10 +659,12 @@ int genimg_get_format(const void *img_addr)
 	if (image_check_magic(hdr))
 		format = IMAGE_FORMAT_LEGACY;
 #if defined(CONFIG_FIT) || defined(CONFIG_OF_LIBFDT)
-	else {
-		if (fdt_check_header(img_addr) == 0)
-			format = IMAGE_FORMAT_FIT;
-	}
+	else if (fdt_check_header(img_addr) == 0)
+		format = IMAGE_FORMAT_FIT;
+#endif
+#ifdef CONFIG_ANDROID_BOOT_IMAGE
+	else if (android_image_check_header(img_addr) == 0)
+		format = IMAGE_FORMAT_ANDROID;
 #endif
 
 	return format;
@@ -932,7 +934,15 @@ int boot_get_ramdisk(int argc, char * const argv[], bootm_headers_t *images,
 				(ulong)images->legacy_hdr_os);
 
 		image_multi_getimg(images->legacy_hdr_os, 1, &rd_data, &rd_len);
-	} else {
+	}
+#ifdef CONFIG_ANDROID_BOOT_IMAGE
+	else if ((genimg_get_format(images) == IMAGE_FORMAT_ANDROID) &&
+		 (!android_image_get_ramdisk((void *)images->os.start,
+		 &rd_data, &rd_len))) {
+		/* empty */
+	}
+#endif
+	else {
 		/*
 		 * no initrd image
 		 */