image: android: handle ramdisk default address

The two tools that create android boot images, mkbootimg and the fastboot
client, set the kernel address by default to 0x11008000.

U-boot always honors this field, and will try to copy the ramdisk to
whatever value is set in the header, which won't be mapped to the actual
RAM on most platforms, resulting in the kernel obviously not booting.

All the targets in U-Boot right now will download the android boot image
to CONFIG_SYS_LOAD_ADDR, which means that it will already have been
downloaded to some location that is suitable to use the ramdisk in-place
for header version 0 to 2. For header version 3 and later, the ramdisk
can't be used in-place to use ramdisk_addr_r in this case.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Tested-by: Guillaume La Roque <glaroque@baylibre.com>
Link: https://lore.kernel.org/r/20241017-topic-fastboot-fixes-mkbootimg-v2-3-c3927102d931@linaro.org
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>

1 files changed, 30 insertions, 8 deletions

diff --git a/boot/image-android.c b/boot/image-android.c
index 3adcc69a392..cd01278f211 100644
--- a/boot/image-android.c
+++ b/boot/image-android.c
@@ -14,6 +14,7 @@
 #include <linux/libfdt.h>
 
 #define ANDROID_IMAGE_DEFAULT_KERNEL_ADDR	0x10008000
+#define ANDROID_IMAGE_DEFAULT_RAMDISK_ADDR	0x11000000
 
 static char andr_tmp_str[ANDR_BOOT_ARGS_SIZE + 1];
 
@@ -405,9 +406,25 @@ int android_image_get_ramdisk(const void *hdr, const void *vendor_boot_img,
 
 	if (!img_data.ramdisk_size)
 		return -ENOENT;
-
+	/*
+	 * Android tools can generate a boot.img with default load address
+	 * or 0, even though it doesn't really make a lot of sense, and it
+	 * might be valid on some platforms, we treat that address as
+	 * the default value for this field, and try to pass ramdisk
+	 * in place if possible.
+	 */
 	if (img_data.header_version > 2) {
-		ramdisk_ptr = img_data.ramdisk_addr;
+		/* Ramdisk can't be used in-place, copy it to ramdisk_addr_r */
+		if (img_data.ramdisk_addr == ANDROID_IMAGE_DEFAULT_RAMDISK_ADDR) {
+			ramdisk_ptr = env_get_ulong("ramdisk_addr_r", 16, 0);
+			if (!ramdisk_ptr) {
+				printf("Invalid ramdisk_addr_r to copy ramdisk into\n");
+				return -EINVAL;
+			}
+		} else {
+			ramdisk_ptr = img_data.ramdisk_addr;
+		}
+		*rd_data = ramdisk_ptr;
 		memcpy((void *)(ramdisk_ptr), (void *)img_data.vendor_ramdisk_ptr,
 		       img_data.vendor_ramdisk_size);
 		ramdisk_ptr += img_data.vendor_ramdisk_size;
@@ -420,15 +437,20 @@ int android_image_get_ramdisk(const void *hdr, const void *vendor_boot_img,
 			       img_data.bootconfig_size);
 		}
 	} else {
-		ramdisk_ptr = img_data.ramdisk_addr;
-		memcpy((void *)(ramdisk_ptr), (void *)img_data.ramdisk_ptr,
-		       img_data.ramdisk_size);
+		/* Ramdisk can be used in-place, use current ptr */
+		if (img_data.ramdisk_addr == 0 ||
+		    img_data.ramdisk_addr == ANDROID_IMAGE_DEFAULT_RAMDISK_ADDR) {
+			*rd_data = img_data.ramdisk_ptr;
+		} else {
+			ramdisk_ptr = img_data.ramdisk_addr;
+			*rd_data = ramdisk_ptr;
+			memcpy((void *)(ramdisk_ptr), (void *)img_data.ramdisk_ptr,
+			       img_data.ramdisk_size);
+		}
 	}
 
 	printf("RAM disk load addr 0x%08lx size %u KiB\n",
-	       img_data.ramdisk_addr, DIV_ROUND_UP(img_data.ramdisk_size, 1024));
-
-	*rd_data = img_data.ramdisk_addr;
+	       *rd_data, DIV_ROUND_UP(img_data.ramdisk_size, 1024));
 
 	*rd_len = img_data.ramdisk_size;
 	return 0;