zImage-arm: Add support for booting android images

Add very basic support for booting an android image. The ramdisk and
command line from the image are only used if none has been given on
the command line.

Signed-off-by: Alban Bedel <alban.bedel@avionic-design.de>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 54 insertions, 2 deletions

diff --git a/kexec/arch/arm/kexec-zImage-arm.c b/kexec/arch/arm/kexec-zImage-arm.c
index 0ac194d..3222dd3 100644
--- a/kexec/arch/arm/kexec-zImage-arm.c
+++ b/kexec/arch/arm/kexec-zImage-arm.c
@@ -27,6 +27,23 @@ off_t initrd_base = 0, initrd_size = 0;
 unsigned int kexec_arm_image_size = 0;
 unsigned long long user_page_offset = (-1ULL);
 
+struct android_image {
+	char magic[8];
+	uint32_t kernel_size;
+	uint32_t kernel_addr;
+	uint32_t ramdisk_size;
+	uint32_t ramdisk_addr;
+	uint32_t stage2_size;
+	uint32_t stage2_addr;
+	uint32_t tags_addr;
+	uint32_t page_size;
+	uint32_t reserved1;
+	uint32_t reserved2;
+	char name[16];
+	char command_line[512];
+	uint32_t chksum[8];
+};
+
 struct tag_header {
 	uint32_t size;
 	uint32_t tag;
@@ -328,7 +345,7 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len,
 	char *modified_cmdline = NULL;
 	off_t command_line_len;
 	const char *ramdisk;
-	char *ramdisk_buf;
+	const char *ramdisk_buf;
 	int opt;
 	int use_atags;
 	char *dtb_buf;
@@ -415,6 +432,41 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len,
 	if (dtb_file)
 		dtb_buf = slurp_file(dtb_file, &dtb_length);
 
+	/* Handle android images, 2048 is the minimum page size */
+	if (len > 2048 && !strncmp(buf, "ANDROID!", 8)) {
+		const struct android_image *aimg = (const void *)buf;
+		uint32_t page_size = le32_to_cpu(aimg->page_size);
+		uint32_t kernel_size = le32_to_cpu(aimg->kernel_size);
+		uint32_t ramdisk_size = le32_to_cpu(aimg->ramdisk_size);
+		uint32_t stage2_size = le32_to_cpu(aimg->stage2_size);
+		off_t aimg_size = page_size + _ALIGN(kernel_size, page_size) +
+			_ALIGN(ramdisk_size, page_size) + stage2_size;
+
+		if (len < aimg_size) {
+			fprintf(stderr, "Android image size is incorrect\n");
+			return -1;
+		}
+
+		/* Get the kernel */
+		buf = buf + page_size;
+		len = kernel_size;
+
+		/* And the ramdisk if none was given on the command line */
+		if (!ramdisk && ramdisk_size) {
+			initrd_size = ramdisk_size;
+			ramdisk_buf = buf + _ALIGN(kernel_size, page_size);
+		}
+
+		/* Likewise for the command line */
+		if (!command_line && aimg->command_line[0]) {
+			command_line = aimg->command_line;
+			if (command_line[sizeof(aimg->command_line) - 1])
+				command_line_len = sizeof(aimg->command_line);
+			else
+				command_line_len = strlen(command_line) + 1;
+		}
+	}
+
 	/*
 	 * If we are loading a dump capture kernel, we need to update kernel
 	 * command line and also add some additional segments.
@@ -534,7 +586,7 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len,
 			initrd_base = initrd_base_new;
 		}
 
-		if (ramdisk) {
+		if (ramdisk_buf) {
 			add_segment(info, ramdisk_buf, initrd_size,
 			            initrd_base, initrd_size);