[PATCH v2 2/2] bootm: add support for booting compressed images

[Lucas Stach]

ARM64 does not have a self extracting image format, but relies on the image
being externally compressed with one of the standard compression algorithms.

Add support for decompressing the bootm OS image. It is added in common
code as it may also be useful for other images/architectures.

Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
---
v2: Add proper error handling if nested bootm fails.
---
 common/bootm.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)

diff --git a/common/bootm.c b/common/bootm.c
index 092116beb94a..f5c0e5184b0a 100644
--- a/common/bootm.c
+++ b/common/bootm.c
@@ -12,6 +12,7 @@
 #include <environment.h>
 #include <linux/stat.h>
 #include <magicvar.h>
+#include <uncompress.h>
 
 static LIST_HEAD(handler_list);
 
@@ -808,6 +809,86 @@ err_out:
 	return ret;
 }
 
+static int do_bootm_compressed(struct image_data *img_data)
+{
+	struct bootm_data bootm_data = {
+		.oftree_file = img_data->oftree_file,
+		.initrd_file = img_data->initrd_file,
+		.tee_file = img_data->tee_file,
+		.verbose = img_data->verbose,
+		.verify = img_data->verify,
+		.force = img_data->force,
+		.dryrun = img_data->dryrun,
+		.initrd_address = img_data->initrd_address,
+		.os_address = img_data->os_address,
+		.os_entry = img_data->os_entry,
+	};
+	int from, to, ret;
+	char *dstpath;
+
+	from = open(img_data->os_file, O_RDONLY);
+	if (from < 0)
+		return -ENODEV;
+
+	dstpath = make_temp("bootm-compressed");
+	if (!dstpath) {
+		ret = -ENOMEM;
+		goto fail_from;
+	}
+
+	to = open(dstpath, O_CREAT | O_WRONLY);
+	if (to < 0) {
+		ret = -ENODEV;
+		goto fail_make_temp;
+	}
+
+	ret = uncompress_fd_to_fd(from, to, uncompress_err_stdout);
+	if (ret)
+		goto fail_to;
+
+	bootm_data.os_file = dstpath;
+	ret = bootm_boot(&bootm_data);
+
+fail_to:
+	close(to);
+	unlink(dstpath);
+fail_make_temp:
+	free(dstpath);
+fail_from:
+	close(from);
+	return ret;
+}
+
+static struct image_handler bzip2_bootm_handler = {
+	.name = "BZIP2 compressed file",
+	.bootm = do_bootm_compressed,
+	.filetype = filetype_bzip2,
+};
+
+static struct image_handler gzip_bootm_handler = {
+	.name = "GZIP compressed file",
+	.bootm = do_bootm_compressed,
+	.filetype = filetype_gzip,
+};
+
+static struct image_handler lzo_bootm_handler = {
+	.name = "LZO compressed file",
+	.bootm = do_bootm_compressed,
+	.filetype = filetype_lzo_compressed,
+};
+
+static struct image_handler lz4_bootm_handler = {
+	.name = "LZ4 compressed file",
+	.bootm = do_bootm_compressed,
+	.filetype = filetype_lz4_compressed,
+};
+
+static struct image_handler xz_bootm_handler = {
+	.name = "XZ compressed file",
+	.bootm = do_bootm_compressed,
+	.filetype = filetype_xz_compressed,
+};
+
 static int bootm_init(void)
 {
 	globalvar_add_simple("bootm.image", NULL);
@@ -830,6 +911,18 @@ static int bootm_init(void)
 	globalvar_add_simple_enum("bootm.verify", (unsigned int *)&bootm_verify_mode,
 				  bootm_verify_names, ARRAY_SIZE(bootm_verify_names));
 
+
+	if (IS_ENABLED(CONFIG_BZLIB))
+		register_image_handler(&bzip2_bootm_handler);
+	if (IS_ENABLED(CONFIG_ZLIB))
+		register_image_handler(&gzip_bootm_handler);
+	if (IS_ENABLED(CONFIG_LZO_DECOMPRESS))
+		register_image_handler(&lzo_bootm_handler);
+	if (IS_ENABLED(CONFIG_LZ4_DECOMPRESS))
+		register_image_handler(&lz4_bootm_handler);
+	if (IS_ENABLED(CONFIG_XZ_DECOMPRESS))
+		register_image_handler(&xz_bootm_handler);
+
 	return 0;
 }
 late_initcall(bootm_init);
-- 
2.29.2