Restore the ability to continue booting after legacy image overwrite

Before new uImage code was merged, bootm code allowed for the kernel image to
get overwritten during decompresion. new uImage introduced a check for image
overwrites and refused to boot the image that got overwritten. This patch
restores the old behavior. It also adds a warning when the image overwriten is
a multi-image file, because in such case accessing componentes other than the
first one will fail.

Signed-off-by: Marian Balakowicz <m8@semihalf.com>

2 files changed, 27 insertions, 12 deletions

diff --git a/common/cmd_bootm.c b/common/cmd_bootm.c
index 9e5ce4b..3a0c83d 100644
--- a/common/cmd_bootm.c
+++ b/common/cmd_bootm.c
@@ -286,9 +286,16 @@ int do_bootm (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 		debug ("image_start = 0x%lX, image_end = 0x%lx\n", image_start, image_end);
 		debug ("load_start = 0x%lx, load_end = 0x%lx\n", load_start, load_end);
 
-		puts ("ERROR: image overwritten - must RESET the board to recover.\n");
-		show_boot_progress (-113);
-		do_reset (cmdtp, flag, argc, argv);
+		if (images.legacy_hdr_valid) {
+			if (image_get_type (&images.legacy_hdr_os_copy) == IH_TYPE_MULTI)
+				puts ("WARNING: legacy format multi component "
+					"image overwritten\n");
+		} else {
+			puts ("ERROR: new format image overwritten - "
+				"must RESET the board to recover\n");
+			show_boot_progress (-113);
+			do_reset (cmdtp, flag, argc, argv);
+		}
 	}
 
 	show_boot_progress (8);
@@ -533,9 +540,17 @@ static void *boot_get_kernel (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]
 			show_boot_progress (-5);
 			return NULL;
 		}
+
+		/*
+		 * copy image header to allow for image overwrites during kernel
+		 * decompression.
+		 */
+		memmove (&images->legacy_hdr_os_copy, hdr, sizeof(image_header_t));
+
+		/* save pointer to image header */
 		images->legacy_hdr_os = hdr;
-		images->legacy_hdr_valid = 1;
 
+		images->legacy_hdr_valid = 1;
 		show_boot_progress (6);
 		break;
 #if defined(CONFIG_FIT)
@@ -890,7 +905,7 @@ static void do_bootm_netbsd (cmd_tbl_t *cmdtp, int flag,
 	 * address of the original image header.
 	 */
 	os_hdr = NULL;
-	if (image_check_type (hdr, IH_TYPE_MULTI)) {
+	if (image_check_type (&images->legacy_hdr_os_copy, IH_TYPE_MULTI)) {
 		image_multi_getimg (hdr, 1, &kernel_data, &kernel_len);
 		if (kernel_len)
 			os_hdr = hdr;
@@ -947,7 +962,7 @@ static void do_bootm_lynxkdi (cmd_tbl_t *cmdtp, int flag,
 			     int argc, char *argv[],
 			     bootm_headers_t *images)
 {
-	image_header_t *hdr = images->legacy_hdr_os;
+	image_header_t *hdr = &images->legacy_hdr_os_copy;
 
 #if defined(CONFIG_FIT)
 	if (!images->legacy_hdr_valid) {
@@ -964,7 +979,7 @@ static void do_bootm_rtems (cmd_tbl_t *cmdtp, int flag,
 			   int argc, char *argv[],
 			   bootm_headers_t *images)
 {
-	image_header_t *hdr = images->legacy_hdr_os;
+	image_header_t *hdr = &images->legacy_hdr_os_copy;
 	void (*entry_point)(bd_t *);
 
 #if defined(CONFIG_FIT)
@@ -994,10 +1009,10 @@ static void do_bootm_vxworks (cmd_tbl_t *cmdtp, int flag,
 			     bootm_headers_t *images)
 {
 	char str[80];
-	image_header_t *hdr = images->legacy_hdr_os;
+	image_header_t *hdr = &images->legacy_hdr_os_copy;
 
 #if defined(CONFIG_FIT)
-	if (hdr == NULL) {
+	if (!images->legacy_hdr_valid) {
 		fit_unsupported_reset ("VxWorks");
 		do_reset (cmdtp, flag, argc, argv);
 	}
@@ -1014,7 +1029,7 @@ static void do_bootm_qnxelf(cmd_tbl_t *cmdtp, int flag,
 {
 	char *local_args[2];
 	char str[16];
-	image_header_t *hdr = images->legacy_hdr_os;
+	image_header_t *hdr = &images->legacy_hdr_os_copy;
 
 #if defined(CONFIG_FIT)
 	if (!images->legacy_hdr_valid) {
@@ -1041,7 +1056,7 @@ static void do_bootm_artos (cmd_tbl_t *cmdtp, int flag,
 	int i, j, nxt, len, envno, envsz;
 	bd_t *kbd;
 	void (*entry)(bd_t *bd, char *cmdline, char **fwenv, ulong top);
-	image_header_t *hdr = images->legacy_hdr_os;
+	image_header_t *hdr = &images->legacy_hdr_os_copy;
 
 #if defined(CONFIG_FIT)
 	if (!images->legacy_hdr_valid) {
diff --git a/common/image.c b/common/image.c
index 9e63432..d218f2f 100644
--- a/common/image.c
+++ b/common/image.c
@@ -983,7 +983,7 @@ int boot_get_ramdisk (int argc, char *argv[], bootm_headers_t *images,
 #endif /* CONFIG_B2 || CONFIG_EVB4510 || CONFIG_ARMADILLO */
 
 	} else if (images->legacy_hdr_valid &&
-			image_check_type (images->legacy_hdr_os, IH_TYPE_MULTI)) {
+			image_check_type (&images->legacy_hdr_os_copy, IH_TYPE_MULTI)) {
 		/*
 		 * Now check if we have a legacy mult-component image,
 		 * get second entry data start address and len.