[U-Boot] [PATCH 2/2] image: Don't detect XIP images as overlapping.

Stephen Warren
2011-11-09T17:47:20Z

bootm_load_os() detects when it writes the decompressed image over
the top of the compressed image. If this happens, the original image
is corrupted. When the original image is a multi-component legacy image,
or a (potentially multi-component) FIT image, this implies that other
components may be corrupted. In turn, this means that booting is unlikely
to be successful.

However, in the case of no image compresssion coupled with an image with
load address equal to where the image is already located (e.g. an XIP
kernel, or IH_TYPE_KERNEL_ANYLOAD), there has been no copy and hence no
corruption, no matter whether it's a single-component legacy image, a
multi-component legacy image, or a FIT image. In this case, disable the
overlap detection, and allow boot to continue.

Without this change, when booting a single-component legacy image that
contains an IH_TYPE_KERNEL_ANYLOAD, bootm_load_os() would have returned
BOOTM_ERR_OVERLAP, but the caller ignores this, and boot continues and
succeeds. Now, the false error is no longer even returned.

Without this change, when booting a FIT image that contains an
IH_TYPE_KERNEL_ANYLOAD, bootm_load_os() would have returned
BOOTM_ERR_OVERLAP, which would then cause the caller to reset the board.
Now, the false error is no longer returned, and boot succeeds.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
common/cmd_bootm.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/common/cmd_bootm.c b/common/cmd_bootm.c
index 2e9df58..8f3c97f 100644
--- a/common/cmd_bootm.c
+++ b/common/cmd_bootm.c
@@ -319,6 +319,7 @@ static int bootm_load_os(image_info_t os, ulong *load_end, int boot_progress)
ulong image_start = os.image_start;
ulong image_len = os.image_len;
uint unc_len = CONFIG_SYS_BOOTM_LEN;
+ int no_overlap = 0;
#if defined(CONFIG_LZMA) || defined(CONFIG_LZO)
int ret;
#endif /* defined(CONFIG_LZMA) || defined(CONFIG_LZO) */
@@ -329,6 +330,7 @@ static int bootm_load_os(image_info_t os, ulong *load_end, int boot_progress)
case IH_COMP_NONE:
if (load == blob_start || load == image_start) {
printf(" XIP %s ... ", type_name);
+ no_overlap = 1;
} else {
printf(" Loading %s ... ", type_name);
memmove_wd((void *)load, (void *)image_start,
@@ -423,7 +425,7 @@ static int bootm_load_os(image_info_t os, ulong *load_end, int boot_progress)
if (boot_progress)
show_boot_progress(7);

- if ((load < blob_end) && (*load_end > blob_start)) {
+ if (!no_overlap && (load < blob_end) && (*load_end > blob_start)) {
debug("images.os.start = 0x%lX, images.os.end = 0x%lx\n",
blob_start, blob_end);
debug("images.os.load = 0x%lx, load_end = 0x%lx\n", load,
--
1.7.0.4