doc: Add a note about producing 'md.b' output using hexdump
Comparing a hex dump on the U-Boot command line with the contents of a
file on the host system is fairly easy and convenient to do manually if
it is small. But the format used hexdump by default differs from that
shown by U-Boot. Add a note about how to make them the same.
(For large dumps, writing the data to the network with tftpput, or to a
USB stick with ext4save is easiest.)
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/doc/usage/md.rst b/doc/usage/md.rst
index 3951b0d..4c1073e 100644
--- a/doc/usage/md.rst
+++ b/doc/usage/md.rst
@@ -39,6 +39,16 @@
number of values to dump. Defaults to 40 (0d64). Note that this is not
the same as the number of bytes, unless .b is used.
+Note that the format of 'md.b' can be emulated from linux with::
+
+ # This works but requires using sed to get the extra spaces
+ # <addr> is the address, <f> is the filename
+ xxd -o <addr> -g1 <f> |sed 's/ / /' >bad
+
+ # This uses a single tool but the offset always starts at 0
+ # <f> is the filename
+ hexdump -v -e '"%08.8_ax: " 16/1 "%02x " " "' -e '16/1 "%_p" "\n" ' <f>
+
Example
-------