Commit 05227490 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Steven Rostedt (VMware)
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docs: bootconfig: Add the endianness of fields

Add a description about the endianness of the size and the checksum
fields. Those must be stored as le32 instead of u32. This will allow
us to apply bootconfig to the cross build initrd without caring
the endianness.

Link: https://lkml.kernel.org/r/160583936246.547349.10964204130590955409.stgit@devnote2



Reported-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Suggested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent e8684358
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+3 −1
Original line number Diff line number Diff line
@@ -140,7 +140,9 @@ Since the boot configuration file is loaded with initrd, it will be added
to the end of the initrd (initramfs) image file with padding, size,
checksum and 12-byte magic word as below.

[initrd][bootconfig][padding][size(u32)][checksum(u32)][#BOOTCONFIG\n]
[initrd][bootconfig][padding][size(le32)][checksum(le32)][#BOOTCONFIG\n]

The size and checksum fields are unsigned 32bit little endian value.

When the boot configuration is added to the initrd image, the total
file size is aligned to 4 bytes. To fill the gap, null characters