MIPS: zboot: put appended dtb into a section

This will make a separated section for dtb appear in ELF, and we can
then use objcopy to patch a dtb into vmlinuz when RAW_APPENDED_DTB
is set in kernel config.

command to patch a dtb:
objcopy --set-section-flags=.appended_dtb=alloc,contents \
--update-section=.appended_dtb=<target>.dtb vmlinuz

Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: Add support for vmlinuz.bin appended dtb

Add support for detecting a vmlinuz.bin appended dtb and overriding
the boot arguments to match the UHI interface.

To ensure _edata / __apendend_dtb points to the actual end of the
binary, align the data section to 16 bytes instead of the address
cursor.

Due to ld.script not going through the preprocessor, we can't check
for MIPS_ZBOOT_APPENDED_DTB being enabled, so always reserve space
for it. It should have no consequences for booting without it enabled
except 1 MiB more ram usage during the uncompressing stage.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: John Crispin <blogic@openwrt.org>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: James Hartley <James.Hartley@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/9741/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: ZBOOT: Define program header for text loadable segment

There is currently no corresponding ELF program header for the "text"
loadable segment which is confusing for some bootloader out there such
as CFE because it expects to find a program header matching the segment
it is trying to load. The Linux kernel ELF binary "vmlinux" has a
similar program header for the text segment so we just mimic this here
too.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: blogic@openwrt.org
Cc: james.hogan@imgtec.com
Patchwork: https://patchwork.linux-mips.org/patch/5827/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Clean up arch/mips/boot/compressed/ld.script

- Remove unused symbols: _fdata, _text; only _edata and _end are needed by
head.S
- Remove unused sections: .sbss, .stab, .gptab.sdata, .gptab.sbss
- Change the alignment to 16 bytes to ensure it is greater than any
fundamental type of a MIPS compiler.
- Clean up comments

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1381/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Cleanup and Fixup of compressed kernel support

o Remove the .initrd section. The initrd section was already handled
when vmlinux was linked.
o Discard .MIPS.options, .options, .pdr, .reginfo, .comment and .note
sections. If .MIPS.options is not removed, kernels compiled with gcc
3.4.6 will not boot.
o Clean up the file format.
o Remove several other unneeded sections.

Tested with GCC 3.4.6 and 4.4.1 with and without initrd.

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/785/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Add support for GZIP / BZIP2 / LZMA compressed kernel images

This patch helps to generate smaller kernel images for linux-MIPS,

Here is the effect when using lzma:

$ ls -sh vmlinux
7.1M vmlinux
$ ls -sh vmlinuz
1.5M vmlinuz

Have tested the 32bit kernel on Qemu/Malta and 64bit kernel on FuLoong
Mini PC. both of them work well. and also, tested by Alexander Clouter
on an AR7 based Linksys WAG54Gv2, and by Manuel Lauss on an Alchemy
board.

This -v2 version incorporate the feedback from Ralf, and add the
following changes:

1. add .ecoff, .bin, .erec format support
2. only enable it and the debug source code for the machines we tested
3. a dozen of fixups and cleanups

and if you want to enable it for your board, please try to select
SYS_SUPPORTS_ZBOOT for it, and if the board have an 16550 compatible
uart, you can select SYS_SUPPORTS_ZBOOT_UART16550 directly. and then
sending the relative patches to Ralf.

Tested-by: Manuel Lauss <manuel.lauss@googlemail.com>
Tested-by: Alexander Clouter <alex@digriz.org.uk>
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>