Re: [PATCH] MIPS: add U-boot uImage build target to arch Makefile

[Sergey Kvachonok <ravenexp@gmail.com>]

On Mon, Jan 17, 2011 at 6:34 PM, wu zhangjin <wuzhangjin@gmail.com> wrote:

> Just a friendly reminder: no need to add the algo options in Kconfig
> for we already have them in init/Kconfig, you can search LZMA, BZIP2
> ... there.

No, I don't have these since my platform (jz4740) does not define
SYS_SUPPORTS_ZBOOT. I don't know whether SFX-style compressed kernels
work on it, probably nobody tried.
U-boot uses it's own decompressor, so it's completely independent of
zboot framework (piggy.o building, in-kernel algos). That's why I'm
reluctant to merge vmlinuz and uImage build stages: these do
completely different things. U-boot may support compression algos not
included in the kernel and vice versa. Or some evil perverted person
might want to build (un)compressed u-boot image from vmlinuz kernel,
and it will probably work. ;)

Should I create SYS_SUPPORTS_UBOOT then?
Like this:

arch/mips/Kconfig:

+config SYS_SUPPORTS_UBOOT
+        bool
+        select HAVE_KERNEL_GZIP
+        select HAVE_KERNEL_BZIP2
+        select HAVE_KERNEL_LZMA
+        select HAVE_KERNEL_LZO

arch/mips/Makefile:

+all-$(CONFIG_SYS_SUPPORTS_UBOOT)+= uImage

...

+# u-boot
+uImage: vmlinux.bin FORCE
+       $(Q)$(MAKE) $(build)=arch/mips/boot/u-boot \
+         VMLINUX=$(vmlinux-32) VMLINUXBIN=arch/mips/boot/vmlinux.bin \
+         VMLINUX_LOAD_ADDRESS=$(load-y) arch/mips/boot/u-boot/$@

Of course install and clean targets will be added as well.
This will prevent vmlinuz from building and build uImage with chosen
compression algo instead.

I intend to keep u-boot/Makefile separate still. Of course it creates
some code duplication, but I believe proper functional decoupling is
more important in this case.
u-boot/Makefile is (almost) architecture independent and can be easily
adopted by other arch if such need arises.

Comments and suggestions welcome.

Regards,
Sergey