[LinuxBIOS] buildrom configurations for serengeti-cheetah 64-bit

[Myles Watson]

I know this patch is pretty rough.  It's just meant as an example of what
I'd like to be able to do with buildrom.  It is a patch which enables most
of buildrom to succeed building for 64-bit.

When I use Linux-As-Bootloader, I want to use a 64-bit kernel so that any
patches I have to do for my hardware only need to be done for one
architecture.

A while ago I did a wiki page
http://linuxbios.org/index.php/Tyan_S2892_Build_Tutorial outlining how to
use buildrom to put the 64-bit kernel in the ROM.

I wanted to fit it into the new buildrom architecture, but I ran into a few
problems:

1.	There's not a clear way to add architectures for targets (Especially
since it really only makes sense for 64-bit)

a.	I think that the same configuration variable should be used for the
target architecture for the kernel and uClibc
b.	We could add a suffix to every default configuration file (e.g.,
defconfig-serengeti_cheetah-i386 or defconfig-serengeti_cheetah-x86_64

2.	It would be nice to be able to set the ROM size if you have a larger
one than comes standard with the platform

I think that buildrom is the way to go and I like the make menuconfig.

In order to make the 64-bit kernel fit as I configured it, I excluded kexec
from the ROM and included a statically-linked kexec on the boot drive, so it
was nice to be able to remove the kexec tools from the image.

As soon as we decide the best way, I'll clean it up and add
serengeti_cheetah-x86_64 support and tyan_s2892-x86_64 support.

Thanks,

Myles

[Jordan Crouse]

On 26/10/07 13:58 -0600, Myles Watson wrote:
> When I use Linux-As-Bootloader, I want to use a 64-bit kernel so that any
> patches I have to do for my hardware only need to be done for one
> architecture.

This looks pretty good.  I'm not really sure if I understand why you would
need a 64 bit kernel for a LAB, but I'm all for making it possible.
> There's not a clear way to add architectures for targets (Especially
>
> since it really only makes sense for 64-bit)

There configuration options in the platform configs that related to this,
but only on a very high end level.  It wouldn't be too difficult to do what
you are suggesting, though.
> a.	I think that the same configuration variable should be used for the
> target architecture for the kernel and uClibc

Agreed - you *could* do 64 bit kernel / 32 bit uclibc, but why?
> b.	We could add a suffix to every default configuration file (e.g.,
> defconfig-serengeti_cheetah-i386 or defconfig-serengeti_cheetah-x86_64

Thats fine - I don't have any problem with that.
> It would be nice to be able to set the ROM size if you have a larger
>
> one than comes standard with the platform

This is hard to do in v2, and I'm not sure how we could get around it,
because it would involve in-place SED fu and other such things that I'm
not 100% sure we want to be doing (and supporting).  This would be easier
for v3, and if its not easier for v3, now is the time to make it easier.

Comments below:
> diff -urN buildrom-devel.org/packages/kernel/kernel.inc buildrom-devel/packages/kernel/kernel.inc
> --- buildrom-devel.org/packages/kernel/kernel.inc	2007-10-25 16:06:51.000000000 -0600
> +++ buildrom-devel/packages/kernel/kernel.inc	2007-10-25 16:50:04.000000000 -0600
> @@ -41,25 +41,26 @@
>    @ touch $@
> $(KERNEL_SRC_DIR)/.config: $(KERNEL_STAMP_DIR)/.patched
> @ echo $(KERNEL_CONFIG)
> @ cat $(KERNEL_CONFIG) | sed -e s:^CONFIG_LOCALVERSION=.*:CONFIG_LOCALVERSION="$(ROM_VERSION)": > $(KERNEL_SRC_DIR)/.config

What are we echoing here?
> -$(KERNEL_SRC_DIR)/arch/i386/boot/bzImage: $(KERNEL_SRC_DIR)/.config
> +$(KERNEL_SRC_DIR)/arch/$(UCLIBC_ARCH)/boot/bzImage: $(KERNEL_SRC_DIR)/.config

Throughout, I'll vote for LAB_ARCH or TARGET_ARCH over UCLIBC_ARCH.
> @ echo "Building kernel..."
> @ $(MAKE) -C $(KERNEL_SRC_DIR) ARCH=i386 \
> @ $(MAKE) -C $(KERNEL_SRC_DIR) ARCH=$(UCLIBC_ARCH) \
> KERNEL_CC="$(CC)" KERNEL_LD="$(LD)" > $(KERNEL_BUILD_LOG) 2>&1
> -$(OUTPUT_DIR)/bzImage: $(KERNEL_SRC_DIR)/arch/i386/boot/bzImage
> +$(OUTPUT_DIR)/bzImage: $(KERNEL_SRC_DIR)/arch/$(UCLIBC_ARCH)/boot/bzImage
>    @ install -d $(OUTPUT_DIR)
>    @ install -m 0644 $< $@
> -$(OUTPUT_DIR)/vmlinux: $(KERNEL_SRC_DIR)/arch/i386/boot/bzImage
> +$(OUTPUT_DIR)/vmlinux: $(KERNEL_SRC_DIR)/arch/$(UCLIBC_ARCH)/boot/bzImage
>    @ install -d $(OUTPUT_DIR)
>    @ install -m 0644 $(KERNEL_SRC_DIR)/vmlinux $@
> $(KERNEL_STAMP_DIR)/.headers: $(KERNEL_SRC_DIR)/.config $(STAGING_DIR)/host/bin/unifdef
>    @ echo "Installing kernel headers..."
>    @( export PATH=$(PATH):$(STAGING_DIR)/host/bin; \
> $(MAKE) -C $(KERNEL_SRC_DIR) ARCH=i386 \
> $(MAKE) -C $(KERNEL_SRC_DIR) ARCH=$(UCLIBC_ARCH) \
> INSTALL_HDR_PATH=$(STAGING_DIR)/ headers_install > $(KERNEL_INSTALL_LOG) 2>&1)
> @ touch $@
> diff -urN buildrom-devel.org/packages/kernel/serengeti_cheetah-kernel.mk buildrom-devel/packages/kernel/serengeti_cheetah-kernel.mk
> --- buildrom-devel.org/packages/kernel/serengeti_cheetah-kernel.mk	2007-10-24 12:05:13.000000000 -0600
> +++ buildrom-devel/packages/kernel/serengeti_cheetah-kernel.mk	2007-10-25 16:59:06.000000000 -0600
> @@ -2,10 +2,10 @@
> KERNEL_URL=http://kernel.org/pub/linux/kernel/v2.6/
> KERNEL_SOURCE=linux-$(KERNEL_VERSION).tar.bz2
> -KERNEL_CONFIG=$(PACKAGE_DIR)/kernel/conf/defconfig-serengeti_cheetah
> +KERNEL_CONFIG=$(PACKAGE_DIR)/kernel/conf/defconfig-serengeti_cheetah-x86_64

This obviously would need to be addressed as discussed above.
> -#TINY_DIR=$(PACKAGE_DIR)/kernel/patches/tiny
> -#KERNEL_PATCHES += $(shell ls $(TINY_DIR)/*.patch)
> +TINY_DIR=$(PACKAGE_DIR)/kernel/patches/tiny-2.6.18.1
> +KERNEL_PATCHES += $(shell ls $(TINY_DIR)/*.patch)

This seems to be your local stuff - we would want to make sure that this
gets fixed right - tiny should match the kernel in question.
> $(SOURCE_DIR)/$(KERNEL_SOURCE):

<snip defconfig>

diff -urN buildrom-devel.org/packages/uclibc/uclibc.mk buildrom-devel/packages/uclibc/uclibc.mk
--- buildrom-devel.org/packages/uclibc/uclibc.mk	2007-10-24 15:16:38.000000000 -0600
+++ buildrom-devel/packages/uclibc/uclibc.mk	2007-10-26 08:48:56.000000000 -0600
@@ -26,13 +26,14 @@
    @ touch $@

$(UCLIBC_SRC_DIR)/.config: $(UCLIBC_STAMP_DIR)/.unpacked
> @ cp $(PACKAGE_DIR)/uclibc/conf/defconfig $(UCLIBC_SRC_DIR)/.config
> @ cp $(PACKAGE_DIR)/uclibc/conf/defconfig-$(UCLIBC_ARCH) $(UCLIBC_SRC_DIR)/.config
> $(UCLIBC_SRC_DIR)/lib/libc.a: $(UCLIBC_SRC_DIR)/.config
>    @ echo "Building uclibc..."
> @ echo $(UCLIBC_ARCH)
> @ ( unset CFLAGS; unset LDFLAGS; \
> $(MAKE) -C $(UCLIBC_SRC_DIR) TARGET_ARCH="$(UCLIBC_ARCH)" \
> CC="$(CC) $(CROSS_CFLAGS)" LD="$(LD) $(CROSS_LDFLAGS)" \
> CC="$(CC)" LD="$(LD)" \

Hmm - does uclibc do the right thing w.r.t flags now?  If now, we'll need an
ifdef to set teh right CC and LD flags.

Jordan