Makefile: Introduced super-simple config file

Factor out all configuration details into a separate configuration file
names config.mk. This file is added to .gitignore, but a default config
file is supplied in config-default.mk.

The default config file creates kernel command boot lines for NFS boots
based on a script obtaining the host IP addres. Naturally users can
change this to a static IP or another script if they wish.

The config file lets users select a system and other config options
depend on this overall setting.

I am no expert on Makefiles, so there could be better ways to accomplish
these things, but I think this suffices for now.

This patch applies after Peter Maydell's latest patch series, which in turn
applies to the following tree:
git://linux-arm.org/boot-wrapper.git kvm-smp

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
---
 .gitignore        |    1 +
 Makefile          |   39 ++++--------------------
 boot.S            |   26 +---------------
 config-default.mk |   86 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 get_ip.sh         |    7 ++++
 5 files changed, 103 insertions(+), 56 deletions(-)
 create mode 100644 config-default.mk
 create mode 100755 get_ip.sh

On 9 December 2011 05:27, Christoffer Dall
<c.dall@virtualopensystems.com> wrote:
>  %: force
> +       $(warning ehehehehh $@)
>        $(MAKE) -C $(KERNEL_SRC) $@

Stray debug tracing?

> diff --git a/boot.S b/boot.S
> index e1c8d78..d1c766d 100644
> --- a/boot.S
> +++ b/boot.S
> @@ -142,30 +142,8 @@ atags:
>        @ ATAG_CMDLINE
>        .long   (1f - .) >> 2
>        .long   0x54410009
> -#ifdef KCMD
> -        /* User-specified command line always overrides */
> -        .asciz KCMD
> -#else
> -#ifdef MACH_MPS
> -       .asciz  "rdinit=/bin/sh console=ttyAMA3 mem=4M earlyprintk"
> -#elif defined(VEXPRESS)
> -
> -#ifdef USE_INITRD
> -       .asciz  "console=ttyAMA0 mem=512M mem=512M@0x880000000 earlyprintk ip=192.168.27.200::192.168.27.1:255.255.255.0:angstrom:eth0:off"
> -#else /* VEXPRESS && !USE_INITRD */
> -       .asciz  "console=ttyAMA0 mem=512M mem=512M@0x880000000 earlyprintk root=/dev/nfs nfsroot=192.168.27.93:/srv/nfs_root,tcp rw ip=dhcp nfsrootdebug"
> -#endif
> -
> -#else /* ! VEXPRESS && ! MACH_MPS */
> -
> -#ifdef USE_INITRD
> -       .asciz  "console=ttyAMA0 mem=256M earlyprintk"
> -#else
> -       .asciz  "root=/dev/nfs nfsroot=10.1.77.43:/work/debootstrap/arm ip=dhcp console=ttyAMA0 mem=256M earlyprintk"
> -#endif
> -
> -#endif
> -#endif
> +        /* Use the C-define for the kernel boot command */
> +       .ascii  KCMD
>        .align  2
>  1:

This is an unrelated change, really.
> +USE_INITRD ?= no
> +ifeq ($(USE_INITRD),yes)
> +CPPFLAGS       += -DUSE_INITRD
> +FILESYSTEM     = filesystem.cpio.gz

This should be a "?=", so you can set USE_INITRD and also override
FILESYSTEM.

> +# Default NFS root
> +NFS_ROOT       ?= /srv/nfsroot
> +NFS_SERVER     ?= $(shell ./get_ip.sh)

> --- /dev/null
> +++ b/get_ip.sh
> @@ -0,0 +1,7 @@
> +#/bin/bash
> +
> +ifconfig | \
> +       grep 'inet addr:'| \
> +       grep -v '127.0.0.1' | \
> +       cut -d: -f2 | \
> +       awk '{ print $1}'

This doesn't work on systems with more than one non-loopback
network interface (it prints the IP addresses for all of them).

How about this instead?

# there's no shorthand := equivalent of ?= and we don't want
# to run the shell every time we use the variable
ifeq ($(origin NFS_SERVER), undefined)
NFS_SERVER := $(shell ip addr show scope global | sed -ne '/inet/{s/
*inet \([^/]*\)\/.*/\1/p;q}')
endif

(also saves having to have an external script)

-- PMM

On Fri, Dec 9, 2011 at 6:08 AM, Peter Maydell <peter.maydell@linaro.org> wrote:
> On 9 December 2011 05:27, Christoffer Dall
> <c.dall@virtualopensystems.com> wrote:
>>  %: force
>> +       $(warning ehehehehh $@)
>>        $(MAKE) -C $(KERNEL_SRC) $@
>
> Stray debug tracing?

oh yeah :)

>
>> diff --git a/boot.S b/boot.S
>> index e1c8d78..d1c766d 100644
>> --- a/boot.S
>> +++ b/boot.S
>> @@ -142,30 +142,8 @@ atags:
>>        @ ATAG_CMDLINE
>>        .long   (1f - .) >> 2
>>        .long   0x54410009
>> -#ifdef KCMD
>> -        /* User-specified command line always overrides */
>> -        .asciz KCMD
>> -#else
>> -#ifdef MACH_MPS
>> -       .asciz  "rdinit=/bin/sh console=ttyAMA3 mem=4M earlyprintk"
>> -#elif defined(VEXPRESS)
>> -
>> -#ifdef USE_INITRD
>> -       .asciz  "console=ttyAMA0 mem=512M mem=512M@0x880000000 earlyprintk ip=192.168.27.200::192.168.27.1:255.255.255.0:angstrom:eth0:off"
>> -#else /* VEXPRESS && !USE_INITRD */
>> -       .asciz  "console=ttyAMA0 mem=512M mem=512M@0x880000000 earlyprintk root=/dev/nfs nfsroot=192.168.27.93:/srv/nfs_root,tcp rw ip=dhcp nfsrootdebug"
>> -#endif
>> -
>> -#else /* ! VEXPRESS && ! MACH_MPS */
>> -
>> -#ifdef USE_INITRD
>> -       .asciz  "console=ttyAMA0 mem=256M earlyprintk"
>> -#else
>> -       .asciz  "root=/dev/nfs nfsroot=10.1.77.43:/work/debootstrap/arm ip=dhcp console=ttyAMA0 mem=256M earlyprintk"
>> -#endif
>> -
>> -#endif
>> -#endif
>> +        /* Use the C-define for the kernel boot command */
>> +       .ascii  KCMD
>>        .align  2
>>  1:
>
> This is an unrelated change, really.

Why do you think so? The fact that all the config settings depending
on the board type is now set in the config file eliminates the need to
have this check in the boot.S file. I can split it into two patches if
you want, but....

should be .asciz though I guess.


>> +USE_INITRD ?= no
>> +ifeq ($(USE_INITRD),yes)
>> +CPPFLAGS       += -DUSE_INITRD
>> +FILESYSTEM     = filesystem.cpio.gz
>
> This should be a "?=", so you can set USE_INITRD and also override
> FILESYSTEM.
>
yes, you're right, I missed that one.

>> +# Default NFS root
>> +NFS_ROOT       ?= /srv/nfsroot
>> +NFS_SERVER     ?= $(shell ./get_ip.sh)
>
>> --- /dev/null
>> +++ b/get_ip.sh
>> @@ -0,0 +1,7 @@
>> +#/bin/bash
>> +
>> +ifconfig | \
>> +       grep 'inet addr:'| \
>> +       grep -v '127.0.0.1' | \
>> +       cut -d: -f2 | \
>> +       awk '{ print $1}'
>
> This doesn't work on systems with more than one non-loopback
> network interface (it prints the IP addresses for all of them).
>
> How about this instead?
>
> # there's no shorthand := equivalent of ?= and we don't want
> # to run the shell every time we use the variable
> ifeq ($(origin NFS_SERVER), undefined)
> NFS_SERVER := $(shell ip addr show scope global | sed -ne '/inet/{s/
> *inet \([^/]*\)\/.*/\1/p;q}')
> endif
>
> (also saves having to have an external script)
>
ok, looks good.