[LinuxBIOS] LinuxBIOS and FreeBSD

[Philip Schulz]

Hi,

I recently played around with LinuxBIOS and FreeBSD. In short, it 
somewhat works in QEMU using ADLO, see [1]. While trying to build 
LinuxBIOS and ADLO on FreeBSD, I came across some problems. They all 
come from the assumption that "make" is "GNU make" which isn't true on 
the BSDs. I've uploaded some really hackish patches to [2]. 
Unfortunately, I have no idea how to detect FreeBSD from a Makefile or a 
Python script. But maybe someone on this list knows and wants enhance 
the patches so they can be included in the LinuxBIOS tree.

Regards,

Philip

[1] http://linuxbios.org/index.php/Booting_FreeBSD_using_LinuxBIOS
[2] http://linuxbios.org/images/b/b6/LinuxBIOS_ADLO_FreeBSD.tgz

[Uwe Hermann]

On Thu, Oct 25, 2007 at 04:44:28PM +0200, Philip Schulz wrote:
> I recently played around with LinuxBIOS and FreeBSD. In short, it 
> somewhat works in QEMU using ADLO, see [1]. While trying to build

Great to hear, thanks!
> LinuxBIOS and ADLO on FreeBSD, I came across some problems. They all 
> come from the assumption that "make" is "GNU make" which isn't true on 
> the BSDs. I've uploaded some really hackish patches to [2].

Please post all patches to the list, with a Signed-off-by:
http://linuxbios.org/index.php/Development_Guidelines#Sign-off_Procedure

Much easier to review that way, and we don't commit any patches which
are lacking a proper Signed-off-by line.
> Unfortunately, I have no idea how to detect FreeBSD from a Makefile or a 
> Python script. But maybe someone on this list knows and wants enhance 
> the patches so they can be included in the LinuxBIOS tree.

There are some good hints in the Debian GNU/kFreeBSD porting website:
http://glibc-bsd.alioth.debian.org/porting/PORTING

Partly Debian/kFreeBSD specific, but most of it should also be true for
plain FreeBSD.

Most of your patch is just make -> gmake, so it should be easy to use
$(MAKE) everywhere and set that to "gmake" on FreeBSD and "make"
everywhere else.
> [1] http://linuxbios.org/index.php/Booting_FreeBSD_using_LinuxBIOS

Nice, thanks for adding that page!

Can you please attach a license to that wiki page? Either GPL, or
Creative Commons, or public domain, anything free-ish will do.
There are wiki templates you can use, e.g. {{GPL}}, {{PD-self}} etc.

Thanks, Uwe.

[Peter Stuge]

On Thu, Oct 25, 2007 at 04:44:28PM +0200, Philip Schulz wrote:
> I recently played around with LinuxBIOS and FreeBSD. In short, it
> somewhat works in QEMU using ADLO

Cool!

Do you know the FBSD boot process internals well?

I discussed this at Linuxforum.dk this spring with some FBSD people
and have a contact I can dig up if you want to pick up the ball.

The idea is to short-circuit all the BIOS junk that ADLO emulates and
have LB/elfboot/FILO start the kernel directly, as is done with
Linux.

Since the *BSD boot process is split into several steps that may not
be quite as easy as with Linux however.

//Peter

[Philip Schulz]

Am 25.10.2007 18:54, Uwe Hermann schrieb:
[...]
> Please post all patches to the list, with a Signed-off-by:
> http://linuxbios.org/index.php/Development_Guidelines#Sign-off_Procedure
>
> Much easier to review that way, and we don't commit any patches which
> are lacking a proper Signed-off-by line.

Thanks for the pointer.
> > Unfortunately, I have no idea how to detect FreeBSD from a Makefile or a 
> > Python script. But maybe someone on this list knows and wants enhance 
> > the patches so they can be included in the LinuxBIOS tree.
>
> There are some good hints in the Debian GNU/kFreeBSD porting website:
> http://glibc-bsd.alioth.debian.org/porting/PORTING
>
> Partly Debian/kFreeBSD specific, but most of it should also be true for
> plain FreeBSD.
>
> Most of your patch is just make -> gmake, so it should be easy to use
> $(MAKE) everywhere and set that to "gmake" on FreeBSD and "make"
> everywhere else.

Ok, thanks for the hints. I'll see what I can come up with.
> > [1] http://linuxbios.org/index.php/Booting_FreeBSD_using_LinuxBIOS
>
> Nice, thanks for adding that page!
>
> Can you please attach a license to that wiki page? Either GPL, or
> Creative Commons, or public domain, anything free-ish will do.
> There are wiki templates you can use, e.g. {{GPL}}, {{PD-self}} etc.

Done.

[Philip Schulz]

Am 26.10.2007 02:07, Peter Stuge schrieb:
> On Thu, Oct 25, 2007 at 04:44:28PM +0200, Philip Schulz wrote:
> > I recently played around with LinuxBIOS and FreeBSD. In short, it
> > somewhat works in QEMU using ADLO
>
> Cool!
>
> Do you know the FBSD boot process internals well?

No, I'm still learning.
> I discussed this at Linuxforum.dk this spring with some FBSD people
> and have a contact I can dig up if you want to pick up the ball.

I'm afraid I've just started so I might not even be qualified to ask 
good questions. But thanks for the offer anyways, I might get back to 
you once I've made some progress.
> The idea is to short-circuit all the BIOS junk that ADLO emulates and
> have LB/elfboot/FILO start the kernel directly, as is done with
> Linux.
>
> Since the *BSD boot process is split into several steps that may not
> be quite as easy as with Linux however.

Yes, the FreeBSD/i386 boot process is split into several steps. FWIW, 
there's a man page describing the boot process at [1].
  While you could probably use the FreeBSD kernel as a payload to 
LinuxBIOS, I don't think it would be a good idea. First, the FreeBSD 
GENERIC kernel, i.e. default kernel, is about 8.6 MBytes. The size could 
be reduced by removing drivers and options, but then it'd still be a few 
MBytes in size. Maybe gzipping the kernel image would work, I don't 
know. But there's a second and more important reason not to boot the 
kernel directly: The FreeBSD kernel doesn't understand command line 
options like "--init=/bin/sh" which I think the Linux kernel does. 
Instead, the FreeBSD kernel relies on a little program called "loader" 
to supply it with boot time options, e.g. selecting the default console 
or telling the kernel to boot in single-user mode. Also, the loader 
takes care of loading kernel modules at boot time. The loader will look 
for options in a file called /boot/loader.conf, parse it and then load 
the kernel from /boot/kernel/kernel. Obviously, the loader has to 
understand a fair amount of UFS in order to do that.
  So in short, I think the loader should be used as a LinuxBIOS payload 
instead of the kernel (which is what I'm going to try one of these 
days). I'm no expert though, so I might be wrong.

Regards,

Philip

[1]http://www.freebsd.org/cgi/man.cgi?query=boot&apropos=0&sektion=0&am...

[Uwe Hermann]

On Fri, Oct 26, 2007 at 08:14:35AM +0200, Philip Schulz wrote:
> > Can you please attach a license to that wiki page? Either GPL, or
> > Creative Commons, or public domain, anything free-ish will do.
> > There are wiki templates you can use, e.g. {{GPL}}, {{PD-self}} etc.
>
> Done.

Thanks!

Btw, you mention in the wiki that VGA won't work. AFAIK it _should_ work
with the latest LinuxBIOSv2 version and the required (patched)
vgabios-cirrus.bin file in your $HOME (or whereever your bios.bin is
stored). Also, I know for sure that VGA works in v3, too. While v3 is
still in development, the QEMU target works fine already (including VGA).

HTH, Uwe.

[Philip Schulz]

Uwe Hermann wrote:
> Btw, you mention in the wiki that VGA won't work. AFAIK it _should_  
> work
> with the latest LinuxBIOSv2 version and the required (patched)
> vgabios-cirrus.bin file in your $HOME (or whereever your bios.bin is
> stored). Also, I know for sure that VGA works in v3, too. While v3 is
> still in development, the QEMU target works fine already (including  
> VGA).

I didn't try VGA because I explicitly want a system w/o VGA. That's not
so important for QEMU, but I'd like to try things out on real hardware
sometime soon.

Anyways, I assume you're talking about the vgabios-cirrus.bin file build
from (patched) sources by the project at http://www.nongnu.org/vgabios/?
If so, I've just downloaded version 0.6a and tried to build it, but it
fails. The failure is documented below, if anyone is interested.

Regards,

Philip

vgabios-06a build failure follows:

[phs@thinkpad ~/vgabios-0.6a]$ gmake
gcc -o biossums biossums.c
biossums.c: In function 'main':
biossums.c:63: warning: incompatible implicit declaration of built-in
function 'memset'
gcc -o vbetables-gen vbetables-gen.c
./vbetables-gen > vbetables.h
gcc -E vgabios.c  -DVBE "-DVGABIOS_DATE="`date '+%d %b %Y'`"" >
_vgabios_.c
bcc -o vgabios.s -C-c -D__i86__ -S -0 _vgabios_.c
_vgabios_.c:1: error: Unknown preprocessor directive
_vgabios_.c:2: error: Unknown preprocessor directive
_vgabios_.c:3: error: Unknown preprocessor directive
_vgabios_.c:4: error: Unknown preprocessor directive
_vgabios_.c:5: error: Unknown preprocessor directive
_vgabios_.c:6: error: Unknown preprocessor directive

[...]

[phs@thinkpad ~/vgabios-0.6a]$ head _vgabios_.c
# 1 "vgabios.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "vgabios.c"
# 51 "vgabios.c"
# 1 "vgabios.h" 1

[Philip Schulz]

Hi,

On 10/25/07 18:54, Uwe Hermann wrote:
> On Thu, Oct 25, 2007 at 04:44:28PM +0200, Philip Schulz wrote:

[...]
> > Unfortunately, I have no idea how to detect FreeBSD from a Makefile or a 
> > Python script. But maybe someone on this list knows and wants enhance 
> > the patches so they can be included in the LinuxBIOS tree.

[...]
> Most of your patch is just make -> gmake, so it should be easy to use
> $(MAKE) everywhere and set that to "gmake" on FreeBSD and "make"
> everywhere else.

It seems that on FreeBSD, ${MAKE} is set to the name of the binary you 
invoke (gnumake is a hard-link to gmake in this example):

[phs@thinkpad ~]$ cat Makefile
all:
        echo ${MAKE}

[phs@thinkpad ~]$ make
echo make
make
[phs@thinkpad ~]$ gmake
echo gmake
gmake
[phs@thinkpad ~]$ gnumake
echo gnumake
gnumake

Anyways, attached is an updated version of the initial patch. It hopefully 
doesn't brake builds on Linux and makes LinuxBIOS (and ADLO) compile on 
FreeBSD. Also, this uses "domainname" instead of "dnsdomainname" on FreeBSD.

Signed-off-by: Philip Schulz

I hope this is the correct way to post a patch.

Regards,

Philip

Index: src/config/Config.lb
===================================================================
--- src/config/Config.lb	(revision 2944)
+++ src/config/Config.lb	(working copy)
@@ -5,7 +5,7 @@

makedefine CPP:= $(CC) -x assembler-with-cpp -DASSEMBLY -E
 makedefine LIBGCC_FILE_NAME := $(shell $(CC) -print-libgcc-file-name)
-makedefine GCC_INC_DIR := $(shell $(CC) -print-search-dirs | sed -ne "s/install: (.*)/\1include/gp")
+makedefine GCC_INC_DIR := $(shell if [ `uname` = "FreeBSD" ] ; then echo "/usr/include" ; else $(CC) -print-search-dirs | sed -ne "s/install: (.*)/\1include/gp" ; fi )

makedefine CPPFLAGS := -I$(TOP)/src/include -I$(TOP)/src/arch/$(ARCH)/include -I$(GCC_INC_DIR) $(CPUFLAGS)
 makedefine CFLAGS := $(CPU_OPT) $(CPPFLAGS) -Os -nostdinc -nostdlib -fno-builtin  -Wall
Index: src/config/Options.lb
===================================================================
--- src/config/Options.lb	(revision 2944)
+++ src/config/Options.lb	(working copy)
@@ -134,7 +134,7 @@
 end

define LINUXBIOS_COMPILE_DOMAIN
-	default "$(shell dnsdomainname)"
+	default "$(shell if [ `uname` = "FreeBSD" ] ; then domainname ; else dnsdomainname ; fi )"
    export always
    format ""%s""
    comment "Build domain name"
Index: util/ADLO/Makefile
===================================================================
--- util/ADLO/Makefile	(revision 2944)
+++ util/ADLO/Makefile	(working copy)
@@ -40,7 +40,7 @@
 #-------------------------------------------------

bios:
-	( cd ${BOCHS_B} ; make )
+	( cd ${BOCHS_B} ; ${MAKE} )
    sync

#-------------------------------------------------
@@ -101,7 +101,7 @@

clean:
    rm -rf *.o ${PAYLOAD}
-	(cd ${BOCHS_B} ; make clean ) 
+	(cd ${BOCHS_B} ; ${MAKE} clean )

distclean: clean
    rm -rf ${BOCHS_C}
Index: util/newconfig/config.g
===================================================================
--- util/newconfig/config.g	(revision 2944)
+++ util/newconfig/config.g	(working copy)
@@ -2158,7 +2158,7 @@
    for i, o in romimages.items():
    	file.write("%s/linuxbios.rom:\n" % o.getname())
    	file.write("\tif (cd %s; \\n" % o.getname())
-		file.write("\t\tmake linuxbios.rom)\\n")
+		file.write("\t\t${MAKE} linuxbios.rom)\\n")
    	file.write("\tthen true; else exit 1; fi;\n\n")
    file.write("clean: ")
    for i in romimages.keys():
@@ -2166,7 +2166,7 @@
    file.write("\n\n")
    for i, o in romimages.items():
    	file.write("%s-clean:\n" % o.getname())
-		file.write("\t(cd %s; make clean)\n\n" % o.getname())
+		file.write("\t(cd %s; ${MAKE} clean)\n\n" % o.getname())

for i in buildroms:
    	file.write("%s:" % i.name)