Writing C programs for Xbox 360 possible! :)

[sectroyer]

Hi would like to announce that It is now possible to write standard C apps for Xbox 360.

Here is the example app:
http://sectroyer.110mb.com/xbox/hello.c
It uses library xbox360.c that is also here:
http://sectroyer.110mb.com/xbox/xbox360.c
And compiled version:
http://sectroyer.110mb.com/xbox/hello.bin

The code should be compiled by with the following commands:
powerpc64-linux-gnu-gcc hello.c -nostdlib -Ttext=0x1300000 
powerpc64-linux-gnu-objcopy -O binary a.out hello.bin
echo "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" >> ./hello.bin

I am now working to add support for basic libc functions printf/mem* and all that stuff. If I can xbox360.c will include standard powerpc65 linux (by using #include <foo.h>) but sometimes it is required to use a specific library for Xbox 360 in that case it is included in a different way (by using #include "bar.c") and then bar.c has to be also downloaded from the site (i.e. http://sectroyer.110mb.com/xbox/bar.c).

I would like to thank mwk from asm channel for help with toc section initialization. Felix Domke from free60 project for allowing me to use a piece of his Linux loader code. And stonesmurf from XBH for doing tons of test on his box and having so much patience for my lack of knowledge

I hope this will help people to develop their own small apps for Xbox 360.
Please note that there is one problem: getchar function sometimes returns an enter key (0xa) where in fact it was not pressed. It can cause gets function to return without getting anything from the user. Sample code can also behave in this way. You will just have to correct the code by adding some getchar(); lines.

[tmbinc]

Also, i've now put up XeLL into the free60 cvs (http://free60.cvs.sourceforge.net/free60/xell/). It includes basic hardware support for DVDROM, Network and provides a simple C environment.

Feel free ripping any code, but it's all GPLv2.

Also, with this loader, you can load linux (using the posted patches, they should be complete).

[Cpasjuste]

Omg, thanks tmbinc its an awsome news for me.

Edit : I just linked this thread to xbox-scene forum since its a really cool news for me, let me know if i did a mistake.

[k0mpresd]

yes, thank you

[Cpasjuste]

Thanks for your work again tmbinc.
I have a little question anyway, could you make a default configuration file for the xenon kernel build process so we can do : "make xenon_defconfig" to create the default configfile like its usally the case ? (eg for ps3).

[warpjavier]

Hi everyone,
Glad to see this released, I can't wait to see linux running in my 360. 

Trying to compile xell, but got some errors:

powerpc-elf-gcc -Iinclude -m64 -c -o startup2.o startup2.S
startup2.S:0: error: -m64 not supported in this configuration
make: *** [startup2.o] Error 1

Then I changed -m64 to -mpowerpc64 and everything compiles but does not link and I got this error:

powerpc-elf-gcc -n -T rom.lds -nostdlib -o rom.elf  startup2.o main.o string.o
sprintf.o ctype.o time.o cache.o  ./lwip/core/tcp_in.o ./lwip/core/inet.o ./lwi
/core/mem.o ./lwip/core/memp.o ./lwip/core/netif.o ./lwip/core/pbuf.o ./lwip/co
e/stats.o ./lwip/core/sys.o ./lwip/core/tcp.o  ./lwip/core/ipv4/ip_addr.o ./lwi
/core/ipv4/icmp.o ./lwip/core/ipv4/ip.o ./lwip/core/ipv4/ip_frag.o ./lwip/core/
cp_out.o ./lwip/core/udp.o ./lwip/netif/etharp.o ./lwip/netif/loopif.o ./lwip/c
re/dhcp.o ./lwip/core/raw.o ./lwip/arch/xenon/lib.o  ./lwip/arch/xenon/netif/en
t.o  network.o tftp.o httpd/httpd.o httpd/vfs.o dtc.o cdrom.o
/usr/local/lib/gcc/powerpc-elf/4.1.1/../../../../powerpc-elf/bin/ld: section .t
xt [00000000 -> 0000f97b] overlaps section .bss [00000000 -> 000d6e1b]
collect2: ld returned 1 exit status
make: *** [rom.elf] Error 1

I'm not sure that changing -m64 to -mpowerpc64 would work. But anyway I couldn't manage to get rid of this error.

Help will be appreciated

warpjavier

PS. Keep up the good work guys!

[tmbinc]

I've uploaded my .config file at http://rapidshare.com/files/21917268/.config.html , that should be fine for a start.

warpjavier, i think your crosscompiler is not ok. Please compiler a crosscompiler for powerpc64-linux (as oppose to powerpc-linux). But i'm not sure about the concrete differences.

[kalle_19]

tmbinc: What Distro do you use? Hasn't suse enterprise a powerpc64-linux-gcc binary?

[tmbinc]

i've manually compiled my toolchain using crosstool (gcc-4.1.0-glibc-2.3.6, modified to powerpc64-linux).

[Cpasjuste]

I'm sorry tmbinc but i have another question :

First thanks again for taking the time to send your config file, but i have the same problem. I'm not a linux guru, but i presume that i should copy a rootfs on my hardrive isnt it (i dont have the hardware to) ? here is my prob :

Code:

[   84.656515] VFS: Cannot open root device "sda1" or unknown-block(8,1)
[   84.672804] Please append a correct "root=" boot option
[   84.687883] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(8,1)
[   84.706218]  <0>Rebooting in 180 seconds..

My boot process log :
http://mydedibox.homelinux.com/downloads/x360/xlinux.txt

[tmbinc]

Nice that it works for you. btw, people using samsung drives have to disable that sata channel, or fix the kernel. XeLL enables modeB for hitachi, but that of course doesn't help for samsung. might be an easy fix, i don't know.

Yes, you need a root file system available.

Be careful when overwriting your harddisk. better use a different one. If you overwrite the signature block on your retail harddisk, it will never work again for the original kernel. (it will be fine for linux, though).

Somebody should make a live cd.

[Cpasjuste]

Yep i think i really understand now,  our problem is that our hard disk partition (fatx like xbox1 ?) isnt properly recognized :

Code:

[   81.153746] SCSI device sda: 39070080 512-byte hdwr sectors (20004 MB)
[   81.170933] sda: Write Protect is off
[   81.185406] SCSI device sda: write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[   81.205826]  sda: unknown partition table

The solution would be to either format my hardrive to a standard linux partition, make a compatible fatx? driver to load a virtual rootfs, or to boot on usb.
I'll try right now to boot on an usb hard drive since its properly recognized on the startup process

[Surrido]

If I remember right TheSpecialist's HD tool allows to use also larger than 20GB HD to work as 360 HDs. However the rest of the space could not be used since the signature only allows 20GB.

maybe it is possible to have 2 partitions. one 20GB signed my M$ and one with linux file system...

[tmbinc]

You can use bigger HDDs today. They just won't work in dashboard etc., but will work under linux.

[Surrido]

the question is, are you able to use a HD split into 20GB M$ and rest linux...

[tmbinc]

Yes, there was a (now deleted) post inbetween, to which i've answered.

(Somehow i start to dislike that posts are removed without notice - even if they are OT or whatever). But IANAM, so I don't *really* care.

You could try setting a "host protected area". That should reduce the net capacity of the drive, so the drive is reported as a smaller drive. Linux already knows how to disable the HPA.

TheSpecialist, do you think this would be possible?

[TheSpecialist]

Yes, there was a (now deleted) post inbetween, to which i've answered.

(Somehow i start to dislike that posts are removed without notice - even if they are OT or whatever). But IANAM, so I don't *really* care.

You could try setting a "host protected area". That should reduce the net capacity of the drive, so the drive is reported as a smaller drive. Linux already knows how to disable the HPA.

TheSpecialist, do you think this would be possible?

Hi tmbinc, some great work you've done, congratulations
Anyway, yeah, if the drive reports different size in the 'identify_device' packet, then yes, it's possible. But I don't know about HPA on the WD drives, haven't looked at it ...

[Cpasjuste]

Hehe ^^

Code:

cpasjuste@xenon$ cat /proc/cpuinfo
processor : 0
cpu : Xenon, altivec supported
clock : 3192.000000MHz
revision : 2.0 (pvr 0071 0200)

processor : 2
cpu : Xenon, altivec supported
clock : 3192.000000MHz
revision : 2.0 (pvr 0071 0200)

processor : 4
cpu : Xenon, altivec supported
clock : 3192.000000MHz
revision : 2.0 (pvr 0071 0200)

timebase : 49875000
platform : Xenon
machine : CHRP Xenon Game Console

[Cpasjuste]

I have now some problem's to make X to work but i will work on it. Its just so nice already.
Anyway, it seems that the external usb hardrive isnt mounted when the kernel is booting, it is recognized its sure but it is only mounted after my nfs-root is loaded. Is theire a way to mount an usb drive directly from a kernel command line ? For now i'm using nfs to make the root filesystem but its not a final solution ..

[tmbinc]

X requires a special driver which takes care of the tiling. I have it here but i'm not the only author of it so i need to fix up some stuff before.

Interesting is, btw, that there are two different CPUs: On one of my (retail) xboxes, the PVR is 00710300, all the others have 00710200. I couldn't find any differences, though.

you can boot from usb, you probably need a root fs mount delay to make sure it will scan the usb devices first. and of course you need usb-storage etc. all in kernel.

You could also write an initramfs, which is probably the right way to do this :)