[Patch] i386: Xbox support

[Patch] i386: Xbox support

[Ed Schouten]

Added support for Microsoft Xbox gaming consoles by adding the config
option 'CONFIG_X86_XBOX'. This patch is very minimalistic and should give
the fellows at xbox-linux.org a starting point.
---

 CREDITS                            |    8 +++++++
 arch/i386/Kconfig                  |   16 ++++++++++++--
 arch/i386/Makefile                 |    3 ++
 arch/i386/boot/compressed/Makefile |    7 ++++++
 arch/i386/mach-xbox/Makefile       |    5 ++++
 arch/i386/mach-xbox/reboot.c       |   41
+++++++++++++++++++++++++++++++++++++
 arch/i386/pci/direct.c             |   15 +++++++++++++
 include/asm-i386/timex.h           |    2 +
 include/asm-i386/xbox.h            |   17 +++++++++++++++
 include/linux/pci_ids.h            |    1
 10 files changed, 113 insertions(+), 2 deletions(-)

diff -u -r --new-file linux-2.6.9-rc2/CREDITS linux-2.6.9-rc2-xbox/CREDITS
--- linux-2.6.9-rc2/CREDITS	2004-09-27 14:38:55.874666000 +0200
+++ linux-2.6.9-rc2-xbox/CREDITS	2004-09-27 19:34:06.201661000 +0200
@@ -2944,6 +2944,14 @@
 E:
 D: Macintosh IDE Driver

+N: Ed Schouten
+E: ed@il.fontys.nl
+W: http://g-rave.nl/
+D: Imported Xbox workarounds
+S: Klinkerstraat 20
+S: 5361 GW Grave
+S: The Netherlands
+
 N: Peter De Schrijver
 E: stud11@cc4.kuleuven.ac.be
 D: Mitsumi CD-ROM driver patches March version
diff -u -r --new-file linux-2.6.9-rc2/arch/i386/Kconfig
linux-2.6.9-rc2-xbox/arch/i386/Kconfig
--- linux-2.6.9-rc2/arch/i386/Kconfig	2004-09-27 14:38:58.438666000 +0200
+++ linux-2.6.9-rc2-xbox/arch/i386/Kconfig	2004-09-27 09:40:28.881666000
+0200
@@ -51,6 +51,18 @@

 	  If unsure, choose "PC-compatible" instead.

+config X86_XBOX
+	bool "Microsoft Xbox"
+	help
+	  This option is needed to make Linux boot on a Microsoft Xbox.
+
+	  If you are not planning on running this kernel on a Microsoft Xbox,
+	  say N here, otherwise the kernel you build will not be bootable.
+
+	  For more information about Xbox Linux, visit:
+
+	  http://www.xbox-linux.org/
+
 config X86_VOYAGER
 	bool "Voyager (NCR)"
 	help
@@ -1139,7 +1151,7 @@

 config MCA
 	bool "MCA support"
-	depends on !(X86_VISWS || X86_VOYAGER)
+	depends on !(X86_VISWS || X86_VOYAGER || X86_XBOX)
 	help
 	  MicroChannel Architecture is found in some IBM PS/2 machines and
 	  laptops.  It is a bus system similar to PCI or ISA. See
@@ -1202,7 +1214,7 @@

 config X86_BIOS_REBOOT
 	bool
-	depends on !(X86_VISWS || X86_VOYAGER)
+	depends on !(X86_VISWS || X86_VOYAGER || X86_XBOX)
 	default y

 config X86_TRAMPOLINE
diff -u -r --new-file linux-2.6.9-rc2/arch/i386/Makefile
linux-2.6.9-rc2-xbox/arch/i386/Makefile
--- linux-2.6.9-rc2/arch/i386/Makefile	2004-09-27 14:38:58.443666000 +0200
+++ linux-2.6.9-rc2-xbox/arch/i386/Makefile	2004-09-27 15:23:26.244666000
+0200
@@ -69,6 +69,9 @@
 mflags-$(CONFIG_X86_VOYAGER)	:= -Iinclude/asm-i386/mach-voyager
 mcore-$(CONFIG_X86_VOYAGER)	:= mach-voyager

+# Xbox subarch support
+core-$(CONFIG_X86_XBOX)		+= arch/i386/mach-xbox/
+
 # VISWS subarch support
 mflags-$(CONFIG_X86_VISWS)	:= -Iinclude/asm-i386/mach-visws
 mcore-$(CONFIG_X86_VISWS)	:= mach-visws
diff -u -r --new-file linux-2.6.9-rc2/arch/i386/boot/compressed/Makefile
linux-2.6.9-rc2-xbox/arch/i386/boot/compressed/Makefile
--- linux-2.6.9-rc2/arch/i386/boot/compressed/Makefile	2004-08-14
12:55:48.000000000 +0200
+++ linux-2.6.9-rc2-xbox/arch/i386/boot/compressed/Makefile	2004-09-27
09:40:28.917666000 +0200
@@ -7,6 +7,13 @@
 targets		:= vmlinux vmlinux.bin vmlinux.bin.gz head.o misc.o piggy.o
 EXTRA_AFLAGS	:= -traditional

+# Microsoft Xbox workaround:
+# Xbox v1.1+ crashes while decompressing the kernel when paging is off.
+# By disabling optimization we can fix this.
+ifeq ($(CONFIG_X86_XBOX),y)
+	CFLAGS_misc.o  := -O0
+endif
+
 LDFLAGS_vmlinux := -Ttext $(IMAGE_OFFSET) -e startup_32

 $(obj)/vmlinux: $(obj)/head.o $(obj)/misc.o $(obj)/piggy.o FORCE
diff -u -r --new-file linux-2.6.9-rc2/arch/i386/mach-xbox/Makefile
linux-2.6.9-rc2-xbox/arch/i386/mach-xbox/Makefile
--- linux-2.6.9-rc2/arch/i386/mach-xbox/Makefile	1970-01-01
01:00:00.000000000 +0100
+++ linux-2.6.9-rc2-xbox/arch/i386/mach-xbox/Makefile	2004-09-27
14:52:20.504666000 +0200
@@ -0,0 +1,5 @@
+#
+# Makefile for the linux kernel.
+#
+
+obj-$(CONFIG_X86_XBOX)		:= reboot.o
diff -u -r --new-file linux-2.6.9-rc2/arch/i386/mach-xbox/reboot.c
linux-2.6.9-rc2-xbox/arch/i386/mach-xbox/reboot.c
--- linux-2.6.9-rc2/arch/i386/mach-xbox/reboot.c	1970-01-01
01:00:00.000000000 +0100
+++ linux-2.6.9-rc2-xbox/arch/i386/mach-xbox/reboot.c	2004-09-27
19:30:30.836661000 +0200
@@ -0,0 +1,41 @@
+/*
+ * arch/i386/mach-xbox/reboot.c
+ * Ed Schouten <ed@il.fontys.nl>
+ *
+ * Originally done by:
+ * Olivier Fauchon <olivier.fauchon@free.fr>
+ * Anders Gustafsson <andersg@0x63.nu>
+ *
+ */
+
+#include <asm/io.h>
+#include <asm-i386/xbox.h>
+
+/* we don't use any of those, but dmi_scan.c needs 'em */
+void (*pm_power_off)(void);
+int reboot_thru_bios;
+
+static void xbox_pic_cmd(u8 command)
+{
+	outw_p(((XBOX_PIC_ADDRESS) << 1), XBOX_SMB_HOST_ADDRESS);
+	outb_p(SMC_CMD_POWER, XBOX_SMB_HOST_COMMAND);
+	outw_p(command, XBOX_SMB_HOST_DATA);
+	outw_p(inw(XBOX_SMB_IO_BASE), XBOX_SMB_IO_BASE);
+	outb_p(0x0a, XBOX_SMB_GLOBAL_ENABLE);
+}
+
+void machine_restart(char * __unused)
+{
+	printk(KERN_INFO "Sending POWER_CYCLE to XBOX-PIC.\n");
+	xbox_pic_cmd(SMC_SUBCMD_POWER_CYCLE);
+}
+
+void machine_power_off(void)
+{
+	printk(KERN_INFO "Sending POWER_OFF to XBOX-PIC.\n");
+	xbox_pic_cmd(SMC_SUBCMD_POWER_OFF);
+}
+
+void machine_halt(void)
+{
+}
diff -u -r --new-file linux-2.6.9-rc2/arch/i386/pci/direct.c
linux-2.6.9-rc2-xbox/arch/i386/pci/direct.c
--- linux-2.6.9-rc2/arch/i386/pci/direct.c	2004-08-14 12:54:51.000000000
+0200
+++ linux-2.6.9-rc2-xbox/arch/i386/pci/direct.c	2004-09-27
09:40:28.962666000 +0200
@@ -20,6 +20,21 @@
 	if (!value || (bus > 255) || (devfn > 255) || (reg > 255))
 		return -EINVAL;

+#ifdef CONFIG_X86_XBOX
+	/*
+	 * Workaround for the Microsoft Xbox:
+	 * Prevent it from tampering with some devices.
+	 */
+	if ((bus == 0) && !PCI_SLOT(devfn) && ((PCI_FUNC(devfn) == 1) ||
(PCI_FUNC(devfn) == 2)))
+		return -EINVAL;
+
+	if ((bus == 1) && (PCI_SLOT(devfn) || PCI_FUNC(devfn)))
+		return -EINVAL;
+
+	if (bus >= 2)
+		return -EINVAL;
+#endif
+
 	spin_lock_irqsave(&pci_config_lock, flags);

 	outl(PCI_CONF1_ADDRESS(bus, devfn, reg), 0xCF8);
diff -u -r --new-file linux-2.6.9-rc2/include/asm-i386/timex.h
linux-2.6.9-rc2-xbox/include/asm-i386/timex.h
--- linux-2.6.9-rc2/include/asm-i386/timex.h	2004-09-27 14:39:32.304666000
+0200
+++ linux-2.6.9-rc2-xbox/include/asm-i386/timex.h	2004-09-27
09:40:28.974666000 +0200
@@ -11,6 +11,8 @@

 #ifdef CONFIG_X86_ELAN
 #  define CLOCK_TICK_RATE 1189200 /* AMD Elan has different frequency! */
+#elif CONFIG_X86_XBOX
+#  define CLOCK_TICK_RATE 1125000 /* Microsoft Xbox */
 #else
 #  define CLOCK_TICK_RATE 1193182 /* Underlying HZ */
 #endif
diff -u -r --new-file linux-2.6.9-rc2/include/asm-i386/xbox.h
linux-2.6.9-rc2-xbox/include/asm-i386/xbox.h
--- linux-2.6.9-rc2/include/asm-i386/xbox.h	1970-01-01 01:00:00.000000000
+0100
+++ linux-2.6.9-rc2-xbox/include/asm-i386/xbox.h	2004-09-27
09:40:28.976666000 +0200
@@ -0,0 +1,17 @@
+/*
+ * include/asm-i386/xbox.h
+ * Ed Schouten <ed@il.fontys.nl>
+ */
+
+#define XBOX_SMB_IO_BASE               0xC000
+#define XBOX_SMB_HOST_ADDRESS          (0x4 + XBOX_SMB_IO_BASE)
+#define XBOX_SMB_HOST_COMMAND          (0x8 + XBOX_SMB_IO_BASE)
+#define XBOX_SMB_HOST_DATA             (0x6 + XBOX_SMB_IO_BASE)
+#define XBOX_SMB_GLOBAL_ENABLE         (0x2 + XBOX_SMB_IO_BASE)
+
+#define XBOX_PIC_ADDRESS               0x10
+
+#define SMC_CMD_POWER                  0x02
+#define SMC_SUBCMD_POWER_RESET         0x01
+#define SMC_SUBCMD_POWER_CYCLE         0x40
+#define SMC_SUBCMD_POWER_OFF           0x80
diff -u -r --new-file linux-2.6.9-rc2/include/linux/pci_ids.h
linux-2.6.9-rc2-xbox/include/linux/pci_ids.h
--- linux-2.6.9-rc2/include/linux/pci_ids.h	2004-09-27 14:39:37.453666000
+0200
+++ linux-2.6.9-rc2-xbox/include/linux/pci_ids.h	2004-09-27
09:40:28.981666000 +0200
@@ -1137,6 +1137,7 @@
 #define PCI_DEVICE_ID_NVIDIA_QUADRO4_900XGL	0x0258
 #define PCI_DEVICE_ID_NVIDIA_QUADRO4_750XGL	0x0259
 #define PCI_DEVICE_ID_NVIDIA_QUADRO4_700XGL	0x025B
+#define PCI_DEVICE_ID_NVIDIA_GEFORCE3_XBOX	0x02A0

 #define PCI_VENDOR_ID_IMS		0x10e0
 #define PCI_DEVICE_ID_IMS_8849		0x8849

Re: [Patch] i386: Xbox support

[Nick Piggin]

Ed Schouten wrote:
> Added support for Microsoft Xbox gaming consoles by adding the config
> option 'CONFIG_X86_XBOX'. This patch is very minimalistic and should give
> the fellows at xbox-linux.org a starting point.

Any real point to merging this? (I honestly don't know, I don't follow the
xbox hacking scene).

Re: [Patch] i386: Xbox support

[Will Dyson]

On Tue, 28 Sep 2004 10:03:39 +1000, Nick Piggin <nickpiggin@yahoo.com.au> wrote:
> Ed Schouten wrote:
> > Added support for Microsoft Xbox gaming consoles by adding the config
> > option 'CONFIG_X86_XBOX'. This patch is very minimalistic and should give
> > the fellows at xbox-linux.org a starting point.
> 
> Any real point to merging this? (I honestly don't know, I don't follow the
> xbox hacking scene).

As someone who owns a modchipped xbox (used mainly for media center
stuff), I would appreciate having fewer out of tree patches to apply
in order to run a new kernel. I can't vouch for any kind of critical
mass of users, however.

-- 
Will Dyson

Re: [Patch] i386: Xbox support

[Ed Schouten]

Hello Nick,

On Tue, 28 Sep 2004 10:03:39 +1000, Nick Piggin <nickpiggin@yahoo.com.au> wrote:
> Any real point to merging this? (I honestly don't know, I don't follow the
> xbox hacking scene).

Yes, it does (in my opinion). This small 7 KB patch allows you to run
a vanilla kernel on the machine (with exception of the video driver).

I also noticed my previous mailclient (Squirrelmail) did some
linebreaking. Please notice:

+ if ((bus == 0) && !PCI_SLOT(devfn) && ((PCI_FUNC(devfn) == 1) ||
(PCI_FUNC(devfn) == 2)))

should be one line ;-)

Yours sincerely,
-- 
 Ed Schouten <edschouten@gmail.com>
 Website: http://g-rave.nl/

Re: [Patch] i386: Xbox support

[Nick Piggin]

Ed Schouten wrote:
> Hello Nick,
> 
> On Tue, 28 Sep 2004 10:03:39 +1000, Nick Piggin <nickpiggin@yahoo.com.au> wrote:
> 
>>Any real point to merging this? (I honestly don't know, I don't follow the
>>xbox hacking scene).
> 
> 
> Yes, it does (in my opinion). This small 7 KB patch allows you to run
> a vanilla kernel on the machine (with exception of the video driver).
> 
> I also noticed my previous mailclient (Squirrelmail) did some
> linebreaking. Please notice:
> 
> + if ((bus == 0) && !PCI_SLOT(devfn) && ((PCI_FUNC(devfn) == 1) ||
> (PCI_FUNC(devfn) == 2)))
> 
> should be one line ;-)
> 
> Yours sincerely,

Well, I ask because there is probably quite a large number of embedded type
devices devices that you could "just add a small patch for" to get it working.

The added fact that you have to "hack" the hardware (I think?) to even get
it to run Linux makes it probably a bit more questionable (it is great that
we can run on xbox, but maybe not too harmful to keep it as an external patch).

Anyway I've otherwise got no objections ;) if you can convince Andrew and/or
Linus to merge it, then fine.

Re: [Patch] i386: Xbox support

[Ed Schouten]

On Tue, 28 Sep 2004 17:42:40 +1000, Nick Piggin <nickpiggin@yahoo.com.au> wrote:
> Well, I ask because there is probably quite a large number of embedded type
> devices devices that you could "just add a small patch for" to get it working.
> 
> The added fact that you have to "hack" the hardware (I think?) to even get
> it to run Linux makes it probably a bit more questionable (it is great that
> we can run on xbox, but maybe not too harmful to keep it as an external patch).

Yes, you have multiple options to get Linux on it (flash the BIOS with
cromwell, grub-based bootloader, alter some of its current software,
etc).

The reason why the Xbox-Linux folks and I think it should belong in
the main tree is adoption. Xbox Linux has been around since 2001 if I
remember correctly and there are almost no distributions around that
really support the Xbox. The people at Debian for example will only
add Xbox support if it is available in the main tree.

Yours,
-- 
 Ed Schouten <edschouten@gmail.com>
 Website: http://g-rave.nl/

Re: [Patch] i386: Xbox support

[Tonnerre]

[-- Attachment #1: Type: text/plain, Size: 331 bytes --]

Salut,

On Tue, Sep 28, 2004 at 10:46:56AM +0200, Ed Schouten wrote:
> Xbox Linux  has been around since  2001 if I  remember correctly and
> there  are almost no  distributions around  that really  support the
> Xbox.

Didn't Andy Green mention that there was Mandrake 9 for the X-Box, way
back in december 2002?

			    Tonnerre

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 189 bytes --]

Re: [Patch] i386: Xbox support

[Ed Schouten]

On Wed, 29 Sep 2004 20:21:43 +0200, Tonnerre <tonnerre@thundrix.ch> wrote:
> Didn't Andy Green mention that there was Mandrake 9 for the X-Box, way
> back in december 2002?

That was a 'hackjob' in cooperation with the Mandrake devvers, as far
as I know. But that doesn't make it any better, because that version
of Mandrake is outdated and it still uses the 2.4 kernel.

Yours,
-- 
 Ed Schouten <edschouten@gmail.com>
 Website: http://g-rave.nl/

Re: [Patch] i386: Xbox support

[Pavel Machek]

Hi!

> >>Any real point to merging this? (I honestly don't know, I don't follow the
> >>xbox hacking scene).
> >
> >
> >Yes, it does (in my opinion). This small 7 KB patch allows you to run
> >a vanilla kernel on the machine (with exception of the video driver).
> >
> >I also noticed my previous mailclient (Squirrelmail) did some
> >linebreaking. Please notice:
> >
> >+ if ((bus == 0) && !PCI_SLOT(devfn) && ((PCI_FUNC(devfn) == 1) ||
> >(PCI_FUNC(devfn) == 2)))
> >
> >should be one line ;-)
> >
> >Yours sincerely,
> 
> Well, I ask because there is probably quite a large number of embedded type
> devices devices that you could "just add a small patch for" to get it 
> working.

Yes, and we support most of them :-). This is not really different
from all the arm platforms etc.
									Pavel
-- 
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!

Re: [Patch] i386: Xbox support

[Nick Piggin]

Pavel Machek wrote:

>>Well, I ask because there is probably quite a large number of embedded type
>>devices devices that you could "just add a small patch for" to get it 
>>working.
> 
> 
> Yes, and we support most of them :-). This is not really different
> from all the arm platforms etc.


Yeah OK. I don't want to turn this into an argument, but the difference
is AFAIK, that many of them are made *for* running Linux (or at least as
a supported configuration). While the xbox requires you to circumvent
the hardware.

But on the other hand, "why not?" :)

As I said, so long as Linus or Andrew is happy with it, I don't care.

Switch back to Real mode and then boot strap

[Aboo Valappil]

Hi All,

I am new to this mailing list ... Need some help, PLEASE :)

I am running redhat Linux with kernel 2.4.21-4.EL.

Basically I have a requirement of re-booting ( Without really rebooting )
the OS from the hard disk ( even if a floppy is present or a bootable CD-ROM
is present).  Update CMOS to change the boot sequence is not an option for
my requirement.

My idea is to read the MBR off the hard disk and then jump to the memory
location of the MBR after switching to real mode. The thing I do not want to
do is to jump to real address FFFF:0000 because it is going to select the
boot device ( Where this selection, I do not have any control when I
rebooted )

I found a function in process.c ( arch/i386/kernel/ ) called
machine_real_restart(code,length) where you could give the address of a real
mode routine. If I call this function (ofcource from a kernel module) with
address pointed to a piece of code which has ljmp $0xffff,$0x0, the system
reboots fine. I WAS VERY EXCITED TO SEE THIS.

Proceeding to my next step, I generated an array of machine code (.code16),
where I use INT 13h to read the first sector off the hard drive to
0000:7c00, and then ljmp to 0000:7c000. I used the above kernel function to
call this. I am was so disappointed to see the SYSTEM JUST HANGS :( .

Here is the routine I am using ...

.code16
xorw %ax,%ax
movw %ax,%ds
movw %ax,%ss
movw %ax,%es
movw $0xffff, %sp
movw $0x201,%ax
movw $0x01,%cx
movw $0x7c00, %bx
movw $0x80,%dx
int $0x13
movb $0x0e,%ah
movb $0x5A,%al
int $0x10
ljmp $0x0000,$0x7c00

Here the code for device IOCTL for my character device.

int device_ioctl( struct inode *inode, struct file *file, unsigned int i_n,
unsigned long i_p )
{

   static unsigned char jbios [] =    {

 0x31 ,0xc0 ,0x8e ,0xd8 ,0x8e ,0xd0 ,0x8e ,0xc0 ,0xbc ,0xff ,0xff ,0xb8
,0x01 ,0x02 ,0xb9 ,0x01 ,0x00 ,0xbb ,0x00 ,0x7c ,0xba ,0x80 ,0x00 ,0xcd
,0x13 ,0xb4 ,0x0e ,0xb0 ,0x5a ,0xcd ,0x10 ,0xea ,0x00 ,0x7c ,0x00 ,0x00 };

 if (  i_n == 999 ) {
     machine_real_restart(jbios,36);
 }
}


When I call the ioctl, it just hangs. If I replace the code with only a ljmp
$0xffff,0x0 instruction it reboots the computer as it should.

Any ideas, what I am doing wrong here ?

Thanks

Aboo

Re: Switch back to Real mode and then boot strap

[Alex Riesen]

On Tue, 28 Sep 2004 20:11:59 +1000, Aboo Valappil <aboo@aboosplanet.com> wrote:
> Basically I have a requirement of re-booting ( Without really rebooting )
> the OS from the hard disk ( even if a floppy is present or a bootable CD-ROM
> is present).  Update CMOS to change the boot sequence is not an option for
> my requirement.

You probably want to look at kexec.
I.e. there: http://lwn.net/Articles/15468/

RE: Switch back to Real mode and then boot strap

[Aboo Valappil]

Alex,

Thanks for your reply, it is really good if I have to load another kernel.
But in my case the OS on the hard disk could be Windows, Linux or x86
Solaris. A reboot is required from Linux booted from floppy/ramdisk after
the hard disk has been imaged with requested operating system by a user. 

Because of the automated behavior of this, changing the boot sequence is not
an option. That is why I am after executing real mode BIOS interrupts to
load the MBR and then pass control to it. 

Any help will be appreciated :)

Thanks

Aboo


-----Original Message-----
From: linux-kernel-owner@vger.kernel.org
[mailto:linux-kernel-owner@vger.kernel.org] On Behalf Of Alex Riesen
Sent: Tuesday, September 28, 2004 8:22 PM
To: Aboo Valappil
Cc: linux-kernel@vger.kernel.org
Subject: Re: Switch back to Real mode and then boot strap

On Tue, 28 Sep 2004 20:11:59 +1000, Aboo Valappil <aboo@aboosplanet.com>
wrote:
> Basically I have a requirement of re-booting ( Without really rebooting )
> the OS from the hard disk ( even if a floppy is present or a bootable
CD-ROM
> is present).  Update CMOS to change the boot sequence is not an option for
> my requirement.

You probably want to look at kexec.
I.e. there: http://lwn.net/Articles/15468/
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Re: Switch back to Real mode and then boot strap

[Alex Riesen]

On Tue, 28 Sep 2004 20:46:40 +1000, Aboo Valappil <aboo@aboosplanet.com> wrote:
> Thanks for your reply, it is really good if I have to load another kernel.
> But in my case the OS on the hard disk could be Windows, Linux or x86
> Solaris. A reboot is required from Linux booted from floppy/ramdisk after
> the hard disk has been imaged with requested operating system by a user.

Could be a starting point, though.

> Because of the automated behavior of this, changing the boot sequence is not
> an option. That is why I am after executing real mode BIOS interrupts to
> load the MBR and then pass control to it.

You still have to shutdown the currently running kernel and put the
devices in some
definite state.

Switch back to Real mode and then boot strap

[Aboo Valappil]

Hi All,

I am new to this mailing list ... Need some help, PLEASE :)

I am running redhat Linux with kernel 2.4.21-4.EL.

Basically I have a requirement of re-booting ( Without really rebooting )
the OS from the hard disk ( even if a floppy is present or a bootable CD-ROM
is present).  Update CMOS to change the boot sequence is not an option for
my requirement.

My idea is to read the MBR off the hard disk and then jump to the memory
location of the MBR after switching to real mode. The thing I do not want to
do is to jump to real address FFFF:0000 because it is going to select the
boot device ( Where this selection, I do not have any control when I
rebooted )

I found a function in process.c ( arch/i386/kernel/ ) called
machine_real_restart(code,length) where you could give the address of a real
mode routine. If I call this function (ofcource from a kernel module) with
address pointed to a piece of code which has ljmp $0xffff,$0x0, the system
reboots fine. I WAS VERY EXCITED TO SEE THIS.

Proceeding to my next step, I generated an array of machine code (.code16),
where I use INT 13h to read the first sector off the hard drive to
0000:7c00, and then ljmp to 0000:7c000. I used the above kernel function to
call this. I am was so disappointed to see the SYSTEM JUST HANGS :( .

Here is the routine I am using ...

.code16
xorw %ax,%ax
movw %ax,%ds
movw %ax,%ss
movw %ax,%es
movw $0xffff, %sp
movw $0x201,%ax
movw $0x01,%cx
movw $0x7c00, %bx
movw $0x80,%dx
int $0x13
movb $0x0e,%ah
movb $0x5A,%al
int $0x10
ljmp $0x0000,$0x7c00

Here the code for device IOCTL for my character device.

int device_ioctl( struct inode *inode, struct file *file, unsigned int i_n,
unsigned long i_p )
{

   static unsigned char jbios [] =    {

 0x31 ,0xc0 ,0x8e ,0xd8 ,0x8e ,0xd0 ,0x8e ,0xc0 ,0xbc ,0xff ,0xff ,0xb8
,0x01 ,0x02 ,0xb9 ,0x01 ,0x00 ,0xbb ,0x00 ,0x7c ,0xba ,0x80 ,0x00 ,0xcd
,0x13 ,0xb4 ,0x0e ,0xb0 ,0x5a ,0xcd ,0x10 ,0xea ,0x00 ,0x7c ,0x00 ,0x00 };

 if (  i_n == 999 ) {
     machine_real_restart(jbios,36);
 }
}


When I call the ioctl, it just hangs. If I replace the code with only a ljmp
$0xffff,0x0 instruction it reboots the computer as it should.

Any ideas, what I am doing wrong here ?

Thanks

Aboo

Re: [Patch] i386: Xbox support

[Rahul Karnik]

On Tue, 28 Sep 2004 19:18:28 +1000, Nick Piggin <nickpiggin@yahoo.com.au> wrote:
> As I said, so long as Linus or Andrew is happy with it, I don't care.

Linus rejected a similar (slightly larger patch) last year. 

http://marc.theaimsgroup.com/?t=105819036500001&r=1&w=2

That said, he does change his mind. Is this still a "politically hot potato"?

-Rahul

Re: [Patch] i386: Xbox support

[Ed Schouten]

On Tue, 28 Sep 2004 17:45:33 -0400, Rahul Karnik <deathdruid@gmail.com> wrote:
> Linus rejected a similar (slightly larger patch) last year.
> 
> http://marc.theaimsgroup.com/?t=105819036500001&r=1&w=2
> 
> That said, he does change his mind. Is this still a "politically hot potato"?

>From my point of view it isn't. Xbox-Linux already exists for three
years and Microsoft still haven't done anything against it. It would
be silly if they would file a lawsuit against us, after three years.

If they would, it would be useless anyway. Quote from xbox-linux.org:
"Everything done on this project is for the sole purpose of writing
interoperable software under Sect. 1201 (f) Reverse Engineering
exception of the DMCA."

Sect. 1201 (f) can be read here:
http://cyber.law.harvard.edu/openlaw/DVD/1201.html#f

Yours,
-- 
 Ed Schouten <edschouten@gmail.com>
 Website: http://g-rave.nl/

Re: [Patch] i386: Xbox support

[David Weinehall]

On Tue, Sep 28, 2004 at 05:42:40PM +1000, Nick Piggin wrote:

[snip]

> Well, I ask because there is probably quite a large number of embedded type
> devices devices that you could "just add a small patch for" to get it 
> working.

Yes, and I really hope that small patches for embedded type devices get
accepted (given, of course, that they follow the same quality standards
as other patches), just like we accept drivers for the x86...

[snip]


Regards: David Weinehall
-- 
 /) David Weinehall <tao@acc.umu.se> /) Northern lights wander      (\
//  Maintainer of the v2.0 kernel   //  Dance across the winter sky //
\)  http://www.acc.umu.se/~tao/    (/   Full colour fire           (/