Subject: Re: Linux on Virtex board with ARCH=powerpc

From: Peter Mendham <[email-masked]>
Date: Wed, 25 Jun 2008 17:17:48 +0100

OK, this is all new to me, so please bear with me if I've made a major 
mistake.  I ran the kernel until it didn't give me anymore output and 
then told xmd to "stop", mrd from any location gave me exactly the same 
32-bit word of garbage.  I then reset the processor and mrd would give 
me what looked like reasonable values.  I found the __log_buf symbol in 
the System.map file (0xc024a108) and tried mrd on what I assume is the 
corresponding physical address of 0x0024a108.  I get the following:

<6>Using Xilinx Virtex machine description
<5>Linux version 2.6.26-rc6 (peter@eris) (gcc version 4.2.4) #9 PREEMPT 
Wed Jun 25 16:27:33 BST 2008
<7>Entering add_active_range(0, 0, 131072) 0 entries of 256 used
<7>Top of RAM: 0x20000000, Total RAM: 0x20000000
<7>Memory hole size: 0MB
<4>Zone PFN ranges:
<4>  DMA             0 ->   131072
<4>  Normal     131072 ->   131072
<4>Movable zone start PFN for each node
<4>early_node_map[1] active PFN ranges
<4>    0:        0 ->   131072
<7>On node 0 totalpages: 131072
<7>  DMA zone: 1024 pages used for memmap
<7>  DMA zone: 0 pages reserved
<7>  DMA zone: 130048 pages, LIFO batch:31
<7>  Normal zone: 0 pages used for memmap
<7>  Movable zone: 0 pages used for memmap
<4>Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 
130048
<5>Kernel command line: console=ttyUL0 root=/dev/xsa2 rw
<6>Xilinx intc at 0xFDFFF000C025CFFC mapped to 0x0000025d
<4>PID hash table entries: 2048 (order: 11, 8192 bytes)

xmd tells me that the processor stopped at 0xc000fe50, and subsequent 
"con" and "stop" sequences do no move this on (it reports the same each 
time). Below is a choice excerpt of my System.map:

c000fdc4 t src_error
c000fddc t dst_error
c000fdf4 T __div64_32
c000fe94 T cacheable_memzero
c000ff38 T memset

So I guess that means it's in __div64_32?

Any ideas?

Thanks in advance,
-- Peter

John Linn wrote:
> Sounds like the bootstrap loader has loaded the kernel and passed off
> execution to it, but there's no console working on the kernel.
>
> You can confirm that since you have a probe as you can dump the
> __log_buf by getting the address of it using objdump on the elf image.
> It's a pain to convert to readable form, but can help to see that things
> are indeed running. Stop the processor, then do the memory read command,
> mrd, in xmd. 
>
> For the console to work with UART Lite, CONFIG_OF must be on in the
> kernel configuration, I would check that.
>
> The file, arch/powerpc/boot/virtex.c, has the startup code for the
> virtex specific processing.  It checks to make sure there is compatible
> hardware based on the device tree.  If your device tree doesn't match
> that hardware you could have a problem.  I have not found the powerup of
> the kernel to be very informative if the device tree is wrong.
>
> I pasted in our ML405 device tree below to allow you to compare to it.
>
> Hope that helps,
> John
>
>
>
> /*
>  * (C) Copyright 2007 Michal Simek
>  *
>  * Michal SIMEK <[email-masked]>
>  *
>  * This program is free software; you can redistribute it and/or
>  * modify it under the terms of the GNU General Public License as
>  * published by the Free Software Foundation; either version 2 of
>  * the License, or (at your option) any later version.
>  *
>
>  * This program is distributed in the hope that it will be useful,
>  * but WITHOUT ANY WARRANTY; without even the implied warranty of
>  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>  * GNU General Public License for more details.
>  *
>  * You should have received a copy of the GNU General Public License
>  * along with this program; if not, write to the Free Software
>  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
>  * MA 02111-1307 USA
>  *
>  * CAUTION: This file is automatically generated by libgen.
>  * Version: Xilinx EDK 10.1.1 EDK_K_SP1.1
>  */
>
> / {
> 	#address-cells = <1>;
> 	#size-cells = <1>;
> 	compatible = "xlnx,virtex";
> 	model = "testing";
> 	DDR_SDRAM: memory@0 {
> 		device_type = "memory";
> 		reg = < 0 8000000 >;
> 	} ;
> 	chosen {
> 		bootargs = "console=ttyS0 ip=on root=/dev/ram";
> 		linux,stdout-path = "/plb@0/serial@83e00000";
> 	} ;
> 	cpus {
> 		#address-cells = <1>;
> 		#cpus = <1>;
>
> 		#size-cells = <0>;
> 		ppc405_0: cpu@0 {
> 			clock-frequency = <11e1a300>;
> 			compatible = "PowerPC,405", "ibm,ppc405";
>
> 			d-cache-line-size = <20>;
> 			d-cache-size = <4000>;
> 			device_type = "cpu";
> 			i-cache-line-size = <20>;
>
> 			i-cache-size = <4000>;
> 			model = "PowerPC,405";
> 			reg = <0>;
> 			timebase-frequency = <11e1a300>;
> 			xlnx,apu-control = <de00>;
> 			xlnx,apu-udi-1 = <a18983>;
> 			xlnx,apu-udi-2 = <a38983>;
> 			xlnx,apu-udi-3 = <a589c3>;
> 			xlnx,apu-udi-4 = <a789c3>;
> 			xlnx,apu-udi-5 = <a98c03>;
> 			xlnx,apu-udi-6 = <ab8c03>;
> 			xlnx,apu-udi-7 = <ad8c43>;
> 			xlnx,apu-udi-8 = <af8c43>;
> 			xlnx,deterministic-mult = <0>;
> 			xlnx,disable-operand-forwarding = <1>;
> 			xlnx,fastest-plb-clock = "DPLB0";
> 			xlnx,generate-plb-timespecs = <1>;
> 			xlnx,mmu-enable = <1>;
> 			xlnx,pvr-high = <0>;
> 			xlnx,pvr-low = <0>;
> 		} ;
> 	} ;
> 	plb: plb@0 {
> 		#address-cells = <1>;
> 		#size-cells = <1>;
> 		compatible = "xlnx,plb-v46-1.02.a";
> 		ranges ;
> 		IIC_EEPROM: i2c@81600000 {
> 			compatible = "xlnx,xps-iic-2.00.a";
> 			interrupt-parent = <&xps_intc_0>;
> 			interrupts = < 4 2 >;
> 			reg = < 81600000 10000 >;
> 			xlnx,clk-freq = <5f5e100>;
> 			xlnx,family = "virtex4";
> 			xlnx,gpo-width = <1>;
> 			xlnx,iic-freq = <186a0>;
> 			xlnx,scl-inertial-delay = <0>;
> 			xlnx,sda-inertial-delay = <0>;
> 			xlnx,ten-bit-adr = <0>;
> 		} ;
> 		LEDs_4Bit: gpio@81400000 {
> 			compatible = "xlnx,xps-gpio-1.00.a";
> 			interrupt-parent = <&xps_intc_0>;
> 			interrupts = < 5 2 >;
> 			reg = < 81400000 10000 >;
> 			xlnx,all-inputs = <0>;
> 			xlnx,all-inputs-2 = <0>;
> 			xlnx,dout-default = <0>;
> 			xlnx,dout-default-2 = <0>;
> 			xlnx,family = "virtex4";
> 			xlnx,gpio-width = <4>;
> 			xlnx,interrupt-present = <1>;
> 			xlnx,is-bidir = <1>;
> 			xlnx,is-bidir-2 = <1>;
> 			xlnx,is-dual = <0>;
> 			xlnx,tri-default = <ffffffff>;
> 			xlnx,tri-default-2 = <ffffffff>;
> 		} ;
> 		RS232_Uart: serial@83e00000 {
> 			compatible = "ns16550";
> 			device_type = "serial";
> 			interrupt-parent = <&xps_intc_0>;
> 			interrupts = < 6 2 >;
> 			reg = < 83e00000 10000 >;
> 			reg-offset = <3>;
> 			reg-shift = <2>; 
> 			clock-frequency = <05f5e100>;
> 			xlnx,family = "virtex4";
> 			xlnx,has-external-rclk = <0>;
> 			xlnx,has-external-xin = <0>;
> 			xlnx,is-a-16550 = <1>;
> 		} ;
> 		SysACE_CompactFlash: sysace@83600000 {
> 			compatible = "xlnx,xps-sysace-1.00.a";
> 			interrupt-parent = <&xps_intc_0>;
> 			interrupts = < 3 2 >;
> 			reg = < 83600000 10000 >;
> 			xlnx,family = "virtex4";
> 			xlnx,mem-width = <10>;
> 		} ;
> 		TriMode_MAC_GMII: xps-ll-temac@81c00000 {
> 			#address-cells = <1>;
> 			#size-cells = <1>;
> 			compatible = "xlnx,compound";
> 			ethernet@81c00000 {
> 				compatible = "xlnx,xps-ll-temac-1.01.a";
> 				device_type = "network";
> 				interrupt-parent = <&xps_intc_0>;
> 				interrupts = < 2 2 >;
> 				llink-connected = <&PIM2>;
> 				local-mac-address = [ 02 00 00 00 00 01
> ];
> 				reg = < 81c00000 40 >;
> 				xlnx,bus2core-clk-ratio = <1>;
> 				xlnx,phy-type = <1>;
> 				xlnx,phyaddr = <1>;
> 				xlnx,rxcsum = <0>;
> 				xlnx,rxfifo = <1000>;
> 				xlnx,temac-type = <1>;
> 				xlnx,txcsum = <0>;
> 				xlnx,txfifo = <1000>;
> 			} ;
> 		} ;
> 		mpmc@0 {
> 			#address-cells = <1>;
> 			#size-cells = <1>;
> 			compatible = "xlnx,mpmc-4.00.a";
> 			PIM2: sdma@84600100 {
> 				compatible = "xlnx,ll-dma-1.00.a";
> 				interrupt-parent = <&xps_intc_0>;
> 				interrupts = < 1 2 0 2 >;
> 				reg = < 84600100 80 >;
> 			} ;
> 		} ;
> 		xps_bram_if_cntlr_1: xps-bram-if-cntlr@ffffe000 {
> 			compatible = "xlnx,xps-bram-if-cntlr-1.00.a";
> 			reg = < ffffe000 2000 >;
> 			xlnx,family = "virtex4";
> 		} ;
> 		xps_intc_0: interrupt-controller@81800000 {
> 			#interrupt-cells = <2>;
> 			compatible = "xlnx,xps-intc-1.00.a";
> 			interrupt-controller ;
> 			reg = < 81800000 10000 >;
> 			xlnx,num-intr-inputs = <7>;
> 		} ;
> 	} ;
> 	ppc405_0_dplb1: plb@1 {
> 		#address-cells = <1>;
> 		#size-cells = <1>;
> 		compatible = "xlnx,plb-v46-1.02.a";
> 		ranges ;
> 	} ;
> }  ;
>
>
>
>
>
> -----Original Message-----
> From: Peter Mendham [mailto:[email-masked]] 
> Sent: Tuesday, June 24, 2008 1:21 PM
> To: John Linn
> Cc: [email-masked]
> Subject: Re: Linux on Virtex board with ARCH=powerpc
>
> Hi John,
>
> Thanks for your reply, that's really helpful.  I'm actually using the 
> mainline kernel, rather than the one from the xilinx git tree, but your 
> information has really moved me on.  My first problem was that the 
> Xilinx utility (from the git tree) for device tree dts generation didn't
>
> insert a "linux,stdout-path" node under "chosen".  I spotted that the 
> ml403 example had this, so after adding it I got early console 
> messages.  Everything now grinds to a halt after I get the message "flat
>
> tree at 0x40ad60" which is just before it calls the kernel, so I assume 
> it's that call that is killing it.  I have "console=ttyUL0" for my 
> uartlite, so I should be getting messages, shouldn't I?  Do you know 
> where the next execution point is?  Maybe I could find out where it's 
> getting stuck.
>
> I haven't managed to generate an ACE file, I'm just loading the kernel 
> image from xmd ATM, genace won't play ball for me, it complains about 
> -board user not being valid, it won't even run on the examples copied 
> directly from the user manual.  Anyway, I think genace is a bit OT, and 
> I can manage with xmd for now.
>
> Thanks,
> -- Peter
>
> John Linn wrote:
>   
>> Hi Peter,
>>
>> I'm not up on what can be done with the simple image you refer to in
>>     
> 1.
>   
>> I'm sure I should be, but there's a lot to learn.
>>
>> With regards to 2, the elf image, zImage (without the elf extension),
>>     
> is
>   
>> located in arch/powerpc/boot.
>>
>> You can make a SystemACE file from that elf image just as you did in
>> arch/ppc.  We have a default device tree file, ml405.dts, in the
>> arch/powerpc/boot/dts directory for our ml405 board. The kernel
>> configuration has a config, DEVICE_TREE, that specifies the name of
>>     
> the
>   
>> device tree file. I normally compile the device tree into the kernel
>> which is the default build, make ARCH=powerpc zImage. That image does
>> not require a boot loader.
>>
>> I inserted the text below from a document that I have about building
>>     
> the
>   
>> arch/ppc and arch/powerpc kernels.
>>
>> Hope that helps,
>> John
>>
>>
>> Notation
>>
>> The phrase "<ppc or powerpc>" is used throughput the text and means
>>     
> that
>   
>> one or the other, "ppc" or "powerpc" is to be typed depending on the
>> architecture you are building.
>>
>> Commands that are used in a bash shell are preceded by ">".
>>
>> Getting Ready To Build the Kernel
>>
>> This assumes you installed the ELDK tools and assumes you'll be using
>>     
> a
>   
>> bash shell.
>>
>>   
>>     
>>> bash
>>> export CROSS_COMPILE=ppc_4xx-
>>>     
>>>       
>> Setting Up the Kernel Tree
>>
>> If you have previously built this kernel for another architecture, ppc
>> or powerpc, then the tree needs to be setup correctly for the new
>> architecture.  Assuming you have not previously built it, this does
>>     
> not
>   
>> need to be done.
>>
>>   
>>     
>>> make ARCH=<ppc or powerpc> mrproper
>>>     
>>>       
>> Configuring the Kernel
>>
>> The kernel should be configured to run on the ML405 or ML507 board
>>     
> from
>   
>> Xilinx. 
>> 	
>>   
>>     
>>> make ARCH=<ppc or powerpc>  ml405_defconfig
>>>     
>>>       
>> or 
>>
>>   
>>     
>>> make ARCH=<ppc or powerpc> ml507_defconfig
>>>     
>>>       
>> Building the Kernel
>>
>> The following command will build the Linux kernel assuming you are in
>> the root directory of the kernel.  The root directory of the kernel
>>     
> from
>   
>> the Xilinx Git tree is linux-2.6-xlnx. An elf file, zImage.elf, is
>> created in the arch/ppc/boot/images directory for ppc architecture. An
>> elf file, zImage, is created in the the arch/powerpc/boot directory
>>     
> for
>   
>> the powerpc architecture.
>>
>>   
>>     
>>> make ARCH=<ppc or powerpc> zImage
>>>     
>>>       
>> 	
>> Building the Kernel With Ramdisk
>>
>> A ram disk image, a file named *.gz, must be placed into the
>> arch/ppc/boot/images or arch/powerpc/boot directory, depending on the
>> architecture, prior to building the kernel.
>>
>>   
>>     
>>> make ARCH=<ppc or powerpc> zImage.initrd
>>>     
>>>       
>> An elf file, zImage.initrd.elf, is created in arch/ppc/boot/images
>> directory for the ppc architecture. An elf file file, zImage.initrd,
>>     
> is
>   
>> created in arch/powerpc/boot directory for the powerpc architecture.
>>
>> Generating An Ace File
>>
>> The elf file generated for the kernel and the bit stream can be
>>     
> combined
>   
>> to create an ACE file for compact flash.  The following assumes a bash
>> shell where XMD is accessible and a xilinx probe attached to the board
>> for which you are generating an ace file.
>>
>>   
>>     
>>> xmd -tcl genace.tcl -jprog -target ppc_hw -hw <bit file name> -elf
>>>       
> <elf
>   
>>>     
>>>       
>> file name> -board <ml405 or ml507> -ace <desired ace file name>
>>
>> -----Original Message-----
>> From: linuxppc-embedded-bounces+john.linn=[email-masked]
>> [mailto:linuxppc-embedded-bounces+john.linn=[email-masked]] On
>> Behalf Of Peter Mendham
>> Sent: Tuesday, June 24, 2008 3:02 AM
>> To: [email-masked]
>> Subject: Linux on Virtex board with ARCH=powerpc
>>
>> Dear all,
>>
>> I'm trying to boot a 2.6.26-rc6 kernel on a custom Virtex 4 board.  I 
>> have used the Xilinx utility to generate a device tree and now want to
>>     
>
>   
>> generate an image for throwing onto CF for use with a SystemACE (just 
>> like on the the ML3/4xx boards).  I don't want to use a bootloader (I 
>> don't really need one).  I saw something on this list about
>>     
> simpleImage,
>   
>> "simple" sounded good to me so I thought I'd try that (or did I 
>> misinterpret what this is for?).  I also don't want the image to be
>>     
> too 
>   
>> big, I always used to use a zImage under ARCH=ppc. So, two questions, 
>> which hopefully are easy ones:
>> 1. I did what Grant said in a post to this list about simpleImage, and
>>     
>
>   
>> dumped my dts into arch/powerpc/boot/dts and I called it system.dts
>>     
> (for
>   
>> now).  I then tried to do make simpleImage.system which ran right 
>> through to final link then moaned about a missing simpleboot-system.  
>> Where is this supposed to come from?  What am I doing wrong?  I
>>     
> naively 
>   
>> tried copying simpleboot.o to simpleboot-system.o and the error went 
>> away.  Hmm.
>> 2. I need an ELF to give to my SystemACE file generator.  This used to
>>     
>
>   
>> pop up in arch/ppc/boot/images and be called zImage.elf, which made 
>> sense to me.  What's the deal now with powerpc?  What should I be
>>     
> using?
>   
>> Finally, can anyone give me a heads-up on any gotchas with what I'm 
>> trying to do.  As you can tell, I don't entirely know what I'm doing,
>>     
> so
>   
>> any pointers would be gratefully received.
>>
>> Thanks,
>> -- Peter
>>
>>
>> The University of Dundee is a Scottish Registered Charity, No.
>>     
> SC015096.
>   
>> _______________________________________________
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>>
>>
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>
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