Minimum Hardware requirement for Linux porting

[haichithunta]

Hi we developed custom Virtex4-FX60 board .It has SDRSDRAM(32Mb) and UART no other storage such as Flash Ic or Compact flash card.

my question is that is it possible to port linux (open source 2.4 or 2.6). I am downloading u-Boot ,kernel image and rootfile system through jtag in to SDRSDRAM and then running the linux 

 is it possible for my hardware requirement

[linnj]

Yes it's possible to use the Linux kernel with just ram.  Yes you download the kernel thru the jtag.

Please checkout http://xilinx.wikidot.com as there's a powerpc kernel page there with explanation.

I would seperate all the those steps, 1. make sure the kernel you build boots 2. then load u-boot and try to load a kernel. 

Thanks.

[haichithunta]

Hi thanks for replay

 I create  hardware ie one uart and 1 SDRSDRAM interface with PICKUP  and download it into virtex4 

my question is how can i download Boot and zImage and Rootfile system into sdram and execute that.

please replay

[linnj]

Are you really sure you did your homework as that's all spelled out on the wiki page at http://xilinx.wikidot.com/powerpc-linux?

[sanjeevnaik_kumta@yahoo.co.in]

zImage starting: loaded at 0x00400000 (sp: 0x005b0eb0)
Allocating 0x392f8c bytes for kernel ...
gunzipping (0x00000000 <- 0x0040c000:0x005afb35)...done 0x37202c bytes

Linux/PowerPC load: console=ttyUL0 root=/dev/ram
Finalizing device tree... flat tree at 0x5bd300

Afterword i am not getting any result on hyperterminal

1)i am using uartlite with 9600 without any parity with interrupt

2)i used sdr sdram to run linux kernal

3)i generate the device tree using device tree generator tool (attached the file)

4)then copy the virtex405-my.dts to /arch/powerpc/boot/dts

5)the i edit the virtex4_defconfig

CONFIG_CMDLINE="console=ttyUL0 root=/dev/ram"
CONFIG_EXTRA_TARGETS="simpleImage.virtex405-my simpleImage.initrd.virtex405-my"

 the using

make 40x/virtex4_defconfig config the kernal

then generate simpleImage.virtex405-my.elf using make ARCH=powerpc simpleImage.virtex405-my

6)the usig $XMD i down load the simpleImage.virtex405-my.elf

and run then i got the o/p on hyperterminal

zImage starting: loaded at 0x00400000 (sp: 0x005b0eb0)
Allocating 0x392f8c bytes for kernel ...
gunzipping (0x00000000 <- 0x0040c000:0x005afb35)...done 0x37202c bytes

Linux/PowerPC load: console=ttyUL0 root=/dev/ram
Finalizing device tree... flat tree at 0x5bd300

 and after i am not getting any thing 

i am using denx ELDK4.2

please help me to resolv the problem

[jpl@xiphos.ca]

Are you able to examine memory after the linux has "finished" booting, for example with 'xmd'?

I have found the instructions at http://xilinx.wikidot.com/debugging-kernel-boot-problems#toc2 to be very helpful when there is no console output.  Specifically,  the part about finding __log_buf and reading it afterwards. 

[sanjeevnaik_kumta@yahoo.co.in]

Hi i attached my device tree  please tell me using sdr sdram is it possible to boot linux on powerpc

[jpl@xiphos.ca]

Did you get u-boot working as suggested by John?  Perhaps you should try putting some simple code into block ram (using XPS or XPS-SDK) and attempt to access the SDRAM to make sure that your memory access is functional.

I'm not an expert in all the possible permutations of the .dts file, but if you are generating it from XPS then you shouldn't have a problem.  Does it match your .mhs file? 

Joshua 

[linnj]

Did you also use the wiki to dump the log_buf to see what happened when you booted, like Joshua recommended?

When things don't work, you'll have to dig in deep to understand why.  As long as SDRAM works the kernel should work. 

Did you compare your dts file to the one for the ml405 in the kernel tree (arch/powerpc/boot/dts)?

[linnj]

Have you ran stand alone (no os) apps on this from the EDK?

That's a good step on a new h/w system before trying to run the kernel also.

[sanjeevnaik_kumta@yahoo.co.in]

Hi i solved problem

[linnj]

Can you be more specific on what problem was solved and how so that others can benefit from it?

That's the idea of the threads, so there's a history that can be searched and we don't have to repeat every problem.

Thanks.