dual core ppc

[xtracool_protik]

Hey guys,

 As I understand V2P have 2 physical ppc

 I managed to get single ppc up and ported linux kernel over it with initrd support.

 Here are few things which I'll like to try:

 1. How to get console on monitor instead of serial (I suppose adding video support and modifying kernel bootargs will be sufficient).

 2. Board doesn't have cache coherency supported so is there a way to add cache coherency say through use of external DDR RAM?

3. If not is there a way to get dual core ppc working and compilation of linux kernel for same?

4. If even not that is there a way to have one processor (on plb0) working under linux and another without linux and bth working together somehow(on plb1)

I'm trying to understand purpose of 2 physical processors on board if they can't be used together how else can I put them to use efficiently?

Thanks

[linnj]

1. You can look at the wiki for the video frame buffer driver, but you need the h/w design to support it.

2. I wouldn't want to try to add cache coherency.

3. sure, but haven't done it, might be some app notes on it.

4. should work, haven't done it.

Most customers weren't doing that is the reason I don't also.

Thanks.

[xtracool_protik]

Thanks John,

 Sorry I was busy for last 1-2 days.

 So I've decided to go one step at a time:

 Adding vga support. I tried getting 256 MB Single Rank DDR Memory with VGA Controller from http://www.xilinx.com/univ/xupv2p_demo_ref_designs.htm just to get a design idea however it gave me few errors about missing IPs.

 I went ahead and added tft IP to my existing design assigned address size of 64MB and put it SPLB and MPLB on plb0

 However I'm not very sure (confident) about it. I would like community opinion, Thanks.

 If I'm going in right direction can I as serial console with tft console?

 just by replacing RS232_Uart_1 by xps_tft_0 

 not sure what should be replacement for /dev/ttyUL0 

[linnj]

http://xilinx.wikidot.com/osl-tft-driver

Here's a limited amount of information about the testing.

Thanks.

[xtracool_protik]

Thanks John I'll see through it and report back :)

 My next task is: Can I build rootfs instead of initramfs

 Or can I get initramfs to boot as RW fs just by specifying root=/dev/ram rw?

Regards

Pratik

[xtracool_protik]

Hi,

Ok so I've been trying to get video working for 2 days now with failure

I suppose I've added proper IP and port connections as I see monitor detection, however as I add console=/dev/tty0 to bootargs it doesn't help.

Should I try console=/dev/tty0, 640x480@60, 6, 2097152 (640x480@60Hz 6bit color depth and 2MB frame buffer) ?

I tried it once but it didn't do anything as such

 If its required I can add ucf, mhs and mss files to look into

Thanks for any hint that anyone can provide

Regards

Pratik

[jpl@xiphos.ca]

Excuse me for this slightly pedantic response, and perhaps it was just a transcription error, but in your kernel command line, make sure you don't have any spaces between arguments for console=.

For example, the following syntax is okay:

console=/dev/tty0,640x480@60,6,2097152

The following syntax (copied and pasted from your post) is not okay:

console=/dev/tty0, 640x480@60, 6, 2097152

I've not used video console from an embedded linux device, so I can't comment on actual validity of these arguments.

You had an earlier question about SMP linux on dual-PPC Virtex devices.  I was of the impression that this isn't possible due to the lack of some sort of ioapic/cache-coherency layer to allow the two CPU's to get along.  However, I haven't looked into this to any depth.  I'd be interested to hear if you get anywhere with it.

Joshua