On Wed, May 25, 2011 at 7:16 AM, Gabbasov, Andrew
[off-list ref] wrote:
Hello Matthew,
You have made a patch
"powerpc/fsl_booke:=A0Add=A0support=A0to=A0boot=A0from=A0core=A0other=A0t=
han=A00" some time
ago, so you probably worked with booting the kernel on a cpu subset,
particularly on the core other than 0.
Could you please describe any details how you ran the kernel from u-boot =
on
a non-0 cpu?
I did this via kexec not via u-boot. In this method I would reboot on
any one of the cores and it would bring up the other cores.
I have a problem trying to boot linux on p4080ds platform on any non-0 cp=
u
(as a first step to running AMP or mixed AMP/SMP configuration). I'm tryi=
ng
to run 2.6.34.6 kernel with some Freescale patches in SMP configuration w=
ith
full original device tree and device tree with some cpu nodes removed. I'=
m
using the u-boot script, shown at the bottom of this message.
If I run "bootm go" after the script commands (thus running the kernel on
cpu 0), the kernel runs fine.
When I'm trying to run the SMP kernel with full device tree on cpu 1 usin=
g
the following commands after the script:
=A0 fdt boot 1
=A0 cpu 1 release 0 1 c00000 -
the kernel begins to run, but soon crashes. Possible reasons
are:=A0"Unrecoverable FP Unavailable Exception", at nearly random
place;=A0memory allocation errors somewhere in DPAA=A0code and then segme=
ntation
fault (sig 11); unknown exception (sig 4).=A0Sometimes it doesn't even sh=
ow
anything on the console (too early exception?), but sometimes it boots
successfully up to the shell prompt.
Is the single core boot stable at this point?
When I'm trying to run the SMP kernel with the device tree with cpu 0
stripped out (commented out the whole cpu0 node and all properties referr=
ing
to it with &cpu0), using the following commands after the script:
=A0 fdt boot 1
=A0 cpu 1 release 0 0 c00000 -
=A0 [Note the difference in the parameter to 'cpu 1 release' command,
=A0=A0=A0 it should be a logical cpu number, which is different]
the result is almost the same, the kernel crashes too. The reasons are
similar to the above, with more often "Unrecoverable FP Unavailable
Exception".
Can you send me the kernel boot logs and kernel defconfig? (off list perhap=
s)
Can you give any advise why can this happen, and what I could be doing
wrong?
Did you build your kernel relocatable? Did you use the -b option when
compiling your device tree? We do have a hypervisor for this part
which might be a more suitable and tested solution depending on what
you are trying to accomplish. I'm not sure that anyone has explicitly
tested AMP on a p4080.
-M=