re: PPC405 system slow boot

hi!

i've recently had a similar situation with a XC2VP50-based custom board.
There was no SystemACE involved, we load the FPGA via a CPLD/serial =
flash.

the problem resided in the interrupt controller, which was not able to =
enable interrupts due to an error in the MHS file.
you should check that your interrupt controller section includes the =
following parameters:
PARAMETER C_HAS_IPR =3D 1
PARAMETER C_HAS_SIE =3D 1
PARAMETER C_HAS_CIE =3D 1
PARAMETER C_HAS_IVR =3D 1

the intc driver uses SIE and CIE to atomically enable and disable =
interrupts.
when the uartlite interrupt was not enabled, the uartlite driver =
encountered timeouts which caused single characters to appear at the =
serial console, similar to what you described.

hope that helps,
arvid staub


________________________________________
Von: linuxppc-embedded-bounces+arvid.staub=3Dmediornet.com@ozlabs.org =
[mailto:linuxppc-embedded-bounces+arvid.staub=3Dmediornet.com@ozlabs.org]=
 Im Auftrag von Clint Thomas
Gesendet: Montag, 28. August 2006 21:57
An: linuxppc-embedded@ozlabs.org
Betreff: PPC405 system slow boot

Hey guys,

I've run through the loops to try and figure what could be wrong with =
this system. The board in question is modeled after the Xilinx ML300 =
board. It uses a Xilinx System ACE chip to load a FPGA / Kernel image =
from compact flash. Originally, I was trying to use the CompactFlash as =
the root file system, but because of issues in either the design or =
software, this would only work if SysAce was in polled I/O mode. To =
circumvent this, I built my root filesystem into an initrd image and =
built a single ELF file with the Kernel and RFS, then strapped that to =
the FPGA bit file to make a single FPGA/Kernel/RFS SysAce file.

Upon decompression, the Linux kernel boots quickly and loads all of the =
device drivers. However when it gets to the prompt, it starts slowing =
down. Output and input to and from the board becomes very very slow (it =
displays 2 characters roughly every 20 seconds). Originally I believed =
this to be the CPU still polling SystemAce, so I disabled the Linux =
System ACE drivers to remove that as a possibility, however after doing =
this, the problem still persists, even with the RFS in ram! Has anybody =
encountered a similar situation to this before, with possible insight =
towards a solution? Thank you for your time.
=A0
Clinton Thomas
cthomas@soneticom.com
=A0