PPC405 system slow boot

[Arvid Staub]

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 = 1
PARAMETER C_HAS_SIE = 1
PARAMETER C_HAS_CIE = 1
PARAMETER C_HAS_IVR = 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=mediornet.com at ozlabs.org [mailto:linuxppc-embedded-bounces+arvid.staub=mediornet.com at ozlabs.org] Im Auftrag von Clint Thomas
Gesendet: Montag, 28. August 2006 21:57
An: linuxppc-embedded at 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.
 
Clinton Thomas
cthomas at soneticom.com