Hi all, I am currently working on a PPC440SPe based custom board to bring up the System ACE interface from Linux. I am using linux-2.6.16 with the patch applied as per Ameet's suggestion from the following link https://www.cs.york.ac.uk/rtslab/demos/amos/xupv2pro/patches/linuxppc-2.6.17 .1-sysace-1.1.patch We are able to access the controller registers from u-boot, but kernel throws a "Data Machine Check exception" while accessing the registers. 1. I have set up System ACE base address as 0xE000_0000 (which is the same as in u-boot). 2. As far as I understand, kernel should pick-up TLB settings from u-boot. 3. But , while debugging through BDI this is what I observe: TLB entry Listings from u-boot: IDX TID EPN SIZE VTS RPN USER WIMGE USRSVC 0 : 00 ff000000 16MB V0 -> 4_ff000000 U:0000 WI-G- XWRXWR 1 : 00 00000000 256MB V0 -> 0_00000000 U:0000 -I-G- XWRXWR 2 : 00 10000000 256MB V0 -> 0_10000000 U:0000 -I-G- XWRXWR 3 : 00 20000000 256MB V0 -> 0_20000000 U:0000 -I-G- XWRXWR 4 : 00 30000000 256MB V0 -> 0_30000000 U:0000 -I-G- XWRXWR 5 : 00 90000000 256KB V0 -> 4_00000000 U:0000 -I--- XWRXWR 6 : 00 e0000000 1KB V0 -> 4_e0000000 U:0000 -I-G- XWRXWR Note : 6th entry is for system ACE. TLB entry Listings from Kernel: IDX TID EPN SIZE VTS RPN USER WIMGE USRSVC 0 : 00 00000000 1KB -0 -> 4_ff000000 U:0000 WI-G- XWRXWR 1 : 00 fdfff000 4KB V0 -> 4_f0000000 U:0000 -IMG- ----WR 2 : 00 fdffe000 4KB V0 -> 4_f0000000 U:0000 -IMG- ----WR 3 : 00 fdffd000 4KB V0 -> 4_f0000000 U:0000 -IMG- ----WR 4 : 00 e1000000 4KB V0 -> 0_e0000000 U:0000 -IMG- ----WR 5 : 00 00000000 1KB -0 -> 4_00000000 U:0000 -I--- XWRXWR 6 : 00 00000000 1KB -0 -> 4_e0000000 U:0000 -I-G- XWRXWR Note: 4th entry is system ACE. The RPN and access permissions are totally different for System ACE from u-boot and kernel. I u-boot it is - 4_e0000000 , and in kernel it is 0_e0000000 I think this is the issue, causing exception during writes to registers from kernel. Could someone throw some light on this area? This is very critical for us now. Or am I missing something? Any help would be appreciated. Thanks in advance Junita -------------- next part -------------- An HTML attachment was scrubbed... URL: http://ozlabs.org/pipermail/linuxppc-embedded/attachments/20060831/819dcdc3/attachment.htm
