After reading Stefan's mention of F0 index 52h in the CS5530A, I think I'm begining to understand the problem.
Currently, F0000h is mapped to flash. This is because at reset, the CS5530A decodes that address block and claims those cycles, generating an ISA bus memory cycle specifically. I think the cs5530a only claims read cycles. So I think what I need to do is to do the copy to F0000h like normal in copy_pirq_routing_table. Then, before verify_copy_pirq..., I need to tell the CS5530A to no longer claim read cycles for that address block. But... that might not be possible. Looking at Stefan's /dev/bios code I see the use of 6 to enable write access to the flash. But I don't see the ability to disable the CS5530A's claim of the read cycle. So no way to map F0000 elsewhere. So in summary, I think there is no way to tell the gx1+cs5530a combo that F0000h should be mapped to sdram. Since that can't be done, then it would require that the PIRQ table be stored uncompressed somewhere in the F0000-100000 adress range. And that's what happens when building with CONFIG_COMPRESS=0 which does work of course since eventually the kernel finds it somewhere within the address range using the $PIRQ signature. But that feels dirty to me. So what do you guys think I should do? Do you agree with my assessment above? The easiest thing to do would be to add a linux kernel boot parameter that'll allow LinuxBIOS to tell filo to tell the kernel exactly where in sdram the uncompressed PIRQ table is. I think I can do that. Alternately, since we know that F0000h is the start of the flash, could we just reserve that small section of flash for storing an uncompressed PIRQ table and leave everything else as is. I like the feel of that except I don't really now how all the linkage and addressing is assigned. Please let me know what you think. Thanks, Ramesh --- "Ronald G. Minnich" <rminnich@lanl.gov> wrote: > > > On Fri, 4 Mar 2005, Ronald G. Minnich wrote: > > > > > > > On Thu, 3 Mar 2005, ramesh bios wrote: > > > > > Ok, so I tried this specific sequence and it > failed. > > > > > > making region read/write > > > > nope. you need to make it write-only, > > arg, I'm not thinking, we are running out of high > memory and then RAM. > > So making it read/write should have worked. Blash. > > Dump the memory at 0xf0000 BEFORE and AFTER you copy > the PIRQ. > > ron > _______________________________________________ > Linuxbios mailing list > Linuxbios@clustermatic.org > http://www.clustermatic.org/mailman/listinfo/linuxbios > __________________________________ Celebrate Yahoo!'s 10th Birthday! Yahoo! Netrospective: 100 Moments of the Web http://birthday.yahoo.com/netrospective/ _______________________________________________ Linuxbios mailing list Linuxbios@clustermatic.org http://www.clustermatic.org/mailman/listinfo/linuxbios
