Your problem seems to be due to the CPU_213 errata: ftp://ftp.xilinx.com/pub/documentation/misc/ppc405f6v5_2_0.pdf, page 22
Best regards, Andrei David H. Lynch Jr wrote: > I am working through bringing up Linux 2.6.13.4 on a Xilinx V4 based > ppc405. > with memory from 0x0 through 0x7fffffff > > > > Right now I get: > > >Starting MonitorX.elf: V3.3.2.0. > > > >loaded at: 00400000 0047F13C > >board data at: 0047D128 0047D13C > >relocated to: 00405300 00405314 > >zimage at: 00405A95 0047CE71 > >avail ram: 00480000 08000000 > > > >Linux/PPC load: console=ttyS0,9600 console=tty0 init=/linuxrc > looptype=squashfs cdroot splash=silentttttt > >Uncompressing Linux......done. > >Now booting the kernel > > I have been able to trace execution into head_4xx.S to immediately > before turn_on_mmu: > But immediately after this I lose the ability to trace. > > I have been tracing things with a status port at 0x70000000 I can write > to and read from the host side with code like > > lis r14,0x7000 /* debugging port */ > li r15,0x2305 /* value to output */ > stw r15,4(r14) eieio > > after turn_on_mmu executes this does not seem to work. > looking at other code it appeared that I needed to add > tophy(r14,r14) prior to the stw > but that does not seem to help. > > What do I need to do to be able to continue to use my debug port ? > > > _______________________________________________ > Linuxppc-embedded mailing list > Linuxppc-embedded at ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-embedded
