I am using codewarrior and USB+TAP for debugging(didn't got BDI yet). One problem seems like if i set a break point at some place, when the code reach there, it did stopped, but the instruction on that location became 0x00000000 ! Any also, the kernel is loaded at physical address 0x0, how do i set the break point to 0xC000XXX address? I suppose i should set the break point at the physical address instead. I don't have the hardware to try right now.
Thank you for your reply! lei On 11/16/06, Steven Blakeslee <[EMAIL PROTECTED]> wrote: > Generally stepping over the rfi command will cause the problem. > Instead, set a breakpoint at the address that the rfi command will jump > to, the C000XXX address. Then step through code from then on. > > > > > -----Original Message----- > > From: > [EMAIL PROTECTED] > > [mailto:linuxppc-embedded- > > [EMAIL PROTECTED] On Behalf Of Lei Sun > > Sent: Thursday, November 16, 2006 10:45 AM > > To: [email protected] > > Subject: memory corruption after MMU turned on > > > > Hi all: > > I am trying to bring up customized board based on MPC8270, the > > kernel version is 2.4.30, it works fine on one of the Eval board > > (PQ2FADS-VR, which use MPC8275). > > The kernel hangs after uncompressing is done, further debug shows > > that it hangs right after "rfi " instruction of the turn_on_mmu: > > function in head.S > > > > turn_on_mmu: > > 240 mfmsr r0 > > 241 ori r0,r0,MSR_DR|MSR_IR > > 242 mtspr SRR1,r0 > > 243 lis r0,[EMAIL PROTECTED] > > 244 ori r0,r0,[EMAIL PROTECTED] > > 245 mtspr SRR0,r0 > > 246 SYNC > > 247 RFI /* enables MMU */ > > > > After i step over the RFI instruction, the PC points to C000XXX , but > > all memory content is 0 by then. > > my BATU0 is 0xC000FFE0 BATL0 is 0x00000002, I have 128MB RAM. The > > u-boot works fine, without MMU turned on. We do have some hardware > > problem, such that i have to lower the bus frequency to make the SDRAM > > stable. What physical parameter could cause the board not working with > > MMU on? > > > > Any suggestion? > > > > Thanks > > lei > > _______________________________________________ > > Linuxppc-embedded mailing list > > [email protected] > > https://ozlabs.org/mailman/listinfo/linuxppc-embedded > _______________________________________________ Linuxppc-embedded mailing list [email protected] https://ozlabs.org/mailman/listinfo/linuxppc-embedded
