I'm trying to get a BDI2000 (firmware v1.09) working in order to debug a kernel module. I'm using an Embedded Planet RPXlite MPC850 board running kernel v2.4.20 from kernel.org with CONFIG_BDI_SWITCH=y and CONFIG_COMPILE_OPTIONS="-g -ggdb" in my .config
I have compiled gdb v5.3 with --host=i686-pc-linux-gnu --target=powerpc-linux. The relevant bit of my BDI config file is here: ===================================================================== WSPR 796 0x00000000 ;;M_TWB: invalibdate TWB WM32 0x000000f0 0x00000000 ;;invalidate page table base (PTBASE) [TARGET] CPUTYPE MPC800 CPUCLOCK 50000000 ;the CPU clock rate after processing the init list WORKSPACE 0x00000000 ;workspace in target RAM for fast download BDIMODE AGENT ;the BDI working mode (LOADONLY | AGENT) BREAKMODE SOFT ;SOFT or HARD, HARD uses PPC hardware breakpoints MMU XLAT ; Enable address translation ====================================================================== I have scanned the archives of this mailing list and have seen a number of messages relating to getting the BDI working with the MMU but I don't seem to be able to get this working on my system. My kernel is stored in flash and booted by u-boot v0.3.0 I start the system by telneting into the BDI and issuing: BDI>bi 0xc0000000 0xc00fffff BDI>go U-boot starts, loads the kernel and it is decompressed. At this point the system stops. I then do the following: BDI>ci BDI>mm 0xf0 0xc014f000 (gdb) target remote 192.168.240.242:2001 Remote debugging using 192.168.240.242:2001 0xc00020f0 in start_here() (gdb) c Continuing. Everything is OK until after I get a login prompt. After I log in, I don't seem to be able to debug successfully. I'm wanting to break on a call from a user-space program to a kernel function. On executing the program that triggers the kernel breakpoint I get the following error in the telnet session to the BDI *** MMU: address translation for 0xC400E69C failed ... *** MMU: address translation for 0xC0A05EF0 failed etc.. and in dgb: (gdb) Cannot remove breakpoints because program is no longer writeable. It might be running in another process. Further execution is probably impossible. Breakpoint 3, m8xx_cpm_dpalloc (size=16) at commproc.c:216 (gdb) bt Cannot access memory at address 0xc0a05ef0 Am I missing something obvious ? Is this the right way to go about debugging a loadable module ? Any help would be gratefully appreciated. Cheers Jeremy ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
