ATUM4>mdh 0xfff80000 0_fff80000 : 2705 1956 552d 426f 6f74 2031 2e33 2e30 '..VU-Boot 1.3.0
ATUM4>bi 0xfffff01c Breakpoint identification is 0 ATUM4>go 0xfff80000 ATUM4>halt Target CPU : MPC85xx (e500v2 rev.2) Target state : halted Debug entry cause : COP halt Current PC : 0xf0000000 Current CR : 0x00000000 Current MSR : 0x00000200 Current LR : 0x00000000 Current CCSRBAR : 0x0_e0000000
This cannot work, as your own memory dump shows (above). You have the "magic word" and some ASCCI string at 0xfff80000. These are not valid ppc assembler instructions, but the begin of the u-boot image. Please check/dump address 0xfffffffc. There should be a valid jump instruction (see resetvec.S) which jumps to an address within a 4kbyte page at the end of the address space. ((0xfffff000, _start_e500()). There will be code that initializes the MMU that you can access the rest of the flash device(s), including the u-boot image (e.g cpu_init_f().
In a nutshell I'm trying to figure out what the pc is doing and why - I can't hit breakpoints nor see any signs of code running. The docs do say:
4.4.3.3 Boot ROM Location The MPC8548E defines the default boot ROM address range to be 8 Mbytes at address 0x0_FF80_0000 to 0x0_FFFF_FFFF. However, which peripheral interface handles these boot ROM accesses can be selected at power on.
As I said I could be reading this wrong. The 8548 cds code in 1.3 rc1 has:
#define CFG_BOOT_BLOCK 0xff000000 /* boot TLB block */ #define CFG_FLASH_BASE CFG_BOOT_BLOCK /* start of FLASH 16M */ #define CFG_FLASH_BANKS_LIST {0xff800000, CFG_FLASH_BASE}
Am I reading all this to mean I should load uboot to 0xff800000 - is that wrong ?
This means your Boot flash devices starts is at address 0xff800000, not that your boot code starts at this address.
For a start I would use the 8548 cds linker script unchanged, build your u-boot image, flash it to 0xfff80000 and single-step with your BDI.
Regards, Torsten