[U-Boot-Users] Help--750FX, Cannot handle DEC or External Interrupt exception.U-Boot-1.1.1, ELDK3.0,RedHat

高海 g_hai at huawei.com
Thu Aug 26 09:28:01 CEST 2004


My target platform is with 750FX and MPC107, 256M ram, a NS16c552 serial and also a Intel 82559 compatiable ethernet controller.

I can get Program Exeption(0x700) printing msg when I "go" a program from an arbitary address within U-Boot's shell.
But when I set EE bit in MSR register, U-Boot seems to hang there, nothing 
output.

I guess the exception handling have problem. But I really didn't change any codes in Start.s or ppc_asm.tmpl.

Additonal, when I write a dword to a address outside my BAT-Array covered range, DSI Exception(0x300) also seems hanging, nothing output. I originally image that the UnknownException() funciton can print something on my console.

In any case Program Exception handling does work. And it seems when I set IP bit in MSR register, the higher Exception handler which is borned in flash can go up to the address { hdlr - _start + EXC_OFF_SYS_RESET; (refer to ppc_asm.tmpl Line 304) }. There is a number such as 0x3688. Maybe CPU turned to that address to fetch next instruction. Unfortunately, that address is dull, so program exception occured. And then I got something on the console just like that after I "go 0x3688".



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