Kernel debugging on 460EX

Hi,

I'm trying to debug Linux kernel (2.6.26) on custom 460EX based board using BDI3000. The U-Boot succeeds to download kernel and DTB into RAM and jump to kernel code. Immediately after that the board resets without printing anything to console. I'm trying to set a breakpoint at _start kernel routine, but it doesn't work.

My BDI3000 configuration file looks like this:

[INIT]

[TARGET]

JTAGCLOCK       4       ;use 5 MHz JTAG clock
CPUTYPE         440     ;the used target CPU type
WAKEUP          500     ;wakeup time after reset
BREAKMODE       SOFT    ;SOFT or HARD, HARD uses PPC hardware breakpoint
STEPMODE        HWBP    ;JTAG or HWBP, HWBP uses one or two hardware breakpoints
RESET           HARD
MMU             XLAT

In BDI I let u-boot complete the initialization and get to the prompt. Then I do

halt
bi 0xc0000000
go

and run bootd command in u-boot. However the board resets without breaking into kernel code. What am I doing wrong ?

Thanks a lot in advance !

Felix.