arm926ejs target can not be halted

I’am working with an ARM926-ejs core and use openocd with a ft2232 linker.

Yesterday, I have my board work normally. But after burn the new bootloader into the flash, I’m not very sure about that if it was burned successfully. After it was burned, the board cannot work any more, cannot boot, and when I connect the core with jtag run “halt” command, it says that:

timed out while waiting for target halted
Runtime error, file “command.c”, line 469:

After some hours and made some change with the configuration file, the board was still down. Does anyone have some suggestion? And here is some of my configuration files:

telnet_port 3333
gdb_port 4444
jtag_khz 4
jtag_speed 0
jtag_nsrst_delay 200
jtag_ntrst_delay 200
arm7_9 fast_memory_access enable
interface ft2232
ft2232_vid_pid 0x1457 0x5118
ft2232_layout jtagkey
ft2232_device_desc “USB<=>JTAG&RS232”

ps: My openocd version is 0,2.0-in-development

thanks a lot