Problem while doing SoCkit_SW_13.0 lab

I've downloaded the 'SoCKIT_Materials.zip' and do the involved labs: SoC_HW_Lab_13.0 and SoC_SW_Lab_13.0. I had problems when debugging the preloader in the SW lab:

when start debugging(click the debug button in DS-5), it first goto the reset instruction of the start.S file:

reset:

bl save_boot_params

, then jump to the save_boot_params function of the lowlevel_init.S file:

/* Save the parameter pass in by previous boot loader */

.global save_boot_params

save_boot_params:

# ifdef CONFIG_SPL_BUILD# if (CONFIG_PRELOADER_DEBUG_MEMORY_WRITE == 1)

/*

* write the debug memory header and value of R0 - R3 (which passed

* by BootROM) into debug memory region (which is on ocram)

*/

ldr r5, =CONFIG_PRELOADER_DEBUG_MEMORY_ADDR

ldr r4, =PRELOADER_DEBUG_MEMMORY_HEADER

stmia r5!, {r4}

stmia r5, {r0 -r3}

/* get the reset manager status register passed by BootROM */

add r5, r0,#0x34

ldr r4, =rst_mgr_status

ldr r5, [r5]

str r5, [r4]# endif /* CONFIG_PRELOADER_DEBUG_MEMORY_WRITE */

My first debug always halted at the 'ldr r5, [r5]' instruction. Then click the reset button(back to entry point) to do re-debug, and it can work correctly.

Any one knows why?

BTW, my quartus is version 13.1, and DS-5 is 5.15.0.