Other Parts Discussed in Thread: SYSBIOS
Hello forum,
my application ends in an endless loop inside the exception handler (Hwi_asm.sv7M). The Watchdog is enabled, but does not restart the application. When WDT_VALUE reaches zero this register is reloaded with the value stored in the WDT_LOAD register. Here is the code of the exeption handler:
ti_sysbios_family_arm_m3_Hwi_excHandlerAsm__I:
.asmfunc
tst lr, #4 ; context on PSP?
ite NE
mrsne r0, psp ; if yes, then use PSP
moveq r0, sp ; else use MSP
mov sp, r0 ; use this stack
stmfd sp!, {r4-r11} ; save r4-r11 while we're at it
mov r0, sp ; pass sp to exception handler
mov r1, lr ; pass lr too
mov r4, lr ; preserve LR in r4
ldr r2, excHandlerAddr
blx r2
mov r0, sp ; for ROV
mov r1, r4 ; for ROV
$1
b $1 ; spin here indefinitely
My questions:
How can I find out, which exception has happened?
Can the RTOS Object View tell me that?
Why doesn't the Watchdog cause a restart?
The loop in the disassembly:
309 tst lr, #4 ; context on PSP?
ti_sysbios_family_arm_m3_Hwi_excHandlerAsm__I():
0005ad50: F01E0F04 tst.w r14, #4
310 ite NE
0005ad54: BF14 ite ne
311 mrsne r0, psp ; if yes, then use PSP
0005ad56: F3EF8009 mrsne r0, psp
312 moveq r0, sp ; else use MSP
0005ad5a: 4668 moveq r0, r13
314 mov sp, r0 ; use this stack
0005ad5c: 4685 mov r13, r0
315 stmfd sp!, {r4-r11} ; save r4-r11 while we're at it
0005ad5e: E92D0FF0 push.w {r4, r5, r6, r7, r8, r9, r10, r11}
316 mov r0, sp ; pass sp to exception handler
0005ad62: 4668 mov r0, r13
317 mov r1, lr ; pass lr too
0005ad64: 4671 mov r1, r14
318 mov r4, lr ; preserve LR in r4
0005ad66: 4674 mov r4, r14
320 ldr r2, excHandlerAddr
0005ad68: 4A02 ldr r2, [pc, #8]
321 blx r2
0005ad6a: 4790 blx r2
323 mov r0, sp ; for ROV
0005ad6c: 4668 mov r0, r13
324 mov r1, r4 ; for ROV
0005ad6e: 4621 mov r1, r4
326 b $1 ; spin here indefinitely
$1_$6:
0005ad70: E7FE b $1_$6
The content of the stackpointer is 0x20000B48, here is the region (0x20000B18 to 0x20000BA8) of the memory browser:
BEBEBEBE BEBEBEBE BEBEBEBE BEBEBEBE BEBEBEBE BEBEBEBE BEBEBEBE BEBEBEBE BEBEBEBE BEBEBEBE FFFFFFFD 0005AD6D
FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF 00000000 00000000 0000EB49 00000002
2002FFF0 00045D51 0000EB4E 41000000 FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF
FFFFFFFF
The content of 0x20000B48 (italic and bold) is 0xFFFFFFFF.
But the value at the address 0x20000B40 (italic) is 0xFFFFFFFD, the content of register R4.
And the content at address 0x20000B44 (bold) is 0x0005AD6D.
The content of LR is also 0x0005AD6D.
Can anybody halp me?
I will have a closer look in the assembly code to find out more.
Thanks in advance.
BR Guenther
