[ECOS] Question about hal stub debugging support. Thanks a lot.

[<jameshq at liverpool dot ac dot uk>]

Hi all:
   I am trying to adding debugging support for a new target, I come
across some question. I hope somebody can give me idea. thanks a lot.
In file "arm_stub.c"  function "__single_step()"

// Decode instruction to decide what the next PC will be
ss_saved_pc = (unsigned long) target_ins((unsigned long*)pc, curins);

why does here need to call "target_ins()" for decoding next
instruction? Isn't that just the next instruction follows the current
one? (what's for decoding?) 
for example:

Instruction #1:     mov r0,#10 
Instruction #2:     mov r1,r0

if currently breakpointed at instruction #1 and next instruction is
#2, so why does "target_ins()" called for decoding the next
instruction, (isn't that just "mov r1,r0" ? can't we just return
this?)

I may misunderstand this, hope anybody can help me out. Thanks a lot

qiang

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