Debugging a ASM Program with spike

Interactive Debugging Mode

Let us debug example.elf present inside spiking folder.

cd $HOME

cd spiking

make command is used to generate the executables for all the C and Assembly Programs hosted inside the spiking folder,

make

To invoke interactive debug mode, launch spike with -d:

$(which spike) -d $(which pk) example.elf

Note : Press Enter key, to advance by one instruction.

Commands

To see the contents of an integer register (0 is for core 0):

: reg 0 a0

To see the contents of a floating point register as Single precision:

: fregs 0 ft0

To see the contents of a floating point register as Double precision:

: fregd 0 ft0

To see the contents of a memory location (physical address in hex):

: mem 2020

To see the contents of memory with a virtual address (0 for core 0):

: mem 0 2020

You can execute till the desired instruction using the UNTIL command:

: until pc 0 10010004

Note: Use objdump to find the address of the required instruction

Debugging

: mem 1000
0x0202859300000297
:
core   0: 0x0000000000001000 (0x00000297) auipc   t0, 0x0
:
core   0: 0x0000000000001004 (0x02028593) addi    a1, t0, 32
: until pc 0 10010004
:
core   0: 0x0000000010010004 (0x40105613) srai    a2, zero, 1
:
core   0: 0x0000000010010008 (0x40105513) srai    a0, zero, 1
:
core   0: 0x000000001001000c (0x40105793) srai    a5, zero, 1
:
core   0: 0x0000000010010010 (0x40105313) srai    t1, zero, 1
:
core   0: 0x0000000010010014 (0x00000505) c.addi  a0, 1
:
core   0: 0x0000000010010016 (0x00d50613) addi    a2, a0, 13
:
core   0: 0x000000001001001a (0x04050893) addi    a7, a0, 64
:
core   0: 0x000000001001001e (0x00000797) auipc   a5, 0x0
: reg 0 a0
0x0000000000000001
: reg 0 a2
0x000000000000000e
: reg 0 a7
0x0000000000000041
: fregs 0 ft0
0x0000000000000000

At any point during execution (even without -d), you can enter the interactive debug mode with <control>-<c>.

To end the simulation from the debug prompt, press <control>-<c> or

: q