##Debug Assembly with GDB for ARMv8 on QEMU
###build from source code
assume you have installed QEMU, cross-compiler include cross-platform GDB
ARMv8 source code:
test.S
.globl _start
_start:
mov x0, #0
mov x1, #1
mov x2, #2
loop:
b loop
-
compile:
aarch64-linux-gnu-as -o test.o test.S -
link:
aarch64-linux-gnu-ld -o test test.o -o test test.o -
objdump (optional):
aarch64-linux-gnu-objdump -d test -
start gdb server: (use port 11111 and run in deamon)
qemu-aarch64 -g 11111 test & -
start gdb: (specified the execute file)
aarch64-linux-gnu-gdb test
###GDB commands
(gdb) target remote localhost:11111 #connect from localhost:11111
(gdb) disassemble #show the disassemble
(gdb) display /10i $pc-16 #show 10 instruction near the PC register
(gdb) x /16 0x400000 #show 16 word on memory 0x400000
(gdb) b *0x400080 #add a breakpoint with address
(gdb) ni #next instruction
(gdb) si #step instruction
(gdb) c #continue exec until breakpoint
(gdb) info register #show register
(gdb) display /x $x0 #display x0 register