I want ntoarm-gdb to disassemble instruction at a given address in Thumb mode, but can’t get it to switch from ARM mode.
I found some solutions that worked for other versions of gdb (using pointer tagging and using word/halfword specifiers), but none of them seem to work in ntoarm-gdb:
code x/10i 0x78e6d001
0x78e6d001: mov.w r12, #0
0x78e6d005: str.w r12, [r5, #-8]
0x78e6d009: movw r3, #38900 ; 0x97f4
0x78e6d00d: movt r3, #31123 ; 0x7993
0x78e6d011: str r5, [r3, #0]
0x78e6d013: ldr.w r2, [r5, #-40]
0x78e6d017: ldr.w r1, [r2, #-24]
0x78e6d01b: mvn.w r12, #4
0x78e6d01f: str.w r12, [r5, #-20]
0x78e6d023: str.w r1, [r5, #-24][/code]
code x/10hi 0x78e6d000
0x78e6d000: stceq 0, cr15, [r0], {79} ; 0x4f
0x78e6d004: stcgt 8, cr15, [r8], {69} ; 0x45
0x78e6d008: mvnsvc pc, #-1879048188 ; 0x90000004
0x78e6d00c: orrsne pc, r3, #208666624 ; 0xc700000
0x78e6d010: ; instruction: 0xf855601d
0x78e6d014: ; instruction: 0xf8522c28
0x78e6d018: ; instruction: 0xf06f1c18
0x78e6d01c: ; instruction: 0xf8450c04
0x78e6d020: ; instruction: 0xf845cc14
0x78e6d024: ; instruction: 0x46741c18[/code]
Still parsing instructions in 4-bytes size
Any workarounds?
It’s important to note that gdb may figuure out the correct mode given symbols signifying a memory region as a .thumb_func, but unfortunately I have no symbols available.