GDB-RSP-Researcher

Simple GDB-server for GDB RSP-protocol research.

Implemented:

• Connection to GDB-client by TCP
• Responses to RSP commands from GDB-client
• Loop imitation of target program. And interrupt it by ^C (working in two threads)

Build and launch

cargo run --release -- --loop
or
cargo run --release

Launch

gdb-rsp-researcher.exe --loop
or
gdb-rsp-researcher.exe

Arguments

--loop or -l : Loop imitation of target program execution (optional)

Working with GDB-client

Launch GDB-client with path to elf-file as parameter:

/path-to-gdb/gdb /path-to-elf/file.elf

In GDB CLI:

Turn on RSP debug mode (optional):

(gdb) set debug remote 1

Connect to GDB-server:

(gdb) target remote localhost:9999
    ...
    initial dialog without loading elf sections

Halt the core:

(gdb) monitor reset halt
    or
(gdb) monitor reset init

Load sections from elf:

(gdb) load /path-to-elf/file.elf
    or
(gdb) load

It is ready for work

Set breakpoint:

(gdb) break function_name
    or
(gdb) b function_name
    or
(gdb) b linenum
    or
(gdb) b filename:linenum
    or
(gdb) b 0xaddress

Set watchpoint:

(gdb) watch var

Information about breakpoints and watchpoints:

(gdb) info break

Launch execution:

(gdb) continue
    or
(gdb) c

Interrupt execution: Ctrl+C

Execute one line:

(gdb) step
    or
(gdb) s

Execute one instruction:

(gdb) stepi
    or
(gdb) si

Examining memory:

(gdb) x addr
(gdb) x var
(gdb) print/x var
(gdb) x/8b 0x10030000 – read 8 bytes from address
(gdb) x/8c 0x10030000 - 8 chars
(gdb) x/8h 0x10030000 – 8 half-words (2 bytes)
(gdb) x/8w 0x10030000 – 8 words (4 bytes)

Write register:

(gdb) set $t0 = main
    or
(gdb) set $t0 = 0xaddress

Read register:

(gdb) print $t0
    or
(gdb) p/x $t0

Read all registers:

(gdb) info registers
    or
(gdb) info all-registers