gdb.asciidoc

GDB Server

Packets

all packets: "$packet-data#checksum"

notification packets: "% data # checksum" ( Example : %Stop:…​)

empty response is "$#00"

testing

$ arm-none-eabi-gdb --nh --nx build/application.elf
(gdb) set debug remote 1
(gdb) target remote 192.168.42.1:54321
(gdb) i r

Thread id

id	Meaning
-1	all threads
0	any thread
1	first thread
p1.-1	all threads in process 1

Links

https://www.embecosm.com/appnotes/ean4/embecosm-howto-rsp-server-ean4-issue-2.html

https://ftp.gnu.org/old-gnu/Manuals/gdb/html_node/gdb_129.html

https://www.zeuthen.desy.de/dv/documentation/unixguide/infohtml/gdb/General-Query-Packets.html

https://ftp.gnu.org/old-gnu/Manuals/gdb/html_chapter/gdb_15.html

gdbserver protocol

https://sourceware.org/gdb/current/onlinedocs/gdb/Remote-Protocol.html

Black Magic Firmware

https://github.com/llvm/llvm-project/blob/master/lldb/docs/lldb-gdb-remote.txt

Dictionary

There are some GDB specific words used that only make sense in the GDB contet. These words are defined here.

Word	Meaning
stub	the JTAG/SWD probe
process	processes can have one or more threads. Each proces has a seperate memory and can not access the memory of another process.
thread	A code execution path. Threads can access the memory of other threads in the same process. (Embeedde context: in bare metal we have one thread per CPU core. If the firmware uses an OS then we can be "aware" of the threads of the OS.