!
— extended mode-
Enable extended mode. In extended mode, the remote server is made
persistent. The R packet is used to restart the program being
debugged.
Reply:
- OK
- The remote target both supports and has enabled extended mode.
?
— last signal-
Indicate the reason the target halted. The reply is the same as for
step and continue.
Reply:
See Stop Reply Packets, for the reply specifications.
a
— reserved-
Reserved for future use.
A
arglen,
argnum,
arg,...
— set program arguments (reserved)-
Initialized argv[] array passed into program. arglen
specifies the number of bytes in the hex encoded byte stream arg.
See
gdbserver
for more details.
Reply:
- OK
- ENN
b
baud — set baud (deprecated)-
Change the serial line speed to baud.
JTC: When does the transport layer state change? When it's
received, or after the ACK is transmitted. In either case, there are
problems if the command or the acknowledgment packet is dropped.
Stan: If people really wanted to add something like this, and get
it working for the first time, they ought to modify ser-unix.c to send
some kind of out-of-band message to a specially-setup stub and have the
switch happen "in between" packets, so that from remote protocol's point
of view, nothing actually happened.
B
addr,mode — set breakpoint (deprecated)-
Set (mode is S) or clear (mode is C) a
breakpoint at addr. This has been replaced by the Z
and z packets.
c
addr — continue-
addr is address to resume. If addr is omitted, resume at
current address.
Reply:
See Stop Reply Packets, for the reply specifications.
C
sig;
addr — continue with signal-
Continue with signal sig (hex signal number). If
;
addr is omitted, resume at same address.
Reply:
See Stop Reply Packets, for the reply specifications.
d
— toggle debug (deprecated)-
Toggle debug flag.
D
— detach-
Detach GDB from the remote system. Sent to the remote target
before GDB disconnects.
Reply:
- no response
- GDB does not check for any response after sending this packet.
e
— reserved-
Reserved for future use.
E
— reserved-
Reserved for future use.
f
— reserved-
Reserved for future use.
F
— reserved-
Reserved for future use.
g
— read registers-
Read general registers.
Reply:
- XX...
- Each byte of register data is described by two hex digits. The bytes
with the register are transmitted in target byte order. The size of
each register and their position within the g packet are
determined by the GDB internal macros REGISTER_RAW_SIZE
and REGISTER_NAME macros. The specification of several standard
g
packets is specified below.
- ENN
- for an error.
G
XX... — write regs-
See read registers packet, for a description of the XX...
data.
Reply:
- OK
- for success
- ENN
- for an error
h
— reserved-
Reserved for future use.
H
ct... — set thread-
Set thread for subsequent operations (m, M, g,
G, et.al.). c depends on the operation to be performed: it
should be c for step and continue operations, g for other
operations. The thread designator t... may be -1, meaning all
the threads, a thread number, or zero which means pick any thread.
Reply:
- OK
- for success
- ENN
- for an error
i
addr,
nnn — cycle step (draft)-
Step the remote target by a single clock cycle. If
,
nnn is
present, cycle step nnn cycles. If addr is present, cycle
step starting at that address.
I
— signal then cycle step (reserved)-
See step with signal packet. See cycle step packet.
j
— reserved-
Reserved for future use.
J
— reserved-
Reserved for future use.
k
— kill request-
FIXME: There is no description of how to operate when a specific
thread context has been selected (i.e. does 'k' kill only that
thread?).
K
— reserved-
Reserved for future use.
l
— reserved-
Reserved for future use.
L
— reserved-
Reserved for future use.
m
addr,
length — read memory-
Read length bytes of memory starting at address addr.
Neither GDB nor the stub assume that sized memory transfers are
assumed using word alligned accesses. FIXME: A word aligned memory
transfer mechanism is needed.
Reply:
- XX...
- XX... is mem contents. Can be fewer bytes than requested if able
to read only part of the data. Neither GDB nor the stub assume
that sized memory transfers are assumed using word alligned
accesses. FIXME: A word aligned memory transfer mechanism is
needed.
- ENN
- NN is errno
M
addr,length:
XX... — write mem-
Write length bytes of memory starting at address addr.
XX... is the data.
Reply:
- OK
- for success
- ENN
- for an error (this includes the case where only part of the data was
written).
n
— reserved-
Reserved for future use.
N
— reserved-
Reserved for future use.
o
— reserved-
Reserved for future use.
O
— reserved-
Reserved for future use.
p
n... — read reg (reserved)-
See write register packet.
Reply:
- r....
- The hex encoded value of the register in target byte order.
P
n...=
r... — write register-
Write register n... with value r..., which contains two hex
digits for each byte in the register (target byte order).
Reply:
- OK
- for success
- ENN
- for an error
q
query — general query-
Request info about query. In general GDB queries have a
leading upper case letter. Custom vendor queries should use a company
prefix (in lower case) ex: qfsf.var. query may optionally
be followed by a , or ; separated list. Stubs must ensure
that they match the full query name.
Reply:
- XX...
- Hex encoded data from query. The reply can not be empty.
- ENN
- error reply
- Indicating an unrecognized query.
Q
var=
val — general set-
Set value of var to val.
See general query packet, for a discussion of naming conventions.
r
— reset (deprecated)-
Reset the entire system.
R
XX — remote restart-
Restart the program being debugged. XX, while needed, is ignored.
This packet is only available in extended mode.
Reply:
- no reply
- The R packet has no reply.
s
addr — step-
addr is address to resume. If addr is omitted, resume at
same address.
Reply:
See Stop Reply Packets, for the reply specifications.
S
sig;
addr — step with signal-
Like C but step not continue.
Reply:
See Stop Reply Packets, for the reply specifications.
t
addr:
PP,
MM — search-
Search backwards starting at address addr for a match with pattern
PP and mask MM. PP and MM are 4 bytes.
addr must be at least 3 digits.
T
XX — thread alive-
Find out if the thread XX is alive.
Reply:
- OK
- thread is still alive
- ENN
- thread is dead
u
— reserved-
Reserved for future use.
U
— reserved-
Reserved for future use.
v
— reserved-
Reserved for future use.
V
— reserved-
Reserved for future use.
w
— reserved-
Reserved for future use.
W
— reserved-
Reserved for future use.
x
— reserved-
Reserved for future use.
X
addr,
length:XX... — write mem (binary)-
addr is address, length is number of bytes, XX...
is binary data. The characters
$
, #
, and 0x7d
are
escaped using 0x7d
.
Reply:
- OK
- for success
- ENN
- for an error
y
— reserved-
Reserved for future use.
Y
reserved-
Reserved for future use.
z
t,
addr,
length — remove break or watchpoint (draft)-
See insert breakpoint or watchpoint packet.
Z
t,
addr,
length — insert break or watchpoint (draft)-
t is type: 0 - software breakpoint, 1 - hardware
breakpoint, 2 — write watchpoint, 3 - read watchpoint,
4 - access watchpoint; addr is address; length is in
bytes. For a software breakpoint, length specifies the size of
the instruction to be patched. For hardware breakpoints and watchpoints
length specifies the memory region to be monitored. To avoid
potential problems with duplicate packets, the operations should be
implemented in an idempotent way.
Reply:
- ENN
- for an error
- OK
- for success
- If not supported.