Microcontroller Board Support Package http://mbsp/ 2026-04-21T14:41:30+00:00 http://mbsp/ http://mbsp/_media/logo.png text/html 2026-03-02T22:58:41+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:arm_cortex_m?rev=1772492321&do=diff ARM Cortex-M Architecture processor Armv6-M Cortex-M0, Cortex-M0+, Cortex-M1 Armv7-M Cortex-M3, Cortex-M4, Cortex-M7 Armv8-M Cortex-M23, Cortex-M33 Cortex-M0+ text/html 2026-03-02T23:15:02+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_bc?rev=1772493302&do=diff command bc Format: ‘bc’ Meaning: Backward continue. Execute the target system in reverse. No parameter. text/html 2026-03-02T23:15:38+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_bs?rev=1772493338&do=diff command bs Format: ‘bs’ Meaning: Backward single step. Execute one instruction in reverse. No parameter. text/html 2026-03-02T23:11:36+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_exclamation_mark?rev=1772493096&do=diff command ! Format: ‘!’ Meaning: 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 Example: $!#00 text/html 2026-03-02T23:32:59+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lcq_p?rev=1772494379&do=diff command qP Format: ‘qP mode thread-id’ Meaning: Returns information on thread-id. Where: mode is a hex encoded 32 bit mode; thread-id is a thread ID (see thread-id syntax). Don’t use this packet; use the ‘qThreadExtraInfo’ query instead. text/html 2026-03-02T23:13:58+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_b?rev=1772493238&do=diff command b Format: ‘b baud’ Meaning: (Don’t use this packet; its behavior is not well-defined.) 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. text/html 2026-03-02T23:16:23+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_c?rev=1772493383&do=diff command c Format: ‘c [addr]’ Meaning: Continue at addr, which is the address to resume. If addr is omitted, resume at current address. This packet is deprecated for multi-threading support. Use vCont command. text/html 2026-03-02T23:17:23+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_d?rev=1772493443&do=diff command d Format: ‘d’ Meaning: Toggle debug flag. Don’t use this packet! text/html 2026-03-02T23:19:00+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_g?rev=1772493540&do=diff command g Format: ‘g’ Meaning: 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 target description (see Target Descriptions); in the absence of a target description, this is done using code internal to GDB; typically this is some customary register layout for the architecture in question.… text/html 2026-03-02T23:20:30+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_i?rev=1772493630&do=diff command i Format: ‘i [addr[,nnn]]’ Meaning: 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. text/html 2026-03-02T23:21:28+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_k?rev=1772493688&do=diff command k Format: ‘k’ Meaning: Kill request. The exact effect of this packet is not specified. For a bare-metal target, it may power cycle or reset the target system. For that reason, the ‘k’ packet has no reply. For a single-process target, it may kill that process if possible. text/html 2026-03-02T23:21:55+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_m?rev=1772493715&do=diff command m Format: ‘m addr,length’ Meaning: Read length addressable memory units starting at address addr. Note that addr does not have to be aligned to any particular boundary. The stub need not use any particular size or alignment when gathering data from memory for the response; even if addr is word-aligned and length is a multiple of the word size, the stub is free to use byte accesses, or not. For this reason, this packet may not be suitable for accessing memory-mapped I/O devices. text/html 2026-03-02T23:22:46+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_p?rev=1772493766&do=diff command p Format: ‘p n’ Meaning: Read the value of register n; n is in hex. Reply: ‘XX…’ the register’s value, two hex digits for each byte in the register (target byte order). text/html 2026-03-02T23:39:46+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_attached?rev=1772494786&do=diff command qAttached Format: ‘qAttached[:pid]’ Meaning: Return an indication of whether the remote server attached to an existing process or created a new process. When the multiprocess protocol extensions are supported, pid is an integer in hexadecimal format identifying the target process. Otherwise, GDB will omit the pid field and the query packet will be simplified as ‘qAttached’. text/html 2026-03-02T23:24:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_c?rev=1772493880&do=diff command qC Format: ‘qC’ Meaning: Return the current thread ID. A thread ID is normally a positive number with a target-specific interpretation, formatted as big-endian hex strings. A thread-id can also be a literal ‘-1’ to indicate all threads, or ‘0’ to pick any thread. text/html 2026-03-02T23:25:19+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_crc?rev=1772493919&do=diff command qCRC Format: ‘qCRC:addr,length’ Meaning: Compute the CRC checksum of a block of memory using CRC-32 defined in IEEE 802.3. The CRC is computed one byte at a time, taking the most significant bit of each byte first. The initial pattern code 0xffffffff is used to ensure leading zeros affect the CRC. text/html 2026-03-02T23:28:37+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_fthreadinfo?rev=1772494117&do=diff command qfThreadInfo Format: ‘qfThreadInfo’ Meaning: Obtain a list of all active thread IDs from the target (OS). Since there may be too many active threads to fit into one reply packet, this query works iteratively: it may require more than one query/reply sequence to obtain the entire list of threads. The first query of the sequence will be the ‘qfThreadInfo’ query; subsequent queries in the sequence will be the ‘qsThreadInfo’ query. text/html 2026-03-02T23:30:23+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_gettibaddr?rev=1772494223&do=diff command qGetTIBAddr Format: ‘qGetTIBAddr:thread-id’ Meaning: Fetch address of the Windows OS specific Thread Information Block. thread-id is the thread ID associated with the thread. Reply: XX… Hex encoded (big endian) bytes representing the linear address of the thread information block. text/html 2026-03-02T23:29:57+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_gettlsaddr?rev=1772494197&do=diff command qGetTLSAddr Format: ‘qGetTLSAddr:thread-id,offset,lm’ Meaning: Fetch the address associated with thread local storage specified by thread-id, offset, and lm. thread-id is the thread ID associated with the thread for which to fetch the TLS address. See thread-id syntax. text/html 2026-03-02T23:31:30+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_isaddresstagged?rev=1772494290&do=diff command qIsAddressTagged Format: ‘qIsAddressTagged:address’ Meaning: Check if address address is in a memory tagged region; if it is, it’s said to be tagged. The target is responsible for checking it, as this is architecture-specific. address is the address to be checked. text/html 2026-03-02T23:30:47+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_l?rev=1772494247&do=diff command qL Format: ‘qL startflag threadcount nextthread’ Meaning: Obtain thread information from RTOS. Where: startflag (one hex digit) is one to indicate the first query and zero to indicate a subsequent query; threadcount (two hex digits) is the maximum number of threads the response packet can contain; and nextthread (eight hex digits), for subsequent queries (startflag is zero), is returned in the response as argthread. text/html 2026-03-02T23:31:09+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_memtags?rev=1772494269&do=diff command qMemTags Format: ‘qMemTags:start address,length:type’ Meaning: Fetch memory tags of type type from the address range [start address, start address + length). The target is responsible for calculating how many tags will be returned, as this is architecture-specific. text/html 2026-03-02T23:32:31+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_offsets?rev=1772494351&do=diff command qOffsets Format: ‘qOffsets’ Meaning: Get section offsets that the target used when relocating the downloaded image. Reply: Text=xxx;Data=yyy[;Bss=zzz] Relocate the Text section by xxx from its original address. Relocate the Data section by yyy from its original address. If the object file format provides segment information (e.g. ELF ‘PT_LOAD’ program headers), GDB will relocate entire segments by the supplied offsets. text/html 2026-03-02T23:36:20+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_rcmd?rev=1772494580&do=diff command qRcmd Format: ‘qRcmd,command’ Meaning: command (hex encoded) is passed to the local interpreter for execution. Invalid commands should be reported using the output string. Before the final result packet, the target may also respond with a number of intermediate ‘Ooutput’ console output packets. Implementors should note that providing access to a stubs’s interpreter may have security implications. text/html 2026-03-02T23:36:41+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_search?rev=1772494601&do=diff command qSearch Format: ‘qSearch:memory:address;length;search-pattern’ Meaning: Search length bytes at address for search-pattern. Both address and length are encoded in hex; search-pattern is a sequence of bytes, also hex encoded. Reply: 0 text/html 2026-03-02T23:29:24+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_sthreadinfo?rev=1772494164&do=diff command qsThreadInfo Format: ‘qsThreadInfo’ Meaning: Obtain a list of all active thread IDs from the target (OS). Since there may be too many active threads to fit into one reply packet, this query works iteratively: it may require more than one query/reply sequence to obtain the entire list of threads. The first query of the sequence will be the ‘qfThreadInfo’ query; subsequent queries in the sequence will be the ‘qsThreadInfo’ query. text/html 2026-03-02T23:37:37+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_supported?rev=1772494657&do=diff command qSupported Format: ‘qSupported [:gdbfeature [;gdbfeature]… ]’ Meaning: Tell the remote stub about features supported by GDB, and query the stub for features it supports. This packet allows GDB and the remote stub to take advantage of each others’ features. ‘qSupported’ also consolidates multiple feature probes at startup, to improve GDB performance—a single larger packet performs better than multiple smaller probe packets on high-latency links. Some features may enable behavior which m… text/html 2026-03-02T23:38:06+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_symbol?rev=1772494686&do=diff command qSymbol Format: ‘qSymbol::’ or ‘qSymbol:sym_value:sym_name’ Meaning: (qSymbol::) Notify the target that GDB is prepared to serve symbol lookup requests. Accept requests from the target for the values of symbols. (qSymbol:sym_value:sym_name) Set the value of sym_name to sym_value. text/html 2026-03-02T23:38:50+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_threadextrainfo?rev=1772494730&do=diff command qThreadExtraInfo Format: ‘qThreadExtraInfo,thread-id’ Meaning: Obtain from the target OS a printable string description of thread attributes for the thread thread-id. This string may contain anything that the target OS thinks is interesting for GDB to tell the user about the thread. The string is displayed in GDB’s info threads display. Some examples of possible thread extra info strings are ‘Runnable’, or ‘Blocked on Mutex’. (Note that the qThreadExtraInfo packet’s name is separated … text/html 2026-03-02T23:39:18+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_q_xfer?rev=1772494758&do=diff command qXfer Format: ‘qXfer:object:read:annex:offset,length’ or ‘qXfer:object:write:annex:offset:data…’ or ‘qXfer:object:operation:…’ Meaning: (‘qXfer:object:read:annex:offset,length’) Read uninterpreted bytes from the target’s special data area identified by the keyword object. Request length bytes starting at offset bytes into the data. The content and encoding of annex is specific to object; it can supply additional details about what data to access. text/html 2026-03-02T23:41:05+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_r?rev=1772494865&do=diff command r Format: ‘r’ Meaning: Reset the entire system. Don’t use this packet; use the ‘R’ packet instead. text/html 2026-03-02T23:42:02+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_s?rev=1772494922&do=diff command s Format: ‘s [addr]’ Meaning: Single step, resuming at addr. If addr is omitted, resume at same address. This packet is deprecated for multi-threading support. See vCont packet. text/html 2026-03-02T23:42:51+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_t?rev=1772494971&do=diff command t Format: ‘t addr:PP,MM’ Meaning: Search backwards starting at address addr for a match with pattern PP and mask MM, both of which are are 4 byte long. There must be at least 3 digits in addr. text/html 2026-03-02T23:49:15+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_x?rev=1772495355&do=diff command x Format: ‘x addr,length’ Meaning: Read length addressable memory units starting at address addr. Note that addr does not have to be aligned to any particular boundary. The stub need not use any particular size or alignment when gathering data from memory for the response; even if addr is word-aligned and length is a multiple of the word size, the stub is free to use byte accesses, or not. For this reason, this packet may not be suitable for accessing memory-mapped I/O devices. text/html 2026-03-02T23:49:57+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_lc_z?rev=1772495397&do=diff command z Meaning: Remove a type breakpoint or watchpoint starting at address 'address' of kind 'kind'. Implementation notes: A remote target shall return an empty string for an unrecognized breakpoint or watchpoint packet type. A remote target shall support either both or neither of a given ‘Ztype…’ and ‘ztype…’ packet pair. To avoid potential problems with duplicate packets, the operations should be implemented in an idempotent way. text/html 2026-03-02T23:13:02+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_question_mark?rev=1772493182&do=diff command ? Format: ‘?’ Meaning: query the reason for target halt. TODO Reply: TODO Example: $?#00 text/html 2026-03-02T23:32:07+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_ucq_memtags?rev=1772494327&do=diff command QMemTags Format: ‘QMemTags:start address,length:type:tag bytes’ Meaning: Store memory tags of type type to the address range [start address, start address + length). The target is responsible for interpreting the type, the tag bytes and modifying the memory tag granules accordingly, given this is architecture-specific. text/html 2026-03-02T23:13:29+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_a?rev=1772493209&do=diff command A Format: ‘A arglen,argnum,arg,…’ Meaning: 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 text/html 2026-03-02T23:14:31+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_b?rev=1772493271&do=diff command B Format: ‘B addr,mode’ Meaning: Set (mode is ‘S’) or clear (mode is ‘C’) a breakpoint at addr. Don’t use this packet. Use the ‘Z’ and ‘z’ packets instead. text/html 2026-03-02T23:16:54+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_c?rev=1772493414&do=diff command C Format: ‘C sig[;addr]’ Meaning: Continue with signal sig (hex signal number). If ‘;addr’ is omitted, resume at same address. This packet is deprecated for multi-threading support. Use vCont command. text/html 2026-03-02T23:18:01+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_d?rev=1772493481&do=diff command D Format: ‘D[;pid]’ Meaning: Without pid this detaches from the target MCU. With pid given (multiprocess protocol extension) it detaches from the given process. pid is a big-endian hex string. Reply: OK text/html 2026-03-02T23:18:30+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_f?rev=1772493510&do=diff command F Format: ‘F RC,EE,CF;XX’ Meaning: A reply from GDB to an ‘F’ packet sent by the target. This is part of the File-I/O protocol extension. text/html 2026-03-02T23:19:28+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_g?rev=1772493568&do=diff command G Format: ‘G XX…’ Meaning: Write general registers. Each byte of register data is described by two hex digits. The bytes with the register are transmitted in target byte order. Reply: OK text/html 2026-03-02T23:19:57+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_h?rev=1772493597&do=diff command H Format: ‘H op thread-id’ Meaning: Set thread for subsequent operations (‘m’, ‘M’, ‘g’, ‘G’, et.al.). Depending on the operation to be performed, op should be ‘c’ for step and continue operations (note that this is deprecated, supporting the ‘vCont’ command is a better option), and ‘g’ for other operations. text/html 2026-03-02T23:21:03+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_i?rev=1772493663&do=diff command ! Format: ‘I’ Meaning: Signal, then cycle step. text/html 2026-03-02T23:22:18+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_m?rev=1772493738&do=diff command M Format: ‘M addr,length:XX…’ Meaning: Write length addressable memory units starting at address addr. The data is given by XX…; each byte is transmitted as a two-digit hexadecimal number. Reply: OK All the data was written successfully. (If only part of the data was written, this command returns an error.) text/html 2026-03-02T23:23:13+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_p?rev=1772493793&do=diff command P Format: ‘P n…=r…’ Meaning: Write register n… with value r…. The register number n is in hexadecimal, and r… contains two hex digits for each byte in the register (target byte order). Reply: OK text/html 2026-03-02T23:23:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_agent?rev=1772493820&do=diff command QAgent Format: ‘QAgent:x’ Meaning: Turn on or off the agent as a helper to perform some debugging operations delegated from GDB Example: $QAgent:1#00 turn control agent on $QAgent:0#00 turn control agent off text/html 2026-03-02T23:24:10+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_allow?rev=1772493850&do=diff command QAllow Format: ‘QAllow:op:val…’ Meaning: Specify which operations GDB expects to request of the target, as a semicolon-separated list of operation name and value pairs. Possible values for op include ‘WriteReg’, ‘WriteMem’, ‘InsertBreak’, ‘InsertTrace’, ‘InsertFastTrace’, and ‘Stop’. val is either 0, indicating that GDB will not request the operation, or 1, indicating that it may. (The target can then use this to set up its own internals optimally, for instance if the debugger never ex… text/html 2026-03-02T23:40:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_btrace?rev=1772494817&do=diff command Qbtrace Format: ‘Qbtrace:bts’ or ‘Qbtrace:pt’ or ‘Qbtrace:off’ Meaning: bts: Enable branch tracing for the current thread using Branch Trace Store. pt: Enable branch tracing for the current thread using Intel Processor Trace. text/html 2026-03-02T23:40:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_btrace_conf?rev=1772494840&do=diff command Qbtrace-conf Format: ‘Qbtrace-conf:bts:size=value’ or ‘Qbtrace-conf:pt:size=value’ or ‘Qbtrace-conf:pt:ptwrite=(yes|no)’ or ‘Qbtrace-conf:pt:event-tracing=(yes|no)’ Meaning: (‘Qbtrace-conf:bts:size=value’) Set the requested ring buffer size for new threads that use the btrace recording method in bts format. text/html 2026-03-02T23:33:55+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_catchsyscalls?rev=1772494435&do=diff command QCatchSyscalls Format: ‘QCatchSyscalls:1 [;sysno]…’ ‘QCatchSyscalls:0’ Meaning: Enable (‘QCatchSyscalls:1’) or disable (‘QCatchSyscalls:0’) catching syscalls from the inferior process. For ‘QCatchSyscalls:1’, each listed syscall sysno (encoded in hex) should be reported to GDB. If no syscall sysno is listed, every system call should be reported. text/html 2026-03-02T23:25:55+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_disablerandomization?rev=1772493955&do=diff command QDisableRandomization Format: ‘QDisableRandomization:value’ Meaning: Some target operating systems will randomize the virtual address space of the inferior process as a security feature, but provide a feature to disable such randomization, e.g. to allow for a more deterministic debugging experience. On such systems, this packet with a value of 1 directs the target to disable address space randomization for processes subsequently started via ‘vRun’ packets, while a packet with a value o… text/html 2026-03-02T23:27:42+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_environemnetreset?rev=1772494062&do=diff command QEnvironmentReset Format: ‘QEnvironmentReset’ Meaning: On UNIX-like targets, this packet is used to reset the state of environment variables in the remote target before starting the inferior. In this context, reset means unsetting all environment variables that were previously set by the user (i.e., were not initially present in the environment). It is sent to gdbserver before the ‘QEnvironmentHexEncoded’ and the ‘QEnvironmentUnset’ commands. text/html 2026-03-02T23:26:51+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_environmenthexencoded?rev=1772494011&do=diff command QEnvironmentHexEncoded Format: ‘QEnvironmentHexEncoded:hex-value’ Meaning: On UNIX-like targets, it is possible to set environment variables that will be passed to the inferior during the startup process. This packet is used to inform gdbserver of an environment variable that has been defined by the user on GDB. text/html 2026-03-02T23:27:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_environmentunset?rev=1772494037&do=diff command QEnvironmentUnset Format: ‘QEnvironmentUnset:hex-value’ Meaning: On UNIX-like targets, it is possible to unset environment variables before starting the inferior in the remote target. This packet is used to inform gdbserver of an environment variable that has been unset by the user on GDB. text/html 2026-03-02T23:33:29+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_nonstop?rev=1772494409&do=diff command QNonStop Format: ‘QNonStop:x’ Meaning: Enter non-stop (‘QNonStop:1’) or all-stop (‘QNonStop:0’) mode. This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response. text/html 2026-03-02T23:34:35+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_passsignals?rev=1772494475&do=diff command QPassSignals Format: ‘QPassSignals: signal [;signal]…’ Meaning: Each listed signal should be passed directly to the inferior process. Signals are numbered identically to continue packets and stop replies. Each signal list item should be strictly greater than the previous item. These signals do not need to stop the inferior, or be reported to GDB. All other signals should be reported to GDB. Multiple ‘QPassSignals’ packets do not combine; any earlier ‘QPassSignals’ list is completely re… text/html 2026-03-02T23:35:01+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_programsignals?rev=1772494501&do=diff command QProgramSignals Format: ‘QProgramSignals: signal [;signal]…’ Meaning: Each listed signal may be delivered to the inferior process. Others should be silently discarded. In some cases, the remote stub may need to decide whether to deliver a signal to the program or not without GDB involvement. One example of that is while detaching — the program’s threads may have stopped for signals that haven’t yet had a chance of being reported to GDB, and so the remote stub can use the signal list s… text/html 2026-03-02T23:28:08+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_setworkingdirectory?rev=1772494088&do=diff command QSetWorkingDir Format: ‘QSetWorkingDir:[directory]’ Meaning: This packet is used to inform the remote server of the intended current working directory for programs that are going to be executed. The packet is composed by directory, an hex encoded representation of the directory that the remote inferior will use as its current working directory. If directory is an empty string, the remote server should reset the inferior’s current working directory to its original, empty value. text/html 2026-03-02T23:37:12+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_startnoackmode?rev=1772494632&do=diff command QStartNoAckMode Format: ‘QStartNoAckMode’ Meaning: Request that the remote stub disable the normal ‘+’/‘-’ protocol acknowledgments. GDB acknowledges this response, but neither the stub nor GDB shall send or expect further ‘+’/‘-’ acknowledgments in the current connection. text/html 2026-03-02T23:26:21+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_startupwithshell?rev=1772493981&do=diff command QStartupWithShell Format: ‘QStartupWithShell:value’ Meaning: On UNIX-like targets, it is possible to start the inferior using a shell program. This is the default behavior on both GDB and gdbserver (see set startup-with-shell). This packet is used to inform gdbserver whether it should start the inferior using a shell or not. text/html 2026-03-02T23:35:26+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_threadevents?rev=1772494526&do=diff command QThreadEvents Format: ‘QThreadEvents:x’ Meaning: Enable (‘QThreadEvents:1’) or disable (‘QThreadEvents:0’) reporting of thread create and exit events. See thread create event, for the reply specifications. For example, this is used in non-stop mode when GDB stops a set of threads and synchronously waits for the their corresponding stop replies. Without exit events, if one of the threads exits, GDB would hang forever not knowing that it should no longer expect a stop for that same threa… text/html 2026-03-02T23:35:55+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_q_threadoptions?rev=1772494555&do=diff command QThreadOptions Format: ‘QThreadOptions[;options[:thread-id]]…’ Meaning: For each inferior thread, the last options in the list with a matching thread-id are applied. Any options previously set on a thread are discarded and replaced by the new options specified. Threads that do not match any thread-id retain their previously-set options. If multiprocess extensions are supported, options can be specified to apply to all threads of a process by using the ‘ppid.-1’ form of thread-id. Opti… text/html 2026-03-02T23:41:30+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_r?rev=1772494890&do=diff command R Format: ‘R XX’ Meaning: Restart the program being debugged. The XX, while needed, is ignored. This packet is only available in extended mode. Reply: no reply. text/html 2026-03-02T23:42:26+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_s?rev=1772494946&do=diff command S Format: ‘S sig[;addr]’ Meaning: Step with signal. This is analogous to the ‘C’ command, but requests a single-step, rather than a normal resumption of execution. This command is deprecated for multi-threading support. Use vCont command. text/html 2026-03-02T23:43:19+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_t?rev=1772494999&do=diff command T Format: ‘T thread-id’ Meaning: Find out if the thread thread-id is alive. Reply: OK if thread is still alive. text/html 2026-03-02T23:49:36+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_x?rev=1772495376&do=diff command X Format: ‘X addr,length:XX…’ Meaning: Write data to memory, where the data is transmitted in binary. Memory is specified by its address addr and number of addressable memory units length; ‘XX…’ is binary data. Reply: OK text/html 2026-03-02T23:50:24+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_uc_z?rev=1772495424&do=diff command Z Meaning: Insert a type breakpoint or watchpoint starting at address 'address' of kind 'kind'. Implementation notes: A remote target shall return an empty string for an unrecognized breakpoint or watchpoint packet type. A remote target shall support either both or neither of a given ‘Ztype…’ and ‘ztype…’ packet pair. To avoid potential problems with duplicate packets, the operations should be implemented in an idempotent way. text/html 2026-03-02T23:43:43+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_vattach?rev=1772495023&do=diff command vAttach Format: ‘vAttach;pid’ Meaning: Attach to a new process with the specified process ID pid. The process ID is a hexadecimal integer identifying the process. In all-stop mode, all threads in the attached process are stopped; in non-stop mode, it may be attached without being stopped if that is supported by the target. text/html 2026-03-02T23:44:06+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_vcont?rev=1772495046&do=diff command vCont Format: ‘vCont[;action[:thread-id]]…’ Meaning: Resume the inferior, specifying different actions for each thread. For each inferior thread, the leftmost action with a matching thread-id is applied. Threads that don’t match any action remain in their current state. Thread IDs are specified using the syntax described in thread-id syntax. If multiprocess extensions (see multiprocess extensions) are supported, actions can be specified to match all threads in a process by using the ‘… text/html 2026-03-02T23:44:34+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_vcont_qm?rev=1772495074&do=diff command vCont? Format: ‘!’ Meaning: Request a list of actions supported by the ‘vCont’ packet. Reply: ‘vCont[;action…]’ The ‘vCont’ packet is supported. Each action is a supported command in the ‘vCont’ packet. text/html 2026-03-02T23:45:34+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_vctrl?rev=1772495134&do=diff command vCtrlC Format: ‘vCtrlC’ Meaning: Interrupt remote target as if a control-C was pressed on the remote terminal. This is the equivalent to reacting to the ^C (‘\003’, the control-C character) character in all-stop mode while the target is running, except this works in non-stop mode. text/html 2026-03-02T23:46:07+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_vfile?rev=1772495167&do=diff command vFile Format: ‘vFile:operation:parameter…’ Meaning: Perform a file operation on the target system. text/html 2026-03-02T23:47:18+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_vflashdone?rev=1772495238&do=diff command vFlashDone Format: ‘vFlashDone’ Meaning: Indicate to the stub that flash programming operation is finished. The stub is permitted to delay or batch the effects of a group of ‘vFlashErase’ and ‘vFlashWrite’ packets until a ‘vFlashDone’ packet is received. The contents of the affected regions of flash memory are unpredictable until the ‘vFlashDone’ request is completed. text/html 2026-03-02T23:46:31+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_vflasherase?rev=1772495191&do=diff command vFlashErase Format: ‘vFlashErase:addr,length’ Meaning: Direct the stub to erase length bytes of flash starting at addr. The region may enclose any number of flash blocks, but its start and end must fall on block boundaries, as indicated by the flash block size appearing in the memory map. GDB groups flash memory programming operations together, and sends a ‘vFlashDone’ request after each group; the stub is allowed to delay erase operation until the ‘vFlashDone’ packet is received.… text/html 2026-03-02T23:46:56+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_vflashwrite?rev=1772495216&do=diff command vFlashWrite Format: ‘vFlashWrite:addr:XX…’ Meaning: Direct the stub to write data to flash address addr. The data is passed in binary form using the same encoding as for the ‘X’ packet (see Binary Data). The memory ranges specified by ‘vFlashWrite’ packets preceding a ‘vFlashDone’ packet must not overlap, and must appear in order of increasing addresses (although ‘vFlashErase’ packets for higher addresses may already have been received; the ordering is guaranteed only between ‘vFlashWr… text/html 2026-03-02T23:47:38+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_vkill?rev=1772495258&do=diff command vKill Format: ‘vKill;pid’ Meaning: Kill the process with the specified process ID pid, which is a hexadecimal integer identifying the process. This packet is used in preference to ‘k’ when multiprocess protocol extensions are supported. text/html 2026-03-02T23:48:00+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_vmustreplyempty?rev=1772495280&do=diff command vMustReplyEmpty Format: ‘vMustReplyEmpty’ Meaning: The correct reply to an unknown ‘v’ packet is to return the empty string, however, some older versions of gdbserver would incorrectly return ‘OK’ for unknown ‘v’ packets. The ‘vMustReplyEmpty’ is used as a feature test to check how gdbserver handles unknown packets, it is important that this packet be handled in the same way as other unknown ‘v’ packets. If this packet is handled differently to other unknown ‘v’ packets then it is pos… text/html 2026-03-02T23:48:22+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_vrun?rev=1772495302&do=diff command vRun Format: ‘vRun;filename[;argument]…’ Meaning: Run the program filename, passing it each argument on its command line. The file and arguments are hex-encoded strings. If filename is an empty string, the stub may use a default program (e.g. the last program run). The program is created in the stopped state. text/html 2026-03-02T23:48:53+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cmd_vstopped?rev=1772495333&do=diff command vStopped Format: ‘vStopped’ Meaning: TODO text/html 2026-04-06T13:28:05+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:cortex_m0p?rev=1775482085&do=diff ARM Cortex-M 0+ Memory Map start address end address used for comment 0x00 00 00 00 0x1F FF FF FF Code 0x20 00 00 00 0x3F FF FF FF SRAM 0x40 00 00 00 0x5F FF FF FF Peripheral 0x60 00 00 00 0x7F FF FF FF RAM 0x80 00 00 00 text/html 2026-03-02T23:03:41+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:gdb_server_protocol?rev=1772492621&do=diff gdb server protocol The gdb server protocol is used in a debug setup between gdb and the gdbserver. The gdbserver is the driver/software interface of the JATG/SWD probe. This allows the user to use an(optional) IDE with gdb to debug firmware running on a MCU. text/html 2026-03-02T23:55:06+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:notification_stop?rev=1772495706&do=diff notifications These are packets that go from the gdb server to gdb. A notification packet has the form ‘% data # checksum’, where data is the content of the notification, and checksum is a checksum of data, computed and formatted as for ordinary GDB packets. A notification’s data never contains ‘$’, ‘%’ or ‘#’ characters. Upon receiving a notification, the recipient sends no ‘+’ or ‘-’ to acknowledge the notification’s receipt or to report its corruption. text/html 2026-03-02T23:10:37+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:packets?rev=1772493037&do=diff packets all packets: “$packet-data#checksum” notification packets: “%data#checksum” ( Example : %Stop:...) The two-digit checksum is computed as the modulo 256 sum of all characters between the leading ‘$’ and the trailing ‘#’ (an eight bit unsigned checksum). text/html 2026-03-02T23:50:49+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:reply_empty?rev=1772495449&do=diff empty reply Format: '' ( $#00) Meaning: gdb-server does not understand / support / implement the command. Example: $#00 text/html 2026-03-02T23:51:31+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:reply_e_text?rev=1772495491&do=diff error (text) reply Format: ‘E.errtext’ Meaning: An error has occurred on the gdb-server. The errtext is the error message. Example: $E.Target not connected#00 Reports error “Target not connected”. text/html 2026-03-02T23:51:09+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:reply_e_xx?rev=1772495469&do=diff error (hex) reply Format: ‘E xx’ Meaning: The error with number xx has occurred on the gdb-server. The Errors are in the range 0x00 to 0xff. Example: $E05#00 Reports error 0x05. text/html 2026-03-02T23:52:43+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:reply_stop_lc_w?rev=1772495563&do=diff stopped thread exited reply Format: ‘w AA ; tid’ Meaning: The thread exited, and AA is the exit status. This response should not be sent by default; GDB requests it with either the QThreadEvents or QThreadOptions packets. AA is formatted as a big-endian hex string. text/html 2026-03-02T23:54:42+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:reply_stop_uc_f?rev=1772495682&do=diff host function call reply Format: ‘F call-id,parameter…’ Meaning: call-id is the identifier which says which host system call should be called. This is just the name of the function. Translation into the correct system call is only applicable as it’s defined in GDB. The File-I/O Remote Protocol Extension defines the list of implemented system calls. text/html 2026-03-02T23:54:02+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:reply_stop_uc_n?rev=1772495642&do=diff stopped no more threads reply Format: ‘N’ Meaning: There are no resumed threads left in the target. In other words, even though the process is alive, the last resumed thread has exited. For example, say the target process has two threads: thread 1 and thread 2. The client leaves thread 1 stopped, and resumes thread 2, which subsequently exits. At this point, even though the process is still alive, and thus no ‘W’ stop reply is sent, no thread is actually executing either. The ‘N’ stop reply th… text/html 2026-03-02T23:54:21+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:reply_stop_uc_o?rev=1772495661&do=diff console output reply Format: ‘O XX…’ Meaning: ‘XX…’ is hex encoding of ASCII data, to be written as the program’s console output. This can happen at any time while the program is running and the debugger should continue to wait for ‘W’, ‘T’, etc. This reply is not permitted in non-stop mode. text/html 2026-03-02T23:51:53+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:reply_stop_uc_s?rev=1772495513&do=diff stopped reply Format: ‘S AA’ Meaning: The program received signal number AA (a two-digit hexadecimal number). Example: $S05#00 signal numbers are defined in include/gdb/signals.h. text/html 2026-03-02T23:52:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:reply_stop_uc_t?rev=1772495537&do=diff stopped + infos reply Format: ‘T AA n1:r1;n2:r2;…’ Meaning: The program received signal number AA (a two-digit hexadecimal number). Each ‘n:r’ pair is interpreted as follows: * If n is a hexadecimal number, it is a register number, and the corresponding r gives that register’s value. The data r is a series of bytes in target byte order, with each byte given by a two-digit hex number. text/html 2026-03-02T23:53:02+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:reply_stop_uc_w?rev=1772495582&do=diff stopped process reply Format: ‘W AA [; process:pid]’ Meaning: The process exited, and AA is the exit status. This is only applicable to certain targets. The optional process ID of the exited process, can be used only when GDB has reported support for multiprocess protocol extensions; see multiprocess extensions. Both AA and pid are formatted as big-endian hex strings. text/html 2026-03-02T23:53:38+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:reply_stop_uc_x?rev=1772495618&do=diff stopped process exited reply Format: ‘X AA [; process:pid]’ Meaning: The process terminated with signal AA. The optional process ID of the terminated process, can be used only when GDB has reported support for multiprocess protocol extensions. Both AA and pid are formatted as big-endian hex strings. text/html 2026-03-02T23:09:59+00:00 Anonymous (anonymous@undisclosed.example.com) http://mbsp/ref:signals?rev=1772492999&do=diff signals from include/gdb/signals.h Target signal numbers for GDB and the GDB remote protocol. signal number signal name explanation 0 Signal 0 Used some places (e.g. stop_signal) to record the concept that there is no signal. 1 SIGHUP Hangup