[PATCH v7 2/2] Adding Trace Documentation
Vidushi Vashishth
reachvidu at gmail.com
Thu Jun 14 14:21:26 UTC 2018
The latest trace documentation images patch is version 5.
Thanks
On Thu, Jun 14, 2018 at 7:47 PM, Vidushi Vashishth <reachvidu at gmail.com>
wrote:
> - Updates #3454
> - This commit adds Tracing Framework Chapter in the RTEMS User Manual
> - It comprises of subchapters on RTEMS Trace Linker, Capture Engine, Trace
> generation techniques explaining trace generation using Trace Buffering
> and
> Printk generators and sample demonstrations.
> ---
> user/index.rst | 2 +
> user/tracing/captureengine.rst | 169 ++++++++++++++
> user/tracing/examples.rst | 199 +++++++++++++++++
> user/tracing/index.rst | 29 +++
> user/tracing/introduction.rst | 103 +++++++++
> user/tracing/tracelinker.rst | 494 ++++++++++++++++++++++++++++++
> +++++++++++
> 6 files changed, 996 insertions(+)
> create mode 100644 user/tracing/captureengine.rst
> create mode 100644 user/tracing/examples.rst
> create mode 100644 user/tracing/index.rst
> create mode 100644 user/tracing/introduction.rst
> create mode 100644 user/tracing/tracelinker.rst
>
> diff --git a/user/index.rst b/user/index.rst
> index 8cbcd1b..a764fe8 100644
> --- a/user/index.rst
> +++ b/user/index.rst
> @@ -52,6 +52,8 @@ to the Community Project hosted at http://www.rtems.org/
> .
>
> tools/index
>
> + tracing/index
> +
> support/index
>
> glossary/index
> diff --git a/user/tracing/captureengine.rst b/user/tracing/captureengine.
> rst
> new file mode 100644
> index 0000000..8eaed3b
> --- /dev/null
> +++ b/user/tracing/captureengine.rst
> @@ -0,0 +1,169 @@
> +.. comment SPDX-License-Identifier: CC-BY-SA-4.0
> +
> +.. comment: Copyright (c) 2018 Vidushi Vashishth <
> vidushivashishth96 at gmail.com>
> +.. comment: All rights reserved.
> +
> +.. _capturengine:
> +
> +Capture Engine
> +**************
> +
> +Capture Engine is a trace tool built inside the RTEMS operating system.
> Capture
> +Engine is designed to cause the lowest load on the system when operating.
> Hence
> +it does not effect RTEMS when operating or when disabled. It binds to
> RTEMS at
> +runtime and does not require RTEMS or your application to be rebuilt in
> order
> +to use it.
> +
> +The Capture Engine's sample testcase for the `sparc/erc32` is available in
> +build directory created when building RTEMS in the path
> +file: `sparc-rtems5/c/erc32/testsuites/samples`. In order to access the
> capture
> +testcase perform the following set of operations inside the RTEMS build
> +directory.
> +
> +.. code-block:: shell
> +
> + $ cd /sparc-rtems5/c/erc32/testsuites/samples
> + $ sparc-rtems5-run ./capture.exe
> +
> +
> + *** BEGIN OF TEST CAPTURE ENGINE ***
> + *** TEST VERSION: 5.0.0.de9b7d712bf5da6593386fd4fbca0d5f8b8431d8
> + *** TEST STATE: USER_INPUT
> + *** TEST BUILD: RTEMS_NETWORKING RTEMS_POSIX_API
> + *** TEST TOOLS: 7.3.0 20180125 (RTEMS 5, RSB
> a3a6c34c150a357e57769a26a460c475e188438f, Newlib 3.0.0)
> + Press any key to start capture engine (20s remaining)
> + Press any key to start capture engine (19s remaining)
> + Press any key to start capture engine (18s remaining)
> +
> + Monitor ready, press enter to login.
> +
> + 1-rtems $
> +
> +Capture Engine comes with a set of commands to perform various actions.
> +
> +Capture Engine Commands
> +-----------------------
> +
> +1) ``copen <buffer-size>``: Used to initialize the Capture Engine with the
> + trace buffer size in bytes. By default the Capture Engine is not
> initialized
> + and not running.
> +
> +2) ``cwceil <priority-value>``: Capture Engine filter used to put an upper
> + limit on the event priority to be captured.
> +
> +3) ``cwfloor <priority-value>``: Capture Engine filter used to put a lower
> + limit on the event priority to be captured.
> +
> +4) ``cwglob <on/off>``: Enable or disable the global watch.
> +
> +5) ``cenable``: Enables the Capture Engine. Capture Engine is by default
> + disabled after being opened.
> +
> +6) ``cdisable``: Disables the Capture Engine.
> +
> +7) ``ctlist``: Lists the watch and trigger configurations.
> +
> +8) ``ctrace``: Dumps the recorded traces. By default this command
> displays 24
> + trace records. Repeated use of this command will display all the
> recorded
> + traces.
> +
> +9) ``cwadd <task-name>``: Add watch on a particular task.
> +
> +10) ``cwtctl <task-name> <on/off>``: Enable or disable watch on a
> particular
> + task.
> +
> +11) ``ctset``: Used to set a trigger. The general form of the command is:
> +
> +``ctset [-?] type [to name/id] [from] [from name/id]``
> +
> +`type` in the above command refers to the type of trigger needed. The
> types of
> +triggers that currently exist are:
> +
> +- switch : a context switch from one task to another task
> +- create : the executing task creates a task
> +- start : the executing task starts a task
> +- restart : the executing task restarts a task
> +- delete : the executing task deletes a task
> +- begin : a task is beginning
> +- exitted : a task is exitting
> +
> +Example
> +-------
> +
> +The following is a sample run of the capture testsuite. The `test1`
> command on
> +the Capture Engine Command Line Interface (CLI) makes the `RMON` task
> invoke a
> +call to the `capture_test_1()` command. This function (in the `test1.c`
> source
> +code) creates and starts three tasks : `CT1a`, `CT1b` and `CT1c`. These
> tasks
> +are passed the object id of a semaphore as a task argument. This run
> through
> +traces the context switches between these tasks. ``cwceil`` and
> ``cwfloor`` are
> +set to a narrow range of task priorities to avoid creating noise from a
> large
> +number of context switches between tasks we are not interested in.
> +
> +.. code:: shell
> +
> + *** BEGIN OF TEST CAPTURE ENGINE ***
> + *** TEST VERSION: 5.0.0.de9b7d712bf5da6593386fd4fbca0d5f8b8431d8
> + *** TEST STATE: USER_INPUT
> + *** TEST BUILD: RTEMS_NETWORKING RTEMS_POSIX_API
> + *** TEST TOOLS: 7.3.0 20180125 (RTEMS 5, RSB
> a3a6c34c150a357e57769a26a460c475e188438f, Newlib 3.0.0)
> + Press any key to start capture engine (20s remaining)
> + Press any key to start capture engine (19s remaining)
> + Press any key to start capture engine (18s remaining)
> + Press any key to start capture engine (17s remaining)
> +
> + Monitor ready, press enter to login.
> +
> + 1-rtems $ copen 50000
> + capture engine opened.
> + 1-rtems $ cwceil 100
> + watch ceiling is 100.
> + 1-rtems $ cwfloor 102
> + watch floor is 102.
> + 1-rtems $ cwglob on
> + global watch enabled.
> + 1-rtems $ ctset RMON
> + trigger set.
> + 1-rtems $ cenable
> + capture engine enabled.
> + 1-rtems $ test1
> + 1-rtems $ cdisable
> + capture engine disabled.
> + 1-rtems $ ctrace
> + 0 0:18:17.462314124 0a010003 CT1a 102 102 102 4096
> TASK_RECORD
> + 0 0:18:17.462398963 0 0a010003 CT1a 102 102 CREATED
> + 0 0:18:17.462647987 249024 0a010003 CT1a 102 102 STARTED
> + 0 0:18:17.462904334 256347 0a010003 CT1a 102 102
> SWITCHED_IN
> + 0 0:18:17.463069129 164795 0a010003 CT1a 102 102 BEGIN
> + 0 0:18:17.463335853 266724 0a010003 CT1a 102 102
> SWITCHED_OUT
> + 0 0:18:18.461348547 0a010004 CT1b 101 101 101 4096
> TASK_RECORD
> + 0 0:18:18.461433997 998098144 0a010004 CT1b 101 101 CREATED
> + 0 0:18:18.461683631 249634 0a010004 CT1b 101 101 STARTED
> + 0 0:18:18.461934485 250854 0a010004 CT1b 101 101
> SWITCHED_IN
> + 0 0:18:18.462099891 165406 0a010004 CT1b 101 101 BEGIN
> + 0 0:18:19.460935339 998835448 0a010004 CT1b 101 101
> SWITCHED_OUT
> + 0 0:18:19.461431555 0a010005 CT1c 100 100 100 4096
> TASK_RECORD
> + 0 0:18:19.461516394 581055 0a010005 CT1c 100 100 CREATED
> + 0 0:18:19.461765418 249024 0a010005 CT1c 100 100 STARTED
> + 0 0:18:19.462019324 253906 0a010005 CT1c 100 100
> SWITCHED_IN
> + 0 0:18:19.462184119 164795 0a010005 CT1c 100 100 BEGIN
> + 0 0:18:19.462475257 291138 0a010005 CT1c 100 100
> SWITCHED_OUT
> + 0 0:18:19.462551551 76294 0a010004 CT1b 101 101
> SWITCHED_IN
> + 0 0:18:19.960935645 498384094 0a010004 CT1b 101 101
> SWITCHED_OUT
> + 0 0:18:19.961012549 76904 0a010003 CT1a 102 100
> SWITCHED_IN
> + 0 0:18:19.961341528 328979 0a010003 CT1a 102 102
> SWITCHED_OUT
> + 1-rtems $ ctrace
> + 0 0:18:19.961418433 0 0a010005 CT1c 100 100
> SWITCHED_IN
> + 0 0:18:19.961672339 253906 0a010005 CT1c 100 100
> SWITCHED_OUT
> + 0 0:18:19.961749854 77515 0a010004 CT1b 101 101
> SWITCHED_IN
> + 0 0:18:20.460967077 499217223 0a010004 CT1b 101 101
> SWITCHED_OUT
> + 0 0:18:20.461219763 252686 0a010005 CT1c 100 100
> SWITCHED_IN
> + 0 0:18:20.461424231 204468 0a010005 CT1c 100 100
> TERMINATED
> + 0 0:18:20.461747107 322876 0a010005 CT1c 100 100
> SWITCHED_OUT
> + 0 0:18:20.461824011 76904 0a010004 CT1b 101 101
> SWITCHED_IN
> + 0 0:18:20.462015052 191041 0a010004 CT1b 101 101
> TERMINATED
> + 0 0:18:20.462336707 321655 0a010004 CT1b 101 101
> SWITCHED_OUT
> + 0 0:18:20.462414222 77515 0a010003 CT1a 102 102
> SWITCHED_IN
> + 0 0:18:20.462608924 194702 0a010003 CT1a 102 102
> TERMINATED
> + 0 0:18:20.462933021 324097 0a010003 CT1a 102 102
> SWITCHED_OUT
> + 1-rtems $ ctrace
> + 1-rtems $
> diff --git a/user/tracing/examples.rst b/user/tracing/examples.rst
> new file mode 100644
> index 0000000..a694bff
> --- /dev/null
> +++ b/user/tracing/examples.rst
> @@ -0,0 +1,199 @@
> +.. comment SPDX-License-Identifier: CC-BY-SA-4.0
> +
> +.. comment: Copyright (c) 2018 Vidushi Vashishth <
> vidushivashishth96 at gmail.com>
> +.. comment: All rights reserved.
> +
> +.. _examples:
> +
> +Tracing Examples
> +****************
> +
> +The following example executes RTEMS trace using trace buffering for the
> +`fileio` sample testcase.
> +
> +Features
> +--------
> +
> +Tracing using trace buffering consists of the following sets of features:
> +
> +- Individual entry and exit records.
> +- Task details such as CPU, current priority, real priority, task state
> and
> + interrupt state.
> +- Nano-second timestamp.
> +- Interrupt safe buffer management.
> +- Function argument capture.
> +- Return value capture.
> +- Shell command support to report to the console, save a buffer, assess
> status
> + of tracing, or view buffers between specified index ranges.
> +
> +Prerequisites
> +-------------
> +
> +1. Setup RTEMS for the `sparc/erc32` architecture-bsp pair to run the
> + following example.
> +2. Download the fileio `configuration file <https://devel.rtems.org/
> attachment
> + /wiki/Developer/Tracing/Trace_Buffering/fileio-trace.ini>`_ and store
> it on
> + the top of the installed BSP's directory.
> +3. Change the value of the keys: `rtems-path` and `prefix` according to
> your
> + rtems installation. The `rtems-path` is the path to the bsp
> installation
> + and `prefix` is the path to the tools used to build rtems. Also set the
> + value of the `rtems-bsp` key to `sparc/erc32`.
> +
> +Demonstration
> +-------------
> +
> +Inside the RTEMS build directory (the directory where the fileio
> configuration
> +has been stored) run the following commands to generate traces:
> +
> +BSP is configured with the following command -
> +
> +.. code:: shell
> +
> + ../rtems/configure --target=sparc-rtems5 --prefix=/development/rtems/5 \
> + --enable-networking --enable-tests --enable-rtemsbsp=erc32 --enable-cxx
> +
> +The next two commands are used to link the fileio executable.The `-B`
> option
> +signifies the use of the complete path to the required directory or file.
> Write
> +the full path instead of the path file: `sparc-rtems5/erc32/lib/` in the
> +following commands according to your installation. Also confirm the path
> of the
> +fileio’s executable and object files in the last line of the command
> according
> +to your installation.
> +
> +.. code:: shell
> +
> + sparc-rtems5-gcc -Bsparc-rtems5/erc32/lib/ \
> + -specs bsp_specs -qrtems -mcpu=cypress -O2 -g -ffunction-sections \
> + -fdata-sections -Wall -Wmissing-prototypes -Wimplicit-function-declaration
> \
> + -Wstrict-prototypes -Wnested-externs -Wl,--gc-sections -mcpu=cypress \
> + -o sparc-rtems5/c/erc32/testsuites/samples/fileio.exe
> sparc-rtems5/c/erc32/\
> + testsuites/samples/fileio/fileio-init.o
> +
> +This is the trace linker command to generate and compile the wrapper c
> file for
> +the application. The link command follows the escape sequence "--". "-C"
> option
> +denotes the name of the user configuration file and "-W" specifies the
> name of
> +the wrapper c file.
> +
> +.. code:: shell
> +
> + rtems-tld -C fileio-trace.ini -W fileio-wrapper --
> -Bsparc-rtems5/erc32/lib/ \
> + -specs bsp_specs -qrtems -mcpu=cypress -O2 -g -ffunction-sections \
> + -fdata-sections -Wall -Wmissing-prototypes -Wimplicit-function-declaration
> \
> + -Wstrict-prototypes -Wnested-externs -Wl,--gc-sections -mcpu=cypress \
> + -o sparc-rtems5/c/erc32/testsuites/samples/fileio.exe
> sparc-rtems5/c/erc32/\
> + testsuites/samples/fileio/fileio-init.o
> +
> +The following command is used to run the application. Hit enter key
> quickly and
> +type "s" and "root" and "pwd" to run the rtems shell. Use the `rtrace
> status`,
> +`rtrace trace` and `rtrace save` commands to know the status of the
> tracing,
> +display the contents of the trace buffer and save the buffer to disk in
> the form
> +of binary files. Use `rtrace -l` to list the availalble options for
> commands
> +with `rtrace`.
> +
> +.. code:: shell
> +
> + sparc-rtems5-run sparc-rtems5/c/erc32/testsuites/samples/fileio.exe
> +
> +The output from the above commands will be as follows:
> +
> +.. code:: shell
> +
> + *** BEGIN OF TEST FILE I/O ***
> + *** TEST VERSION: 5.0.0.de9b7d712bf5da6593386fd4fbca0d5f8b8431d8
> + *** TEST STATE: USER_INPUT
> + *** TEST BUILD: RTEMS_NETWORKING RTEMS_POSIX_API
> + *** TEST TOOLS: 7.3.0 20180125 (RTEMS 5, RSB
> a3a6c34c150a357e57769a26a460c475e188438f, Newlib 3.0.0)
> + Press any key to start file I/O sample (20s remaining)
> + Press any key to start file I/O sample (19s remaining)
> + Press any key to start file I/O sample (18s remaining)
> + Press any key to start file I/O sample (17s remaining)
> + Press any key to start file I/O sample (16s remaining)
> + Press any key to start file I/O sample (15s remaining)
> + Press any key to start file I/O sample (14s remaining)
> + =========================
> + RTEMS FILE I/O Test Menu
> + =========================
> + p -> part_table_initialize
> + f -> mount all disks in fs_table
> + l -> list file
> + r -> read file
> + w -> write file
> + s -> start shell
> + Enter your selection ==>s
> + Creating /etc/passwd and group with four useable accounts:
> + root/pwd
> + test/pwd
> + rtems/NO PASSWORD
> + chroot/NO PASSWORD
> + Only the root user has access to all available commands.
> + =========================
> + starting shell
> + =========================
> +
> + Welcome to rtems-5.0.0 (SPARC/w/FPU/erc32)
> + COPYRIGHT (c) 1989-2008.
> + On-Line Applications Research Corporation (OAR).
> +
> + Login into RTEMS
> + /dev/foobar login: root
> + Password:
> +
> + RTEMS Shell on /dev/foobar. Use 'help' to list commands.
> + SHLL [/] # rtrace status
> + RTEMS Trace Bufferring: status
> + Running: yes
> + Triggered: yes
> + Level: 0%
> + Traces: 25
> + SHLL [/] # rtrace stop
> + RTEMS Trace Bufferring: stop
> + SHLL [/] # rtrace trace
> + RTEMS Trace Bufferring: trace
> + Trace buffer: 0x20921d8
> + Words traced: 1487
> + Traces: 25
> + 0:00:40.983197010 2081910 0a010002 [ 2/ 2] > malloc((size_t)
> 00000130)
> + 0:00:40.983333119 136109 0a010002 [ 2/ 2] < malloc => (void*)
> 0x219bb88
> + 0:00:40.983471669 138550 0a010002 [ 2/ 2] > malloc((size_t)
> 00000006)
> + 0:00:40.983606557 134888 0a010002 [ 2/ 2] < malloc => (void*)
> 0x219bcc0
> + 0:00:40.983684682 78125 0a010002 [ 2/ 2] > malloc((size_t)
> 00000007)
> + 0:00:40.983819569 134887 0a010002 [ 2/ 2] < malloc => (void*)
> 0x219bcd0
> + 0:00:40.983909901 90332 0a010002 [ 2/ 2] > malloc((size_t)
> 000003fc)
> + 0:00:40.984046620 136719 0a010002 [ 2/ 2] < malloc => (void*)
> 0x219bce0
> + 0:00:40.986624137 2577517 0a010003 [200/200] > malloc((size_t)
> 00000080)
> + 0:00:40.986767569 143432 0a010003 [200/200] < malloc => (void*)
> 0x219bce0
> + 0:00:40.987531119 763550 0a010003 [200/200] > calloc((size_t)
> 00000001, (size_t) 0000005d)
> + 0:00:40.987603751 72632 0a010003 [200/200] > malloc((size_t)
> 0000005d)
> + 0:00:40.987744743 140992 0a010003 [200/200] < malloc => (void*)
> 0x219bce0
> + 0:00:40.987824699 79956 0a010003 [200/200] < calloc => (void*)
> 0x219bce0
> + 0:00:40.988302604 477905 0a010003 [200/200] > malloc((size_t)
> 00000080)
> + 0:00:40.988446647 144043 0a010003 [200/200] < malloc => (void*)
> 0x219bd48
> + 0:00:40.988667595 220948 0a010003 [200/200] > calloc((size_t)
> 00000001, (size_t) 00000080)
> + 0:00:40.988740837 73242 0a010003 [200/200] > malloc((size_t)
> 00000080)
> + 0:00:40.988884880 144043 0a010003 [200/200] < malloc => (void*)
> 0x219bdd0
> + 0:00:40.988964836 79956 0a010003 [200/200] < calloc => (void*)
> 0x219bdd0
> + 0:00:40.989042961 78125 0a010003 [200/200] > calloc((size_t)
> 00000001, (size_t) 00000080)
> + 0:00:40.989110100 67139 0a010003 [200/200] > malloc((size_t)
> 00000080)
> + 0:00:40.989254143 144043 0a010003 [200/200] < malloc => (void*)
> 0x219be58
> + 0:00:40.989334099 79956 0a010003 [200/200] < calloc => (void*)
> 0x219be58
> + 0:00:40.990118401 784302 0a010003 [200/200] > calloc((size_t)
> 00000001, (size_t) 00000061)
> + 0:00:40.990176995 58594 0a010003 [200/200] > malloc((size_t)
> 00000061)
> + 0:00:40.990309441 132446 0a010003 [200/200] < malloc => (void*)
> 0x219bd48
> + 0:00:40.990384515 75074 0a010003 [200/200] < calloc => (void*)
> 0x219bd48
> + 0:00:40.990870355 485840 0a010003 [200/200] > malloc((size_t)
> 00000080)
> + 0:00:40.991011346 140991 0a010003 [200/200] < malloc => (void*)
> 0x219bee0
> + 0:00:40.991227411 216065 0a010003 [200/200] > calloc((size_t)
> 00000001, (size_t) 00000080)
> + 0:00:40.991296380 68969 0a010003 [200/200] > malloc((size_t)
> 00000080)
> + 0:00:40.991438593 142213 0a010003 [200/200] < malloc => (void*)
> 0x219bf68
> + 0:00:40.991514276 75683 0a010003 [200/200] < calloc => (void*)
> 0x219bf68
> + 0:00:40.991589349 75073 0a010003 [200/200] > calloc((size_t)
> 00000001, (size_t) 00000080)
> + 0:00:40.991653437 64088 0a010003 [200/200] > malloc((size_t)
> 00000080)
> + 0:00:40.991794428 140991 0a010003 [200/200] < malloc => (void*)
> 0x219bff0
> + 0:00:40.991871332 76904 0a010003 [200/200] < calloc => (void*)
> 0x219bff0
> + 0:00:40.992283320 411988 0a010003 [200/200] > malloc((size_t)
> 00000008)
> + SHLL [/] # rtrace save fileio-trace.bin
> + RTEMS Trace Bufferring: trace
> + Trace File: fileio-trace.bin
> + Trace buffer: 0x20921d8
> + Words traced: 1487
> + Traces: 25
> + SHLL [/] #
> diff --git a/user/tracing/index.rst b/user/tracing/index.rst
> new file mode 100644
> index 0000000..0d714bc
> --- /dev/null
> +++ b/user/tracing/index.rst
> @@ -0,0 +1,29 @@
> +.. comment SPDX-License-Identifier: CC-BY-SA-4.0
> +
> +.. comment: Copyright (c) 2016 Chris Johns <chrisj at rtems.org>
> +.. comment: All rights reserved.
> +
> +.. _tracing-framework:
> +
> +RTEMS Tracing Framework
> +***********************
> +.. index:: Tracing Framework
> +
> +RTEMS Tracing Framework is an on-target software based system which helps
> track
> +the ongoings inside the operation of applications, 3rd party packages,
> and the
> +kernel in real time.
> +
> +Software based tracing is a complex process which requires components on
> both
> +the target and the host to work together. However its portability across
> all
> +architectures and board support packages makes it a useful asset. A key
> +requirement in RTEMS trace process is to take existing code in compiled
> format
> +(ELF) and instrument it in order to log various events and records in
> real time.
> +However instrumenting of the code for tracing should happen without
> rebuilding
> +the code from the source and without annotating the source with trace
> code.
> +
> +.. toctree::
> +
> + introduction
> + examples
> + captureengine
> + tracelinker
> diff --git a/user/tracing/introduction.rst b/user/tracing/introduction.rst
> new file mode 100644
> index 0000000..27de441
> --- /dev/null
> +++ b/user/tracing/introduction.rst
> @@ -0,0 +1,103 @@
> +.. comment SPDX-License-Identifier: CC-BY-SA-4.0
> +
> +.. comment: Copyright (c) 2016 Chris Johns <chrisj at rtems.org>
> +.. comment: All rights reserved.
> +
> +.. _introduction:
> +
> +Introduction to Tracing
> +***********************
> +
> +Tracing is an important function which has several applications including
> +identification of complex threading, detection of deadlocks, tracing
> +functions along with their argument values, and return values through
> +progression of several function calls and audit the performance of an
> +application according to required specifications.
> +
> +RTEMS tracing framework is under development and welcomes contribution by
> users.
> +
> +RTEMS has the following trace components:
> +
> +- RTEMS :ref:`tracelinker`
> +- RTEMS :ref:`capturengine`
> +- Common Trace Format Integration
> +
> +RTEMS trace framework can currently function using the following methods.
> Both
> +of the methods make use of the :ref:`tracelinker` :
> +
> +.. _tracebuffering:
> +
> +RTEMS Trace Using Trace Buffering
> +=================================
> +
> +This scheme of tracing goes through the flow of events described in a
> +subsequent flowchart:
> +
> +Step 1: The user creates an application and user configuration file. The
> +configuration file specifies the use of the trace buffer generator and
> other
> +standard initializations. The user then configures their BSP and invokes
> the
> +trace linker using a command to link the application executable. The trace
> +linker uses the application files in compiled format (ELF) and the
> libraries
> +used to build the application for performing this link.
> +
> +Step 2: The RTEMS Trace Linker reads the user’s configuration file and
> that
> +results in it reading the standard Trace Buffering Configuration files
> +installed with the RTEMS Trace Linker. The trace linker uses the target
> +compiler and linker to create the trace enabled application executable. It
> +wraps the functions defined in the user’s configuration with code that
> captures
> +trace records into the statically allocated buffer. The trace wrapper
> code is
> +compiled with the target compiler and the resulting ELF object file is
> added to
> +the standard link command line used to link the application and the
> application
> +is re-linked using the wrapping option of the GNU linker.
> +
> +Step 3: The trace linker creates an executable which is capable of
> running on
> +the target hardware or simulator.
> +
> +Step 4: RTEMS shell provides the “rtrace” command to display and save
> trace
> +buffers.
> +
> +.. comment: taken from https://devel.rtems.org/wiki/Developer/Tracing
> +.. figure:: ../../images/user/rtems-trace-buffering.png
> + :align: center
> + :width: 75%
> +
> +.. _printk:
> +
> +RTEMS Trace Using Printk
> +========================
> +
> +This scheme of tracing goes through the flow of events described in a
> subsequent
> +flowchart:
> +
> +Step 1: The user creates an RTEMS application in the normal manner as
> well as a
> +Trace Linker configuration file. The configuration file specifies using
> the
> +Printk trace mode and the functions to trace. The user invokes the Trace
> Linker
> +with the configuration and the normal link command line used to the link
> the
> +application executable. The application ELF object files and libraries,
> +including the RTEMS libraries are standard and do not need to be built
> +specially.
> +
> +Step 2: The RTEMS Trace Linker reads the user's configuration file and
> that
> +results in it reading the standard Printk Trace Configuration files
> installed
> +with the RTEMS Trace Linker. The trace linker uses the target compiler and
> +linker to create the trace enabled application executable. It wraps the
> +functions defined in the user's configuration with code that prints the
> entry
> +with arguments and exit and return value if any. The trace wrapper code is
> +compiled with the target compiler and the resulting ELF object file is
> added to
> +the standard link command line used to link the application and the
> application
> +is relinked using the wrapping option of the GNU linker.
> +
> +Step 3: The trace linker creates and RTEMS ELF executable that can be run
> on the
> +target hardware or simulator.
> +
> +Step 4: The application is run in the hardware directly or using a
> debugger. The
> +printk() output appears on the target console and the user can save that
> to a
> +file.
> +
> +.. comment: taken from https://devel.rtems.org/wiki/Developer/Tracing
> +.. figure:: ../../images/user/rtems-trace-printk.png
> + :align: center
> + :width: 75%
> +
> +The :ref:`examples` section describes generation of traces using Trace
> Buffering
> +technique for the `fileio` testsuite available with RTEMS installation.
> diff --git a/user/tracing/tracelinker.rst b/user/tracing/tracelinker.rst
> new file mode 100644
> index 0000000..ab42de6
> --- /dev/null
> +++ b/user/tracing/tracelinker.rst
> @@ -0,0 +1,494 @@
> +.. comment SPDX-License-Identifier: CC-BY-SA-4.0
> +
> +.. comment: Copyright (c) 2016 Chris Johns <chrisj at rtems.org>
> +.. comment: All rights reserved.
> +
> +.. _tracelinker:
> +
> +Trace Linker
> +************
> +
> +RTEMS trace linker is a post link tool central to the RTEMS trace
> framework. It
> +is installed as a part of the RTEMS Tool Project. The RTEMS Trace Linker
> is a
> +post link tool that performs a re-link of your application to produce a
> trace
> +executable. A trace executable has been instrumented by the RTEMS Trace
> Linker
> +with additional code that implements software tracing. A key requirement
> of the
> +trace process in RTEMS is to take existing code in a compiled format
> (ELF) and
> +instrument it without rebuilding that code from source and without
> annotating
> +that source with trace code.
> +
> +Command Line
> +============
> +
> +A typical command to invoke the trace linker consists of two parts
> separated by
> +``--``. The first part controls the trace linker and provides the various
> +options it needs and the second part is a standard linker command line
> you would
> +use to link an RTEMS application. The current command line for trace
> linker
> +consists of:
> +
> +.. code-block:: shell
> +
> + $ rtems-tld -h
> + rtems-trace-ld [options] objects
> + Options and arguments:
> + -h : help (also --help)
> + -V : print linker version number and exit (also --version)
> + -v : verbose (trace import parts), can supply multiple times
> + to increase verbosity (also --verbose)
> + -w : generate warnings (also --warn)
> + -k : keep temporary files (also --keep)
> + -c compiler : target compiler is not standard (also --compiler)
> + -l linker : target linker is not standard (also --linker)
> + -E prefix : the RTEMS tool prefix (also --exec-prefix)
> + -f cflags : C compiler flags (also --cflags)
> + -r path : RTEMS path (also --rtems)
> + -B bsp : RTEMS arch/bsp (also --rtems-bsp)
> + -W wrapper : wrapper file name without ext (also --wrapper)
> + -C ini : user configuration INI file (also --config)
> + -P path : user configuration INI file search path (also --path)
> +
> +The trace linker generates code that needs to be compiled and linked to
> the
> +application executable so it needs to know the target compiler and
> `CFLAGS`.
> +There are a couple of ways to do this. The simplest is to provide the
> path to
> +RTEMS using the `-r` option and the architecture and BSP name in the
> standard
> +RTEMS format of arch/bsp. The trace linker will extract the compiler and
> flags
> +used to build RTEMS and will use them. If you require specific options
> you can
> +use the `-f`, `-c`, `-l`, and `-E` options to provide them. If the
> functions you
> +are tracing use types from your code then add the include path to the
> `CFLAGS`.
> +
> +The trace linker requires you to provide a user configuration file using
> the
> +`-C` or ``--config`` option. This is an INI format file detailed in the
> +Configuration section. You can also provide an INI file search path using
> the
> +`-P` option.
> +
> +If you are working with new configuration files and you want to view the
> files
> +the trace linker generates, add the `-k` option to keep the temporary
> files, and
> +`-W` to specify an explicit wrapper C file name. If you set the
> +``dump-on-error`` option in the configuration options section you will
> get a
> +dump of the configuration on an error.
> +
> +Configuration (INI) files
> +=========================
> +
> +The Trace Linker is controlled using configuration files. Configuration
> files
> +are categorized into 3 types:
> +
> +- User Configuration: These are specific to the user application to be
> traced.
> + This file initializes the values of the trace generator, triggers,
> enables,
> + and traces.
> +
> +- Tracer Configuration: These are like a library of common or base trace
> + functions that can be referenced by an application. These files tend to
> hold
> + the details needed to wrap a specific set of functions. Examples
> provided with
> + the RTEMS Linker are the RTEMS API and Libc.
> +
> +- Generator Configuration: This is used to encapsulate a specific method
> of
> + tracing. RTEMS currently provides generators for trace buffering,
> printk, and
> + printf.
> +
> +The configuration files are in the *INI file format* which is composed of
> +`sections`. Each section has a section name and set of *keys* which
> consist of
> +*names* and *values*. A typical key is of the form ``name=value``. Keys
> can be
> +used to include other INI files using the include key name. This is shown
> in the
> +following example where the values indicate rtems and rtld-base
> configuration
> +files:
> +
> +.. code-block:: shell
> +
> + include = rtems.ini, rtld-base.ini
> +
> +The trace linker also uses values in keys to specify other sections. In
> this
> +example the functions name lists `test-trace-funcs` and that section
> contains a
> +headers key that further references a section called `test-headers`:
> +
> +.. code-block:: shell
> +
> + functions = test-trace-funcs, rtems-api
> +
> + [test-trace-funcs]
> + ; Parsed via the 'function-set', not parse as a 'trace'.
> + headers = test-headers
> +
> + [test-headers]
> + header = '#include "test-trace-1.h"'
> +
> +The format of a configuration file is explained next. Snippets of the
> file:
> +`test-trace.ini` have been used for explicit understanding. This file can
> +be found in the rtems-tools directory of the rtems installation.
> +
> +Tracer Section
> +--------------
> +
> +The topmost level section is the ``tracer`` section. It can contains the
> +following keys:
> +
> +- ``name``: The name of trace being linked.
> +
> +- ``options``: A list of option sections.
> +
> +- ``defines``: A list of sections containing defines or define record.
> +
> +- ``define``: A list of define string that are single or double quoted.
> +
> +- ``enables``: The list of sections containing enabled functions to trace.
> +
> +- ``triggers``: The list of sections containing enabled functions to
> trigger
> + trace on.
> +
> +- ``traces``: The list of sections containing function lists to trace.
> +
> +- ``functions``: The list of sections containing function details.
> +
> +- ``include``: The list of files to include.
> +
> +The tracer section of the file:`test-trace.ini` is shown below with
> explanatory
> +comments.
> +
> +.. code-block:: shell
> +
> + ;
> + ; RTEMS Trace Linker Test Configuration.
> + ;
> + ; We must provide a top level trace section.
> + ;
> + [tracer]
> + ;
> + ; Name of the trace.
> + ;
> + name = RTEMS Trace Linker Test
> + ;
> + ; The BSP.
> + ;
> + bsp = sparc/sis
> + ;
> + ; Functions to trace.
> + ;
> + traces = test-trace, test-trace-funcs, rtems-api-task
> + ;
> + ; Specify the options.
> + ;
> + options = test-options
> + ;
> + ; Define the function sets. These are the function's that can be
> + ; added to the trace lists.
> + ;
> + functions = test-trace-funcs, rtems-api
> + ;
> + ; Include RTEMS Trace support.
> + ;
> + include = rtems.ini, rtld-base.ini
> +
> +Options section
> +---------------
> +
> +The options section in the fileio-trace.ini is called the
> `fileio-options`. A
> +general options section can contain following sets of keys:
> +
> +- ``dump-on-error``: Dump the parsed configuration data on error. The
> value can
> + be true or false.
> +
> +- ``verbose``: Set the verbose level. The value can be true or a number
> value.
> +
> +- ``prefix``: The prefix for the tools and an install RTEMS if rtems-path
> is not
> + set.
> +
> +- ``cc``: The compiler used to compile the generated wrapper code.
> Overrides the
> + BSP configuration value if a BSP is specified.
> +
> +- ``ld``: The linker used to link the application. The default is the cc
> value
> + as read from the BSP configuration if specified. If your application
> contains
> + C++ code use this setting to the change the linker to g++.
> +
> +- ``cflags``: Set the CFLAGS used to compiler the wrapper. These flags are
> + pre-pended to the BSP read flags if a BSP is specified. This option is
> used
> + to provide extra include paths to header files in your application that
> + contain types referenced by functions being traced.
> +
> +- ``rtems-path``: The path to an install RTEMS if not installed under the
> + prefix.
> +
> +- ``rtems-bsp``: The BSP we are building the trace executable for. The is
> an
> + arch and bsp pair. For example sparc/erc32.
> +
> +The options section of the file: `test-trace.ini` uses two of the
> aforementioned
> +keys as shown below:
> +
> +.. code-block:: shell
> +
> + ;
> + ; Options can be defined here or on the command line.
> + ;
> + [test-options]
> + prefix = /development/rtems/5
> + verbose = true
> +
> +Trace Section
> +-------------
> +
> +A trace section defines how trace wrapper functions are built. To build a
> trace
> +function that wraps an existing function in an ELF object file or library
> +archive we need to have the function's signature. A signature is the
> function's
> +declaration with any types used. The signature has specific types and we
> need
> +access to those types which means the wrapper code needs to include
> header files
> +that define those types. There may also be specific defines needed to
> access
> +those types. A trace section can contain the following keys:
> +
> +- ``generator``: The generator defines the type of tracing being used.
> +
> +- ``headers``: List of sections that contain header file's keys.
> +
> +- ``header``: A header key. Typically the include code.
> +
> +- ``defines``: List of sections that contain defines.
> +
> +- ``define``: A define key. Typically the define code.
> +
> +- ``signatures``: List of function signature sections.
> +
> +- ``trace``: Functions that are instrumented with trace code.
> +
> +The trace section of the file: `test-trace.ini` is shown below. A trace
> section
> +can reference other trace sections of a specific type. This allows a trace
> +sections to build on other trace sections.
> +
> +.. code:: shell
> +
> + ; User application trace example.
> + ;
> + [test-trace]
> + generator = printf-generator
> + ; Just here for testing.
> + trace = test_trace_3
> +
> + [test-trace-funcs]
> + ; Parsed via the 'function-set', not parse as a 'trace'.
> + headers = test-headers
> + header = '#include "test-trace-2.h"'
> + defines = test-defines
> + define = "#define TEST_TRACE_2 2"
> + signatures = test-signatures
> + ; Parsed via the 'trace', not parsed as a function-set
> + trace = test_trace_1, test_trace_2
> +
> + [test-headers]
> + header = '#include "test-trace-1.h"'
> +
> + [test-defines]
> + define = "#define TEST_TRACE_1 1"
> +
> + [test-signatures]
> + test_trace_1 = void, int
> + test_trace_2 = test_type_2, test_type_1
> + test_trace_3 = float, float*
> +
> +Function Section
> +----------------
> +
> +Function sections define functions that can be traced. Defining a
> function so it
> +can be traced does not mean it is traced. The function must be added to a
> trace
> +list to be traced. Function sections provide any required defines, header
> files,
> +and the function signatures.
> +
> +A function signature is the function's declaration. It is the name of the
> +function, the return value, and the arguments. Tracing using function
> wrappers
> +requires that we have accurate function signatures and ideally we would
> like to
> +determine the function signature from the data held in ELF files. ELF
> files can
> +contain DWARF data, the ELF debugging data format. In time the trace
> project
> +would like to support libdwarf so the DWARF data can be accessed and used
> to
> +determine a function's signature. This work is planned but not scheduled
> to be
> +done and so in the meantime we explicitly define the function signatures
> in the
> +configuration files.
> +
> +A function section can consist of the following keys:
> +
> +- ``headers``: A list of sections containing headers or header records.
> +- ``header``: A list of include string that are single or double quoted.
> +- ``defines``: A list of sections containing defines or define record.
> +- ``defines``: A list of define string that are single or double quoted.
> +- ``signatures``: A list of section names of function signatures.
> +- ``includes``: A list of files to include.
> +
> +Function signatures are specified with the function name being the key's
> name
> +and the key's value being the return value and a list of function
> arguments. You
> +need to provide void if the function uses void. Variable argument list are
> +currently not supported. There is no way to determine statically a
> variable
> +argument list. The function section in the file: `test-trace.ini` has been
> +labeled as `test-trace-funcs`. This can be seen in the file snippet of the
> +previous section.
> +
> +Generators
> +----------
> +
> +The trace linker's major role is to wrap functions in the existing
> executable
> +with trace code. The directions on how to wrap application functions is
> provided
> +by the generator configuration. The wrapping function uses a GNU linker
> option
> +called --wrap=symbol. The GNU Ld manual states:
> +
> +"Use a wrapper function for symbol. Any undefined reference to symbol
> will be
> +resolved to __wrap_symbol. Any undefined reference to __real_symbol will
> be
> +resolved to symbol."
> +
> +Generator sections specify how to generate trace wrapping code. The trace
> +linker and generator section must match to work. The trace linker expects
> a some
> +things to be present when wrapping functions. The section's name
> specifies the
> +generator and can be listed in a generator key in a tracer or trace
> section. If
> +the generator is not interested in a specific phase it does not need to
> define
> +it. Nothing will be generated in regard to this phase. For example code to
> +profile specific functions may only provide the entry-trace and
> exit-trace code
> +where a nano-second time stamp is taken.
> +
> +The generate code will create an entry and exit call and the generator
> code
> +block can be used to allocate buffer space for each with the lock held.
> The
> +entry call and argument copy is performed with the lock released. The
> buffer
> +space having been allocated will cause the trace events to be in order.
> The same
> +goes for the exit call. Space is allocated in separate buffer allocate
> calls so
> +the blocking calls will have the exit event appear in the correct
> location in
> +the buffer.
> +
> +The following keys can be a part of the generator configuration:
> +
> +- ``headers``: A list of sections containing headers or header records.
> +- ``header``: A list of include string that are single or double quoted.
> +- ``defines``: A list of sections containing defines or define record.
> +- ``define``: A list of define string that are single or double quoted.
> +- ``entry-trace``: The wrapper call made on a function's entry. Returns
> bool
> + where true is the function is being traced. This call is made without
> the lock
> + being held if a lock is defined.
> +- ``arg-trace``: The wrapper call made for each argument to the trace
> function
> + if the function is being traced. This call is made without the lock
> being held
> + if a lock is defined.
> +- ``exit-trace``: The wrapper call made after a function's exit. Returns
> bool
> + where true is the function is being traced. This call is made without
> the lock
> + being held if a lock is defined.
> +- ``ret-trace``: The wrapper call made to log the return value if the
> function
> + is being traced. This call is made without the lock being held if a
> lock is
> + defined.
> +- ``lock-local``: The wrapper code to declare a local lock variable.
> +- ``lock-acquire``: The wrapper code to acquire the lock.
> +- ``lock-release``: The wrapper code to release the lock.
> +- ``buffer-local``: The wrapper code to declare a buffer index local
> variable.
> +- ``buffer-alloc``: The wrapper call made with a lock held if defined to
> + allocate buffer space to hold the trace data. A suitable 32bit buffer
> index is
> + returned. If there is no space an invalid index is returned. The
> generator
> + must handle any overhead space needed. The generator needs to make sure
> the
> + space is available before making the alloc all.
> +- ``code-blocks``: A list of code block section names.
> +- ``code``: A code block in <<CODE --- CODE (without the single quote).
> +- ``includes``: A list of files to include.
> +
> +The following macros can be used in wrapper calls:
> +
> +- ``@FUNC_NAME@``: The trace function name as a quote C string.
> +- ``@FUNC_INDEX@``: The trace function index as a held in the sorted
> list of
> + trace functions by the trace linker. It can be used to index the names,
> + enables, and triggers data.
> +- ``@FUNC_LABEL@``: The trace function name as a C label that can be
> referenced.
> + You can take the address of the label.
> +- ``@FUNC_DATA_SIZE@``: The size of the data in bytes.
> +- ``@FUNC_DATA_ENTRY_SIZE@``: The size of the entry data in bytes.
> +- ``@FUNC_DATA_RET_SIZE@``: The size of the return data in bytes.
> +- ``@ARG_NUM@``: The argument number to the trace function.
> +- ``@ARG_TYPE@``: The type of the argument as a C string.
> +- ``@ARG_SIZE@``: The size of the type of the argument in bytes.
> +- ``@ARG_LABEL@``: The argument as a C label that can be referenced.
> +- ``@RET_TYPE@``: The type of the return value as a C string.
> +- ``@RET_SIZE@``: The size of the type of the return value in bytes.
> +- ``@RET_LABEL@``: The return value as a C label that can be referenced.
> +
> +The `buffer-alloc`, `entry-trace`, and `exit-trace` can be transformed
> using the
> +following macros:
> +
> +- ``@FUNC_NAME@``
> +- ``@FUNC_INDEX@``
> +- ``@FUNC_LABEL@``
> +- ``@FUNC_DATA_SZIE@``
> +- ``@FUNC_DATA_ENTRY_SZIE@``
> +- ``@FUNC_DATA_EXIT_SZIE@``
> +
> +The `arg-trace` can be transformed using the following macros:
> +
> +- ``@ARG_NUM@``
> +- ``@ARG_TYPE@``
> +- ``@ARG_SIZE@``
> +- ``@ARG_LABEL@``
> +
> +The `ret-trace` can be transformed using the following macros:
> +
> +- ``@RET_TYPE@``
> +- ``@RET_SIZE@``
> +- ``@RET_LABEL@``
> +
> +The file: `test-trace.ini` specifies ``printf-generator`` as its
> generator. This
> +section can be found in the file: `rtld-print.ini` in the rtems-tools
> directory
> +and is shown below:
> +
> +.. code:: shell
> +
> + ;
> + ; A printf generator prints to stdout the trace functions.
> + ;
> + [printf-generator]
> + headers = printf-generator-headers
> + entry-trace = "rtld_pg_printf_entry(@FUNC_NAME@, (void*) &@FUNC_LABEL@
> );"
> + arg-trace = "rtld_pg_printf_arg(@ARG_NUM@, @ARG_TYPE@, @ARG_SIZE@,
> (void*) &@ARG_LABEL@);"
> + exit-trace = "rtld_pg_printf_exit(@FUNC_NAME@, (void*) &@FUNC_LABEL@);"
> + ret-trace = "rtld_pg_printf_ret(@RET_TYPE@, @RET_SIZE@, (void*)
> &@RET_LABEL@);"
> + code = <<<CODE
> + static inline void rtld_pg_printf_entry(const char* func_name,
> + void* func_addr)
> + {
> + printf (">>> %s (0x%08x)\n", func_name, func_addr);
> + }
> + static inline void rtld_pg_printf_arg(int arg_num,
> + const char* arg_type,
> + int arg_size,
> + void* arg)
> + {
> + const unsigned char* p = arg;
> + int i;
> + printf (" %2d] %s(%d) = ", arg_num, arg_type, arg_size);
> + for (i = 0; i < arg_size; ++i, ++p) printf ("%02x", (unsigned int)
> *p);
> + printf ("\n");
> + }
> + static inline void rtld_pg_printf_exit(const char* func_name,
> + void* func_addr)
> + {
> + printf ("<<< %s (0x%08x)\n", func_name, func_addr);
> + }
> + static inline void rtld_pg_printf_ret(const char* ret_type,
> + int ret_size,
> + void* ret)
> + {
> + const unsigned char* p = ret;
> + int i;
> + printf (" rt] %s(%d) = ", ret_type, ret_size);
> + for (i = 0; i < ret_size; ++i, ++p) printf ("%02x", (unsigned int)
> *p);
> + printf ("\n");
> + }
> + CODE
> +
> + [printf-generator-headers]
> + header = "#include <stdio.h>"
> +
> +The trace linker generates C code with a wrapper for each function to be
> +instrumented. The trace code generated is driven by the configuration INI
> files.
> +
> +Development
> +===========
> +
> +The Trace Linker is part of the RTEMS tools git repository available at :
> +https://git.rtems.org/rtems-tools
> +The RTEMS tools project utilizes the waf build system. Use the following
> +commands in the topmost build directory to build the tools project:
> +
> +First we configure using:
> +
> +.. code-block:: shell
> +
> + $./waf configure --prefix=$HOME/development/rtems/5
> +
> +Then we build and install using:
> +
> +.. code-block:: shell
> +
> + $./waf build install
> --
> 2.7.4
>
>
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