source: rtems-docs/shell/memory_commands.rst @ 8ca13ed

Memory Commands
###############

Introduction
============

The RTEMS shell has the following memory commands:

- ``mdump`` - Display contents of memory

- ``wdump`` - Display contents of memory (word)

- ``ldump`` - Display contents of memory (longword)

- ``medit`` - Modify contents of memory

- ``mfill`` - File memory with pattern

- ``mmove`` - Move contents of memory

- ``malloc`` - Obtain information on C Program Heap

Commands
========

This section details the Memory Commands available.  A
subsection is dedicated to each of the commands and
describes the behavior and configuration of that
command as well as providing an example usage.

mdump - display contents of memory
----------------------------------
.. index:: mdump

**SYNOPSYS:**

.. code:: c

    mdump \[address \[length \[size]]]

**DESCRIPTION:**

This command displays the contents of memory at the ``address``
and ``length`` in ``size`` byte units specified on the command line.

When ``size`` is not provided, it defaults to ``1`` byte units.
Values of ``1``, ``2``, and ``4`` are valid; all others will
cause an error to be reported.

When ``length`` is not provided, it defaults to ``320`` which
is twenty lines of output with sixteen bytes of output per line.

When ``address`` is not provided, it defaults to ``0x00000000``.

**EXIT STATUS:**

This command always returns 0 to indicate success.

**NOTES:**

Dumping memory from a non-existent address may result in an unrecoverable
program fault.

**EXAMPLES:**

The following is an example of how to use ``mdump``:
.. code:: c

    SHLL \[/] $ mdump 0x10000 32
    0x0001000000 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
    0x0001001000 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
    SHLL \[/] $ mdump 0x02000000 32
    0x02000000A1 48 00 00 29 00 80 33-81 C5 22 BC A6 10 21 00 .H..)..3.."...!.
    0x02000010A1 48 00 00 29 00 80 33-81 C5 22 BC A6 10 21 01 .H..)..3.."...!.
    SHLL \[/] $ mdump 0x02001000 32
    0x0200100003 00 80 00 82 10 60 00-81 98 40 00 83 48 00 00 ......`.....H..
    0x0200101084 00 60 01 84 08 A0 07-86 10 20 01 87 28 C0 02 ..`....... ..(..

**CONFIGURATION:**

.. index:: CONFIGURE_SHELL_NO_COMMAND_MDUMP
.. index:: CONFIGURE_SHELL_COMMAND_MDUMP

This command is included in the default shell command set.
When building a custom command set, define``CONFIGURE_SHELL_COMMAND_MDUMP`` to have this
command included.

This command can be excluded from the shell command set by
defining ``CONFIGURE_SHELL_NO_COMMAND_MDUMP`` when all
shell commands have been configured.

**PROGRAMMING INFORMATION:**

.. index:: rtems_shell_rtems_main_mdump

The ``mdump`` is implemented by a C language function
which has the following prototype:
.. code:: c

    int rtems_shell_rtems_main_mdump(
    int    argc,
    char \**argv
    );

The configuration structure for the ``mdump`` has the
following prototype:
.. code:: c

    extern rtems_shell_cmd_t rtems_shell_MDUMP_Command;

wdump - display contents of memory (word)
-----------------------------------------
.. index:: wdump

**SYNOPSYS:**

.. code:: c

    wdump \[address \[length]]

**DESCRIPTION:**

This command displays the contents of memory at the ``address``
and ``length`` in bytes specified on the command line.

This command is equivalent to ``mdump address length 2``.

When ``length`` is not provided, it defaults to ``320`` which
is twenty lines of output with eight words of output per line.

When ``address`` is not provided, it defaults to ``0x00000000``.

**EXIT STATUS:**

This command always returns 0 to indicate success.

**NOTES:**

Dumping memory from a non-existent address may result in an unrecoverable
program fault.

**EXAMPLES:**

The following is an example of how to use ``wdump``:
.. code:: c

    SHLL \[/] $ wdump 0x02010000 32
    0x02010000 0201 08D8 0201 08C0-0201 08AC 0201 0874 ...............t
    0x02010010 0201 0894 0201 0718-0201 0640 0201 0798 ...............

**CONFIGURATION:**

.. index:: CONFIGURE_SHELL_NO_COMMAND_WDUMP
.. index:: CONFIGURE_SHELL_COMMAND_WDUMP

This command is included in the default shell command set.
When building a custom command set, define``CONFIGURE_SHELL_COMMAND_WDUMP`` to have this
command included.

This command can be excluded from the shell command set by
defining ``CONFIGURE_SHELL_NO_COMMAND_WDUMP`` when all
shell commands have been configured.

**PROGRAMMING INFORMATION:**

.. index:: rtems_shell_rtems_main_wdump

The ``wdump`` is implemented by a C language function
which has the following prototype:
.. code:: c

    int rtems_shell_rtems_main_wdump(
    int    argc,
    char \**argv
    );

The configuration structure for the ``wdump`` has the
following prototype:
.. code:: c

    extern rtems_shell_cmd_t rtems_shell_WDUMP_Command;

ldump - display contents of memory (longword)
---------------------------------------------
.. index:: ldump

**SYNOPSYS:**

.. code:: c

    ldump \[address \[length]]

**DESCRIPTION:**

This command displays the contents of memory at the ``address``
and ``length`` in bytes specified on the command line.

This command is equivalent to ``mdump address length 4``.

When ``length`` is not provided, it defaults to ``320`` which
is twenty lines of output with four longwords of output per line.

When ``address`` is not provided, it defaults to ``0x00000000``.

**EXIT STATUS:**

This command always returns 0 to indicate success.

**NOTES:**

Dumping memory from a non-existent address may result in an unrecoverable
program fault.

**EXAMPLES:**

The following is an example of how to use ``ldump``:
.. code:: c

    SHLL \[/] $ ldump 0x02010000 32
    0x02010000 020108D8 020108C0-020108AC 02010874 ...............t
    0x02010010 020 0894 02010718-02010640 02010798 ...............

**CONFIGURATION:**

.. index:: CONFIGURE_SHELL_NO_COMMAND_LDUMP
.. index:: CONFIGURE_SHELL_COMMAND_LDUMP

This command is included in the default shell command set.
When building a custom command set, define``CONFIGURE_SHELL_COMMAND_LDUMP`` to have this
command included.

This command can be excluded from the shell command set by
defining ``CONFIGURE_SHELL_NO_COMMAND_LDUMP`` when all
shell commands have been configured.

**PROGRAMMING INFORMATION:**

.. index:: rtems_shell_rtems_main_ldump

The ``ldump`` is implemented by a C language function
which has the following prototype:
.. code:: c

    int rtems_shell_rtems_main_ldump(
    int    argc,
    char \**argv
    );

The configuration structure for the ``ldump`` has the
following prototype:
.. code:: c

    extern rtems_shell_cmd_t rtems_shell_LDUMP_Command;

medit - modify contents of memory
---------------------------------
.. index:: medit

**SYNOPSYS:**

.. code:: c

    medit address value1 \[value2 ... valueN]

**DESCRIPTION:**

This command is used to modify the contents of the memory starting
at ``address`` using the octets specified by the parameters``value1`` through ``valueN``.

**EXIT STATUS:**

This command returns 0 on success and non-zero if an error is encountered.

**NOTES:**

Dumping memory from a non-existent address may result in an unrecoverable
program fault.

**EXAMPLES:**

The following is an example of how to use ``medit``:
.. code:: c

    SHLL \[/] $ mdump 0x02000000 32
    0x02000000 A1 48 00 00 29 00 80 33-81 C5 22 BC A6 10 21 00 .H..)..3.."...!.
    0x02000010 A1 48 00 00 29 00 80 33-81 C5 22 BC A6 10 21 01 .H..)..3.."...!.
    SHLL \[/] $  medit 0x02000000 0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08 0x09
    SHLL \[/] $ mdump 0x02000000 32
    0x02000000 01 02 03 04 05 06 07 08-09 00 22 BC A6 10 21 00 .........."...!.
    0x02000010 A1 48 00 00 29 00 80 33-81 C5 22 BC A6 10 21 01 .H..)..3.."...!.

**CONFIGURATION:**

.. index:: CONFIGURE_SHELL_NO_COMMAND_MEDIT
.. index:: CONFIGURE_SHELL_COMMAND_MEDIT

This command is included in the default shell command set.
When building a custom command set, define``CONFIGURE_SHELL_COMMAND_MEDIT`` to have this
command included.

This command can be excluded from the shell command set by
defining ``CONFIGURE_SHELL_NO_COMMAND_MEDIT`` when all
shell commands have been configured.

**PROGRAMMING INFORMATION:**

.. index:: rtems_shell_rtems_main_medit

The ``medit`` is implemented by a C language function
which has the following prototype:
.. code:: c

    int rtems_shell_rtems_main_medit(
    int    argc,
    char \**argv
    );

The configuration structure for the ``medit`` has the
following prototype:
.. code:: c

    extern rtems_shell_cmd_t rtems_shell_MEDIT_Command;

mfill - file memory with pattern
--------------------------------
.. index:: mfill

**SYNOPSYS:**

.. code:: c

    mfill address length value

**DESCRIPTION:**

This command is used to fill the memory starting at ``address``
for the specified ``length`` in octets when the specified at``value``.

**EXIT STATUS:**

This command returns 0 on success and non-zero if an error is encountered.

**NOTES:**

Filling a non-existent address range may result in an unrecoverable
program fault.  Similarly overwriting interrupt vector tables, code
space or critical data areas can be fatal as shown in the example.

**EXAMPLES:**

In this example, the address used (``0x23d89a0``) as the base
address of the filled area is the end of the stack for the
Idle thread.  This address was determined manually using gdb and
is very specific to this application and BSP.  The first command
in this example is an ``mdump`` to display the initial contents
of this memory.  We see that the first 8 bytes are 0xA5 which is
the pattern used as a guard by the Stack Checker.  On
the first context switch after the pattern is overwritten
by the  ``mfill`` command, the Stack Checker detect the pattern
has been corrupted and generates a fatal error.
.. code:: c

    SHLL \[/] $ mdump 0x23d89a0 16
    0x023D89A0 A5 A5 A5 A5 A5 A5 A5 A5-FE ED F0 0D 0B AD 0D 06 ................
    SHLL \[/] $ mfill 0x23d89a0 13 0x5a
    SHLL \[/] $ BLOWN STACK!!! Offending task(0x23D4418): id=0x09010001; name=0x0203D908
    stack covers range 0x23D89A0 - 0x23D99AF (4112 bytes)
    Damaged pattern begins at 0x023D89A8 and is 16 bytes long

**CONFIGURATION:**

.. index:: CONFIGURE_SHELL_NO_COMMAND_MFILL
.. index:: CONFIGURE_SHELL_COMMAND_MFILL

This command is included in the default shell command set.
When building a custom command set, define``CONFIGURE_SHELL_COMMAND_MFILL`` to have this
command included.

This command can be excluded from the shell command set by
defining ``CONFIGURE_SHELL_NO_COMMAND_MFILL`` when all
shell commands have been configured.

**PROGRAMMING INFORMATION:**

.. index:: rtems_shell_rtems_main_mfill

The ``mfill`` is implemented by a C language function
which has the following prototype:
.. code:: c

    int rtems_shell_rtems_main_mfill(
    int    argc,
    char \**argv
    );

The configuration structure for the ``mfill`` has the
following prototype:
.. code:: c

    extern rtems_shell_cmd_t rtems_shell_MFILL_Command;

mmove - move contents of memory
-------------------------------
.. index:: mmove

**SYNOPSYS:**

.. code:: c

    mmove dst src length

**DESCRIPTION:**

This command is used to copy the contents of the memory
starting at ``src`` to the memory located at ``dst``
for the specified ``length`` in octets.

**EXIT STATUS:**

This command returns 0 on success and non-zero if an error is encountered.

**NOTES:**

NONE

**EXAMPLES:**

The following is an example of how to use ``mmove``:
.. code:: c

    SHLL \[/] $ mdump 0x023d99a0 16
    0x023D99A0 A5 A5 A5 A5 A5 A5 A5 A5-A5 A5 A5 A5 A5 A5 A5 A5 ................
    SHLL \[/] $ mdump 0x02000000 16
    0x02000000 A1 48 00 00 29 00 80 33-81 C5 22 BC A6 10 21 00 .H..)..3.."...!.
    SHLL \[/] $ mmove 0x023d99a0 0x02000000 13
    SHLL \[/] $ mdump 0x023d99a0 16
    0x023D99A0 A1 48 00 00 29 00 80 33-81 C5 22 BC A6 A5 A5 A5 .H..)..3..".....

**CONFIGURATION:**

.. index:: CONFIGURE_SHELL_NO_COMMAND_MMOVE
.. index:: CONFIGURE_SHELL_COMMAND_MMOVE

This command is included in the default shell command set.
When building a custom command set, define``CONFIGURE_SHELL_COMMAND_MMOVE`` to have this
command included.

This command can be excluded from the shell command set by
defining ``CONFIGURE_SHELL_NO_COMMAND_MMOVE`` when all
shell commands have been configured.

**PROGRAMMING INFORMATION:**

.. index:: rtems_shell_rtems_main_mmove

The ``mmove`` is implemented by a C language function
which has the following prototype:
.. code:: c

    int rtems_shell_rtems_main_mmove(
    int    argc,
    char \**argv
    );

The configuration structure for the ``mmove`` has the
following prototype:
.. code:: c

    extern rtems_shell_cmd_t rtems_shell_MMOVE_Command;

malloc - obtain information on C program heap
---------------------------------------------
.. index:: malloc

**SYNOPSYS:**

.. code:: c

    malloc \[walk]

**DESCRIPTION:**

This command prints information about the current state of the C Program Heap
used by the ``malloc()`` family of calls if no or invalid options are passed
to the command.  This includes the following information:

- Number of free blocks

- Largest free block

- Total bytes free

- Number of used blocks

- Largest used block

- Total bytes used

- Size of the allocatable area in bytes

- Minimum free size ever in bytes

- Maximum number of free blocks ever

- Maximum number of blocks searched ever

- Lifetime number of bytes allocated

- Lifetime number of bytes freed

- Total number of searches

- Total number of successful allocations

- Total number of failed allocations

- Total number of successful frees

- Total number of successful resizes

When the subcommand ``walk`` is specified, then a heap walk will be
performed and information about each block is printed out.

**EXIT STATUS:**

This command returns 0 on success and non-zero if an error is encountered.

**NOTES:**

NONE

**EXAMPLES:**

The following is an example of how to use the ``malloc`` command.
.. code:: c

    SHLL \[/] $ malloc
    C Program Heap and RTEMS Workspace are the same.
    Number of free blocks:                               2
    Largest free block:                          266207504
    Total bytes free:                            266208392
    Number of used blocks:                             167
    Largest used block:                              16392
    Total bytes used:                                83536
    Size of the allocatable area in bytes:       266291928
    Minimum free size ever in bytes:             266207360
    Maximum number of free blocks ever:                  6
    Maximum number of blocks searched ever:              5
    Lifetime number of bytes allocated:              91760
    Lifetime number of bytes freed:                   8224
    Total number of searches:                          234
    Total number of successful allocations:            186
    Total number of failed allocations:                  0
    Total number of successful frees:                   19
    Total number of successful resizes:                  0
    SHLL \[/] $ malloc walk
    malloc walk
    PASS[0]: page size 8, min block size 48
    area begin 0x00210210, area end 0x0FFFC000
    first block 0x00210214, last block 0x0FFFBFDC
    first free 0x00228084, last free 0x00228354
    PASS[0]: block 0x00210214: size 88
    ...
    PASS[0]: block 0x00220154: size 144
    PASS[0]: block 0x002201E4: size 168, prev 0x002205BC, next 0x00228354 (= last free)
    PASS[0]: block 0x0022028C: size 168, prev_size 168
    ...
    PASS[0]: block 0x00226E7C: size 4136
    PASS[0]: block 0x00227EA4: size 408, prev 0x00228084 (= first free), next 0x00226CE4
    PASS[0]: block 0x0022803C: size 72, prev_size 408
    PASS[0]: block 0x00228084: size 648, prev 0x0020F75C (= head), next 0x00227EA4
    PASS[0]: block 0x0022830C: size 72, prev_size 648
    PASS[0]: block 0x00228354: size 266157192, prev 0x002201E4, next 0x0020F75C (= tail)
    PASS[0]: block 0x0FFFBFDC: size 4028711480, prev_size 266157192

**CONFIGURATION:**

.. index:: CONFIGURE_SHELL_NO_COMMAND_MALLOC
.. index:: CONFIGURE_SHELL_COMMAND_MALLOC

This command is included in the default shell command set.
When building a custom command set, define``CONFIGURE_SHELL_COMMAND_MALLOC`` to have this
command included.

This command can be excluded from the shell command set by
defining ``CONFIGURE_SHELL_NO_COMMAND_MALLOC`` when all
shell commands have been configured.

**PROGRAMMING INFORMATION:**

.. index:: rtems_shell_rtems_main_malloc

The ``malloc`` is implemented by a C language function
which has the following prototype:
.. code:: c

    int rtems_shell_rtems_main_malloc(
    int    argc,
    char \**argv
    );

The configuration structure for the ``malloc`` has the
following prototype:
.. code:: c

    extern rtems_shell_cmd_t rtems_shell_MALLOC_Command;

.. COMMENT: COPYRIGHT (c) 1988-2008.

.. COMMENT: On-Line Applications Research Corporation (OAR).

.. COMMENT: All rights reserved.