doc: move README.commands to HTML doc

Reformat README.commands as reStructured text and add it to the HTML
documentation as develop/commands.rst.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

3 files changed, 227 insertions, 186 deletions

diff --git a/doc/README.commands b/doc/README.commands
deleted file mode 100644
index 22ab063fdc0..00000000000
--- a/doc/README.commands
+++ /dev/null
@@ -1,186 +0,0 @@
-Command definition
-------------------
-
-Commands are added to U-Boot by creating a new command structure.
-This is done by first including command.h, then using the U_BOOT_CMD() or the
-U_BOOT_CMD_COMPLETE macro to fill in a struct cmd_tbl struct.
-
-U_BOOT_CMD(name, maxargs, repeatable, command, "usage", "help")
-U_BOOT_CMD_COMPLETE(name, maxargs, repeatable, command, "usage, "help", comp)
-
-name:		The name of the command. THIS IS NOT a string.
-
-maxargs:	The maximum number of arguments this function takes including
-		the command itself.
-
-repeatable:	Either 0 or 1 to indicate if autorepeat is allowed.
-
-command:	Pointer to the command function. This is the function that is
-		called when the command is issued.
-
-usage:		Short description. This is a string.
-
-help:		Long description. This is a string. The long description is
-		only available if CONFIG_SYS_LONGHELP is defined.
-
-comp:		Pointer to the completion function. May be NULL.
-		This function is called if the user hits the TAB key while
-		entering the command arguments to complete the entry. Command
-		completion is only available if CONFIG_AUTO_COMPLETE is defined.
-
-Sub-command definition
-----------------------
-
-Likewise an array of struct cmd_tbl holding sub-commands can be created using either
-of the following macros:
-
-* U_BOOT_CMD_MKENT(name, maxargs, repeatable, command, "usage", "help")
-* U_BOOT_CMD_MKENTCOMPLETE(name, maxargs, repeatable, command, "usage, "help",
-  comp)
-
-This table has to be evaluated in the command function of the main command, e.g.
-
-    static struct cmd_tbl cmd_sub[] = {
-        U_BOOT_CMD_MKENT(foo, CONFIG_SYS_MAXARGS, 1, do_foo, "", ""),
-        U_BOOT_CMD_MKENT(bar, CONFIG_SYS_MAXARGS, 1, do_bar, "", ""),
-    };
-
-    static int do_cmd(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
-    {
-        struct cmd_tbl *cp;
-
-        if (argc < 2)
-                return CMD_RET_USAGE;
-
-        /* drop sub-command argument */
-        argc--;
-        argv++;
-
-        cp = find_cmd_tbl(argv[0], cmd_ut_sub, ARRAY_SIZE(cmd_sub));
-
-        if (cp)
-            return cp->cmd(cmdtp, flag, argc, argv);
-
-        return CMD_RET_USAGE;
-    }
-
-Command function
-----------------
-
-The command function pointer has to be of type
-int (*cmd)(struct cmd_tbl *cmdtp, int flag, int argc, const char *argv[]);
-
-cmdtp:		Table entry describing the command (see above).
-
-flag:		A bitmap which may contain the following bit:
-		CMD_FLAG_REPEAT - The last command is repeated.
-		CMD_FLAG_BOOTD  - The command is called by the bootd command.
-		CMD_FLAG_ENV    - The command is called by the run command.
-
-argc:		Number of arguments including the command.
-
-argv:		Arguments.
-
-Allowable return value are:
-
-CMD_RET_SUCCESS	The command was successfully executed.
-
-CMD_RET_FAILURE	The command failed.
-
-CMD_RET_USAGE	The command was called with invalid parameters. This value
-		leads to the display of the usage string.
-
-Completion function
--------------------
-
-The completion function pointer has to be of type
-int (*complete)(int argc, char *const argv[], char last_char,
-		int maxv, char *cmdv[]);
-
-argc:		Number of arguments including the command.
-
-argv:		Arguments.
-
-last_char:	The last character in the command line buffer.
-
-maxv:		Maximum number of possible completions that may be returned by
-		the function.
-
-cmdv:		Used to return possible values for the last argument. The last
-		possible completion must be followed by NULL.
-
-The function returns the number of possible completions (without the terminating
-NULL value).
-
-Behind the scene
-----------------
-
-The structure created is named with a special prefix and placed by
-the linker in a special section using the linker lists mechanism
-(see include/linker_lists.h)
-
-This makes it possible for the final link to extract all commands
-compiled into any object code and construct a static array so the
-command array can be iterated over using the linker lists macros.
-
-The linker lists feature ensures that the linker does not discard
-these symbols when linking full U-Boot even though they are not
-referenced in the source code as such.
-
-If a new board is defined do not forget to define the command section
-by writing in u-boot.lds ($(srctree)/board/boardname/u-boot.lds) these
-3 lines:
-
-	.u_boot_list : {
-		KEEP(*(SORT(.u_boot_list*)));
-	}
-
-Writing tests
--------------
-
-All new commands should have tests. Tests for existing commands are very
-welcome.
-
-It is fairly easy to write a test for a command. Enable it in sandbox, and
-then add code that runs the command and checks the output.
-
-Here is an example:
-
-/* Test 'acpi items' command */
-static int dm_test_acpi_cmd_items(struct unit_test_state *uts)
-{
-	struct acpi_ctx ctx;
-	void *buf;
-
-	buf = malloc(BUF_SIZE);
-	ut_assertnonnull(buf);
-
-	ctx.current = buf;
-	ut_assertok(acpi_fill_ssdt(&ctx));
-	console_record_reset();
-	run_command("acpi items", 0);
-	ut_assert_nextline("dev 'acpi-test', type 1, size 2");
-	ut_assert_nextline("dev 'acpi-test2', type 1, size 2");
-	ut_assert_console_end();
-
-	ctx.current = buf;
-	ut_assertok(acpi_inject_dsdt(&ctx));
-	console_record_reset();
-	run_command("acpi items", 0);
-	ut_assert_nextline("dev 'acpi-test', type 2, size 2");
-	ut_assert_nextline("dev 'acpi-test2', type 2, size 2");
-	ut_assert_console_end();
-
-	console_record_reset();
-	run_command("acpi items -d", 0);
-	ut_assert_nextline("dev 'acpi-test', type 2, size 2");
-	ut_assert_nextlines_are_dump(2);
-	ut_assert_nextline("%s", "");
-	ut_assert_nextline("dev 'acpi-test2', type 2, size 2");
-	ut_assert_nextlines_are_dump(2);
-	ut_assert_nextline("%s", "");
-	ut_assert_console_end();
-
-	return 0;
-}
-DM_TEST(dm_test_acpi_cmd_items, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
diff --git a/doc/develop/commands.rst b/doc/develop/commands.rst
new file mode 100644
index 00000000000..c72d1b0aaad
--- /dev/null
+++ b/doc/develop/commands.rst
@@ -0,0 +1,226 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+Implementing shell commands
+===========================
+
+Command definition
+------------------
+
+Commands are added to U-Boot by creating a new command structure.
+This is done by first including command.h, then using the U_BOOT_CMD() or the
+U_BOOT_CMD_COMPLETE macro to fill in a struct cmd_tbl structure.
+
+.. code-block:: c
+
+    U_BOOT_CMD(name, maxargs, repeatable, command, "usage", "help")
+    U_BOOT_CMD_COMPLETE(name, maxargs, repeatable, command, "usage, "help", comp)
+
+name
+    The name of the command. This is **not** a string.
+
+maxargs
+    The maximum number of arguments this function takes including
+    the command itself.
+
+repeatable
+    Either 0 or 1 to indicate if autorepeat is allowed.
+
+command
+    Pointer to the command function. This is the function that is
+    called when the command is issued.
+
+usage
+    Short description. This is a string.
+
+help
+    Long description. This is a string. The long description is
+    only available if CONFIG_SYS_LONGHELP is defined.
+
+comp
+    Pointer to the completion function. May be NULL.
+    This function is called if the user hits the TAB key while
+    entering the command arguments to complete the entry. Command
+    completion is only available if CONFIG_AUTO_COMPLETE is defined.
+
+Sub-command definition
+----------------------
+
+Likewise an array of struct cmd_tbl holding sub-commands can be created using
+either of the following macros:
+
+.. code-block:: c
+
+    U_BOOT_CMD_MKENT(name, maxargs, repeatable, command, "usage", "help")
+    U_BOOT_CMD_MKENTCOMPLETE(name, maxargs, repeatable, command, "usage, "help", comp)
+
+This table has to be evaluated in the command function of the main command, e.g.
+
+.. code-block:: c
+
+    static struct cmd_tbl cmd_sub[] = {
+        U_BOOT_CMD_MKENT(foo, CONFIG_SYS_MAXARGS, 1, do_foo, "", ""),
+        U_BOOT_CMD_MKENT(bar, CONFIG_SYS_MAXARGS, 1, do_bar, "", ""),
+    };
+
+    static int do_cmd(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
+    {
+        struct cmd_tbl *cp;
+
+        if (argc < 2)
+                return CMD_RET_USAGE;
+
+        /* drop sub-command argument */
+        argc--;
+        argv++;
+
+        cp = find_cmd_tbl(argv[0], cmd_ut_sub, ARRAY_SIZE(cmd_sub));
+
+        if (cp)
+            return cp->cmd(cmdtp, flag, argc, argv);
+
+        return CMD_RET_USAGE;
+    }
+
+Command function
+----------------
+
+The command function pointer has to be of type
+
+.. code-block:: c
+
+    int (*cmd)(struct cmd_tbl *cmdtp, int flag, int argc, const char *argv[]);
+
+cmdtp
+    Table entry describing the command (see above).
+
+flag
+    A bitmap which may contain the following bits
+
+    * CMD_FLAG_REPEAT - The last command is repeated.
+    * CMD_FLAG_BOOTD  - The command is called by the bootd command.
+    * CMD_FLAG_ENV    - The command is called by the run command.
+
+argc
+    Number of arguments including the command.
+
+argv
+    Arguments.
+
+Allowable return value are:
+
+CMD_RET_SUCCESS
+    The command was successfully executed.
+
+CMD_RET_FAILURE
+    The command failed.
+
+CMD_RET_USAGE
+    The command was called with invalid parameters. This value
+    leads to the display of the usage string.
+
+Completion function
+-------------------
+
+The completion function pointer has to be of type
+
+.. code-block:: c
+
+    int (*complete)(int argc, char *const argv[], char last_char,
+                    int maxv, char *cmdv[]);
+
+argc
+    Number of arguments including the command.
+
+argv
+    Arguments.
+
+last_char
+    The last character in the command line buffer.
+
+maxv
+    Maximum number of possible completions that may be returned by
+    the function.
+
+cmdv
+    Used to return possible values for the last argument. The last
+    possible completion must be followed by NULL.
+
+The function returns the number of possible completions (without the terminating
+NULL value).
+
+Behind the scene
+----------------
+
+The structure created is named with a special prefix and placed by
+the linker in a special section using the linker lists mechanism
+(see include/linker_lists.h)
+
+This makes it possible for the final link to extract all commands
+compiled into any object code and construct a static array so the
+command array can be iterated over using the linker lists macros.
+
+The linker lists feature ensures that the linker does not discard
+these symbols when linking full U-Boot even though they are not
+referenced in the source code as such.
+
+If a new board is defined do not forget to define the command section
+by writing in u-boot.lds ($(srctree)/board/boardname/u-boot.lds) these
+3 lines:
+
+.. code-block:: c
+
+    .u_boot_list : {
+        KEEP(*(SORT(.u_boot_list*)));
+    }
+
+Writing tests
+-------------
+
+All new commands should have tests. Tests for existing commands are very
+welcome.
+
+It is fairly easy to write a test for a command. Enable it in sandbox, and
+then add code that runs the command and checks the output.
+
+Here is an example:
+
+.. code-block:: c
+
+    /* Test 'acpi items' command */
+    static int dm_test_acpi_cmd_items(struct unit_test_state *uts)
+    {
+        struct acpi_ctx ctx;
+        void *buf;
+
+        buf = malloc(BUF_SIZE);
+        ut_assertnonnull(buf);
+
+        ctx.current = buf;
+        ut_assertok(acpi_fill_ssdt(&ctx));
+        console_record_reset();
+        run_command("acpi items", 0);
+        ut_assert_nextline("dev 'acpi-test', type 1, size 2");
+        ut_assert_nextline("dev 'acpi-test2', type 1, size 2");
+        ut_assert_console_end();
+
+        ctx.current = buf;
+        ut_assertok(acpi_inject_dsdt(&ctx));
+        console_record_reset();
+        run_command("acpi items", 0);
+        ut_assert_nextline("dev 'acpi-test', type 2, size 2");
+        ut_assert_nextline("dev 'acpi-test2', type 2, size 2");
+        ut_assert_console_end();
+
+        console_record_reset();
+        run_command("acpi items -d", 0);
+        ut_assert_nextline("dev 'acpi-test', type 2, size 2");
+        ut_assert_nextlines_are_dump(2);
+        ut_assert_nextline("%s", "");
+        ut_assert_nextline("dev 'acpi-test2', type 2, size 2");
+        ut_assert_nextlines_are_dump(2);
+        ut_assert_nextline("%s", "");
+        ut_assert_console_end();
+
+        return 0;
+    }
+    DM_TEST(dm_test_acpi_cmd_items, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
diff --git a/doc/develop/index.rst b/doc/develop/index.rst
index 89e80eab945..c95a8d6b123 100644
--- a/doc/develop/index.rst
+++ b/doc/develop/index.rst
@@ -8,6 +8,7 @@ Develop U-Boot
    :maxdepth: 2
 
    coccinelle
+   commands
    crash_dumps
    global_data
    logging