cmd: Introduce CMD_HELP

Add option to disable help command in size constrained systems to save some
space. There is also no need to have ifdefs around CMDLINE because all
commands depends on it.
And also mark cmd_help dependency in test_help.py.

Reviewed-by: Peter Robinson <pbrobinson@gmail.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@kernel.org>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/c17f825fb8a74e1d1912a3fd09a9a880c84a8bfd.1751286059.git.michal.simek@amd.com

cmd/Kconfig

@@ -190,6 +190,12 @@ config CMD_FWU_METADATA
 	help
 	  Command to read the metadata and dump it's contents
 
+config CMD_HELP
+	bool "help"
+	default y
+	help
+	  Command to show help information about other commands.
+
 config CMD_HISTORY
 	bool "history"
 	depends on CMDLINE_EDITING

cmd/Makefile

@@ -7,7 +7,7 @@ ifndef CONFIG_XPL_BUILD
 # core command
 obj-y += boot.o
 obj-$(CONFIG_CMD_BOOTM) += bootm.o
-obj-y += help.o
+obj-$(CONFIG_CMD_HELP) += help.o
 obj-y += panic.o
 obj-y += version.o
 

cmd/help.c

@@ -9,13 +9,9 @@
 static int do_help(struct cmd_tbl *cmdtp, int flag, int argc,
 		   char *const argv[])
 {
-#ifdef CONFIG_CMDLINE
 	struct cmd_tbl *start = ll_entry_start(struct cmd_tbl, cmd);
 	const int len = ll_entry_count(struct cmd_tbl, cmd);
 	return _do_help(start, len, cmdtp, flag, argc, argv);
-#else
-	return 0;
-#endif
 }
 
 U_BOOT_CMD(
@@ -27,7 +23,6 @@ U_BOOT_CMD(
 	"	- print detailed usage of 'command'"
 );
 
-#ifdef CONFIG_CMDLINE
 /*
  * This does not use the U_BOOT_CMD macro as ? can't be used in symbol names
  * nor can we rely on the CONFIG_SYS_LONGHELP helper macro
@@ -39,4 +34,3 @@ ll_entry_declare(struct cmd_tbl, question_mark, cmd) = {
 	""
 #endif /* CONFIG_SYS_LONGHELP */
 };
-#endif

test/py/tests/test_help.py

@@ -4,6 +4,7 @@
 
 import pytest
 
+@pytest.mark.buildconfigspec('cmd_help')
 def test_help(ubman):
     """Test that the "help" command can be executed."""