bootm: Allow updating the bootargs in a buffer

At present we only support updating the 'bootargs' environment
variable. Add another function to update a buffer instead. This will
allow zimage to use this feature.

Also add a lot more tests to cover various cases.

Signed-off-by: Simon Glass <sjg@chromium.org>

common/bootm.c

@@ -542,6 +542,22 @@ static int fixup_silent_linux(char *buf, int maxlen)
 	return 0;
 }
 
+int bootm_process_cmdline(char *buf, int maxlen, int flags)
+{
+	int ret;
+
+	/* Check config first to enable compiler to eliminate code */
+	if (IS_ENABLED(CONFIG_SILENT_CONSOLE) &&
+	    !IS_ENABLED(CONFIG_SILENT_U_BOOT_ONLY) &&
+	    (flags & BOOTM_CL_SILENT)) {
+		ret = fixup_silent_linux(buf, maxlen);
+		if (ret)
+			return log_msg_ret("silent", ret);
+	}
+
+	return 0;
+}
+
 int bootm_process_cmdline_env(int flags)
 {
 	const int maxlen = MAX_CMDLINE_SIZE;
@@ -566,7 +582,7 @@ int bootm_process_cmdline_env(int flags)
 		strcpy(buf, env);
 	else
 		*buf = '\0';
-	ret = fixup_silent_linux(buf, maxlen);
+	ret = bootm_process_cmdline(buf, maxlen, flags);
 	if (!ret) {
 		ret = env_set("bootargs", buf);
 

include/bootm.h

@@ -93,6 +93,22 @@ void arch_preboot_os(void);
 void board_preboot_os(void);
 
 /*
+ * bootm_process_cmdline() - Process fix-ups for the command line
+ *
+ * This handles: making Linux boot silently if requested ('silent_linux' envvar)
+ *
+ * @maxlen must provide enough space for the string being processed plus the
+ * resulting string
+ *
+ * @buf: buffer holding commandline string to adjust
+ * @maxlen: Maximum length of buffer at @buf (including \0)
+ * @flags: Flags to control what happens (see bootm_cmdline_t)
+ * @return 0 if OK, -ENOMEM if out of memory, -ENOSPC if the commandline is too
+ *	long
+ */
+int bootm_process_cmdline(char *buf, int maxlen, int flags);
+
+/**
  * bootm_process_cmdline_env() - Process fix-ups for the command line
  *
  * Updates the 'bootargs' envvar as required. This handles making Linux boot

test/bootm.c

@@ -15,33 +15,117 @@ DECLARE_GLOBAL_DATA_PTR;
 
 #define BOOTM_TEST(_name, _flags)	UNIT_TEST(_name, _flags, bootm_test)
 
+enum {
+	BUF_SIZE	= 1024,
+};
+
 #define CONSOLE_STR	"console=/dev/ttyS0"
 
+/* Test cmdline processing where nothing happens */
+static int bootm_test_nop(struct unit_test_state *uts)
+{
+	char buf[BUF_SIZE];
+
+	*buf = '\0';
+	ut_assertok(bootm_process_cmdline(buf, BUF_SIZE, true));
+	ut_asserteq_str("", buf);
+
+	strcpy(buf, "test");
+	ut_assertok(bootm_process_cmdline(buf, BUF_SIZE, true));
+	ut_asserteq_str("test", buf);
+
+	return 0;
+}
+BOOTM_TEST(bootm_test_nop, 0);
+
+/* Test cmdline processing when out of space */
+static int bootm_test_nospace(struct unit_test_state *uts)
+{
+	char buf[BUF_SIZE];
+
+	/* Zero buffer size */
+	*buf = '\0';
+	ut_asserteq(-ENOSPC, bootm_process_cmdline(buf, 0, true));
+
+	/* Buffer string not terminated */
+	memset(buf, 'a', BUF_SIZE);
+	ut_asserteq(-ENOSPC, bootm_process_cmdline(buf, BUF_SIZE, true));
+
+	/* Not enough space to copy string */
+	memset(buf, '\0', BUF_SIZE);
+	memset(buf, 'a', BUF_SIZE / 2);
+	ut_asserteq(-ENOSPC, bootm_process_cmdline(buf, BUF_SIZE, true));
+
+	/* Just enough space */
+	memset(buf, '\0', BUF_SIZE);
+	memset(buf, 'a', BUF_SIZE / 2 - 1);
+	ut_assertok(bootm_process_cmdline(buf, BUF_SIZE, true));
+
+	return 0;
+}
+BOOTM_TEST(bootm_test_nospace, 0);
+
+/* Test silent processing */
+static int bootm_test_silent(struct unit_test_state *uts)
+{
+	char buf[BUF_SIZE];
+
+	/* 'silent_linux' not set should do nothing */
+	env_set("silent_linux", NULL);
+	strcpy(buf, CONSOLE_STR);
+	ut_assertok(bootm_process_cmdline(buf, BUF_SIZE, BOOTM_CL_SILENT));
+	ut_asserteq_str(CONSOLE_STR, buf);
+
+	ut_assertok(env_set("silent_linux", "no"));
+	ut_assertok(bootm_process_cmdline(buf, BUF_SIZE, BOOTM_CL_SILENT));
+	ut_asserteq_str(CONSOLE_STR, buf);
+
+	ut_assertok(env_set("silent_linux", "yes"));
+	ut_assertok(bootm_process_cmdline(buf, BUF_SIZE, BOOTM_CL_SILENT));
+	ut_asserteq_str("console=", buf);
+
+	/* Empty buffer should still add the string */
+	*buf = '\0';
+	ut_assertok(bootm_process_cmdline(buf, BUF_SIZE, BOOTM_CL_SILENT));
+	ut_asserteq_str("console=", buf);
+
+	/* Check nothing happens when do_silent is false */
+	*buf = '\0';
+	ut_assertok(bootm_process_cmdline(buf, BUF_SIZE, 0));
+	ut_asserteq_str("", buf);
+
+	/* Not enough space */
+	*buf = '\0';
+	ut_asserteq(-ENOSPC, bootm_process_cmdline(buf, 8, BOOTM_CL_SILENT));
+
+	/* Just enough space */
+	*buf = '\0';
+	ut_assertok(bootm_process_cmdline(buf, 9, BOOTM_CL_SILENT));
+
+	/* add at end */
+	strcpy(buf, "something");
+	ut_assertok(bootm_process_cmdline(buf, BUF_SIZE, BOOTM_CL_SILENT));
+	ut_asserteq_str("something console=", buf);
+
+	/* change at start */
+	strcpy(buf, CONSOLE_STR " something");
+	ut_assertok(bootm_process_cmdline(buf, BUF_SIZE, BOOTM_CL_SILENT));
+	ut_asserteq_str("console= something", buf);
+
+	return 0;
+}
+BOOTM_TEST(bootm_test_silent, 0);
+
 /* Test silent processing in the bootargs variable */
 static int bootm_test_silent_var(struct unit_test_state *uts)
 {
-	/* 'silent_linux' not set should do nothing */
-	env_set("silent_linux", NULL);
-	env_set("bootargs", CONSOLE_STR);
-	ut_assertok(bootm_process_cmdline_env(BOOTM_CL_SILENT));
-	ut_asserteq_str(CONSOLE_STR, env_get("bootargs"));
-
 	env_set("bootargs", NULL);
+	env_set("silent_linux", NULL);
 	ut_assertok(bootm_process_cmdline_env(BOOTM_CL_SILENT));
 	ut_assertnull(env_get("bootargs"));
 
-	ut_assertok(env_set("silent_linux", "no"));
 	env_set("bootargs", CONSOLE_STR);
-	ut_assertok(bootm_process_cmdline_env(BOOTM_CL_SILENT));
+	env_set("silent_linux", "yes");
-	ut_asserteq_str(CONSOLE_STR, env_get("bootargs"));
-
-	ut_assertok(env_set("silent_linux", "yes"));
-	env_set("bootargs", CONSOLE_STR);
-	ut_assertok(bootm_process_cmdline_env(BOOTM_CL_SILENT));
-	ut_asserteq_str("console=", env_get("bootargs"));
-
-	/* Empty buffer should still add the string */
-	env_set("bootargs", NULL);
 	ut_assertok(bootm_process_cmdline_env(BOOTM_CL_SILENT));
 	ut_asserteq_str("console=", env_get("bootargs"));