bootstd: Use the bootargs env var for changing the cmdline

The "bootargs" environment variable is used to set the command-line
arguments to pass to the OS. Use this same mechanism with bootstd as well.
When the variable is updated, it is written to the current bootflow. When
the current bootflow is updated, the environment variable is updated too.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/boot/bootflow.c b/boot/bootflow.c
index 487552fa28c..b820678d41a 100644
--- a/boot/bootflow.c
+++ b/boot/bootflow.c
@@ -12,6 +12,7 @@
 #include <bootmeth.h>
 #include <bootstd.h>
 #include <dm.h>
+#include <env_internal.h>
 #include <malloc.h>
 #include <dm/device-internal.h>
 #include <dm/uclass-internal.h>
@@ -552,3 +553,60 @@ int bootflow_iter_check_system(const struct bootflow_iter *iter)
 
 	return -ENOTSUPP;
 }
+
+/**
+ * bootflow_cmdline_set() - Set the command line for a bootflow
+ *
+ * @value: New command-line string
+ * Returns 0 if OK, -ENOENT if no current bootflow, -ENOMEM if out of memory
+ */
+int bootflow_cmdline_set(struct bootflow *bflow, const char *value)
+{
+	char *cmdline = NULL;
+
+	if (value) {
+		cmdline = strdup(value);
+		if (!cmdline)
+			return -ENOMEM;
+	}
+
+	free(bflow->cmdline);
+	bflow->cmdline = cmdline;
+
+	return 0;
+}
+
+#ifdef CONFIG_BOOTSTD_FULL
+/**
+ * on_bootargs() - Update the cmdline of a bootflow
+ */
+static int on_bootargs(const char *name, const char *value, enum env_op op,
+		       int flags)
+{
+	struct bootstd_priv *std;
+	struct bootflow *bflow;
+	int ret;
+
+	ret = bootstd_get_priv(&std);
+	if (ret)
+		return 0;
+	bflow = std->cur_bootflow;
+	if (!bflow)
+		return 0;
+
+	switch (op) {
+	case env_op_create:
+	case env_op_overwrite:
+		ret = bootflow_cmdline_set(bflow, value);
+		if (ret && ret != ENOENT)
+			return 1;
+		return 0;
+	case env_op_delete:
+		bootflow_cmdline_set(bflow, NULL);
+		fallthrough;
+	default:
+		return 0;
+	}
+}
+U_BOOT_ENV_CALLBACK(bootargs, on_bootargs);
+#endif