Merge patch series "fw_loader: Split from fs_loader into separate library file"

This series from Marek Vasut <marek.vasut+renesas@mailbox.org> splits
the fw_loader "script" code out from the fs_loader code as the former
does not require the latter.

Link: https://lore.kernel.org/r/20250922114926.51984-1-marek.vasut+renesas@mailbox.org

3 files changed, 73 insertions, 0 deletions

diff --git a/lib/Kconfig b/lib/Kconfig
index 7e48b179f6d..f5c1731f456 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -71,6 +71,14 @@ config DYNAMIC_CRC_TABLE
 	  Enable this option to calculate entries for CRC tables at runtime.
 	  This can be helpful when reducing the size of the build image
 
+config FW_LOADER
+	bool "Enable firmware loader using environment script"
+	depends on CMDLINE
+	depends on ENV_SUPPORT
+	help
+	  Enable this option to make firmware loading using user-provided
+	  U-Boot environment script functionality accessible to U-Boot code.
+
 config HAVE_ARCH_IOMAP
 	bool
 	help
diff --git a/lib/Makefile b/lib/Makefile
index 2643bfc867c..a2e60668864 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -22,6 +22,8 @@ obj-$(CONFIG_AES) += aes.o
 obj-$(CONFIG_AES) += aes/
 obj-$(CONFIG_$(PHASE_)BINMAN_FDT) += binman.o
 
+obj-$(CONFIG_FW_LOADER) += fw_loader.o
+
 ifndef API_BUILD
 ifneq ($(CONFIG_CHARSET),)
 obj-y += charset.o
diff --git a/lib/fw_loader.c b/lib/fw_loader.c
new file mode 100644
index 00000000000..f776e09523a
--- /dev/null
+++ b/lib/fw_loader.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2025 Lucien Jheng <lucienzx159@gmail.com>
+ */
+
+#include <command.h>
+#include <env.h>
+#include <errno.h>
+#include <linux/types.h>
+#include <log.h>
+
+int request_firmware_into_buf_via_script(void *buf, size_t max_size,
+					 const char *script_name,
+					 size_t *retsize)
+{
+	char env_addr[CONFIG_SYS_CBSIZE] = { 0 };
+	char env_size[CONFIG_SYS_CBSIZE] = { 0 };
+	char *args[2] = { "run", (char *)script_name };
+	int ret, repeatable;
+	ulong addr, size;
+
+	if (!buf || !script_name || !max_size)
+		return -EINVAL;
+
+	/* Run the firmware loading script */
+	ret = cmd_process(0, 2, args, &repeatable, NULL);
+	if (ret) {
+		log_err("Firmware loading script '%s' not defined or failed.\n",
+			script_name);
+		return -EINVAL;
+	}
+
+	/* Prefix the FW loader variables with the script prefix */
+	snprintf(env_addr, sizeof(env_addr), "%s_addr", script_name);
+	snprintf(env_size, sizeof(env_size), "%s_size", script_name);
+
+	/* Find out where the firmware got loaded and how long it is */
+	addr = env_get_hex(env_addr, 0);
+	size = env_get_hex(env_size, 0);
+
+	/* Clear the variables set by the firmware loading script */
+	env_set(env_addr, NULL);
+	env_set(env_size, NULL);
+
+	if (!addr || !size) {
+		log_err("Firmware address (0x%lx) or size (0x%lx) are invalid.\n",
+			addr, size);
+		return -EINVAL;
+	}
+
+	if (size > max_size) {
+		log_err("Loaded firmware size 0x%lx exceeded maximum allowed size 0x%zx.\n",
+			size, max_size);
+		return -E2BIG;
+	}
+
+	if (retsize)
+		*retsize = size;
+
+	memcpy(buf, (void *)addr, size);
+
+	return 0;
+}