[openwrt/openwrt] uboot-envtools: add fw_loadenv tool

[LEDE Commits]

blogic pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/84577e48bcfac9e9f12835ecf13a5e0ba2f71be2

commit 84577e48bcfac9e9f12835ecf13a5e0ba2f71be2
Author: John Crispin <john at phrozen.org>
AuthorDate: Tue Sep 17 14:36:13 2024 +0200

    uboot-envtools: add fw_loadenv tool
    
    This tool will load the uboot environment to /var/run/uboot-env/. This allows
    more efficient use when accessing multiple variables.
    
    Signed-off-by: John Crispin <john at phrozen.org>
---
 package/boot/uboot-envtools/Makefile         |  1 +
 package/boot/uboot-envtools/files/fw_loadenv | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/package/boot/uboot-envtools/Makefile b/package/boot/uboot-envtools/Makefile
index 19c3073c74..875afad554 100644
--- a/package/boot/uboot-envtools/Makefile
+++ b/package/boot/uboot-envtools/Makefile
@@ -71,6 +71,7 @@ define Package/uboot-envtools/install
 	$(LN) fw_printenv $(1)/usr/sbin/fw_setenv
 	$(INSTALL_BIN) ./files/fw_printsys $(1)/usr/sbin
 	$(INSTALL_BIN) ./files/fw_setsys $(1)/usr/sbin
+	$(INSTALL_BIN) ./files/fw_loadenv $(1)/usr/sbin
 	$(INSTALL_DIR) $(1)/lib
 	$(INSTALL_DATA) ./files/uboot-envtools.sh $(1)/lib
 	$(INSTALL_DIR) $(1)/etc/uci-defaults
diff --git a/package/boot/uboot-envtools/files/fw_loadenv b/package/boot/uboot-envtools/files/fw_loadenv
new file mode 100644
index 0000000000..9fe302ce89
--- /dev/null
+++ b/package/boot/uboot-envtools/files/fw_loadenv
@@ -0,0 +1,26 @@
+#!/usr/bin/ucode
+
+'use strict';
+
+const path = '/var/run/uboot-env/';
+
+import * as fs from 'fs';
+
+if (fs.lsdir(path)) {
+	warn(`env has already been loaded to ${path}\n`);
+	exit(0);
+}
+
+let fp = fs.popen('fw_printenv');
+let raw = fp.read('all');
+fp.close();
+
+if (!length(raw))
+	exit(0);
+
+fs.mkdir(path);
+for (let line in split(raw, '\n')) {
+	let vals = split(line, '=');
+	if (vals[0] && vals[1])
+		fs.writefile(path + vals[0], vals[1]);
+}