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path: root/target/linux/mpc85xx/patches-4.14/102-powerpc-add-cmdline-override.patch
blob: 6a16a34a187c853666c3fd00c5e052aa35bc2d25 (plain)
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--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -835,6 +835,14 @@ config CMDLINE_FORCE
 	  This is useful if you cannot or don't want to change the
 	  command-line options your boot loader passes to the kernel.
 
+config CMDLINE_OVERRIDE
+    bool "Use alternative cmdline from device tree"
+    help
+      Some bootloaders may have uneditable bootargs. While CMDLINE_FORCE can
+      be used, this is not a good option for kernels that are shared across
+      devices. This setting enables using "chosen/cmdline-override" as the
+      cmdline if it exists in the device tree.
+
 config EXTRA_TARGETS
 	string "Additional default image types"
 	help
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -1131,6 +1131,17 @@ int __init early_init_dt_scan_chosen(uns
 	if (p != NULL && l > 0)
 		strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
 
+    /* CONFIG_CMDLINE_OVERRIDE is used to fallback to a different
+     * device tree option of chosen/bootargs-override. This is
+     * helpful on boards where u-boot sets bootargs, and is unable
+     * to be modified.
+     */
+#ifdef CONFIG_CMDLINE_OVERRIDE
+	p = of_get_flat_dt_prop(node, "bootargs-override", &l);
+	if (p != NULL && l > 0)
+		strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
+#endif
+
 	/*
 	 * CONFIG_CMDLINE is meant to be a default in case nothing else
 	 * managed to set the command line, unless CONFIG_CMDLINE_FORCE