hack: kernel: add generic image_cmdline hack to MIPS targets

lede-commit: d59f5b3a987a48508257a0ddbaeadc7909f9f976
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

arch/mips/Kconfig

@@ -1152,6 +1152,10 @@ config SYNC_R4K
 config MIPS_MACHINE
 	def_bool n
 
+config IMAGE_CMDLINE_HACK
+	bool "OpenWrt specific image command line hack"
+	default n
+
 config NO_IOPORT_MAP
 	def_bool n
 

arch/mips/kernel/head.S

@@ -79,6 +79,12 @@ FEXPORT(__kernel_entry)
 	j	kernel_entry
 #endif
 
+#ifdef CONFIG_IMAGE_CMDLINE_HACK
+	.ascii	"CMDLINE:"
+EXPORT(__image_cmdline)
+	.fill	0x400
+#endif /* CONFIG_IMAGE_CMDLINE_HACK */
+
 	__REF
 
 NESTED(kernel_entry, 16, sp)			# kernel entry point