--- a/arch/mips/ath79/machtypes.h
+++ b/arch/mips/ath79/machtypes.h
@@ -51,6 +51,7 @@ enum ath79_mach_type {
 	ATH79_MACH_RB_493,		/* Mikrotik RouterBOARD 493/493AH */
 	ATH79_MACH_RB_493G,		/* Mikrotik RouterBOARD 493G */
 	ATH79_MACH_RB_750,		/* MikroTik RouterBOARD 750 */
+	ATH79_MACH_RB_750G_R3,		/* MikroTik RouterBOARD 750GL */
 	ATH79_MACH_RW2458N,		/* Redwave RW2458N */
 	ATH79_MACH_TEW_632BRP,		/* TRENDnet TEW-632BRP */
 	ATH79_MACH_TEW_673GRU,		/* TRENDnet TEW-673GRU */
--- a/arch/mips/ath79/prom.c
+++ b/arch/mips/ath79/prom.c
@@ -180,6 +180,9 @@ void __init prom_init(void)
 			ath79_prom_append_cmdline("board", env);
 		}
 	}
+
+	if (strstr(arcs_cmdline, "board=750Gr3"))
+		ath79_prom_append_cmdline("console", "ttyS0,115200");
 }
 
 void __init prom_free_prom_memory(void)
