[source] ar71xx: enable serial console on Mikrotik RB411/RB433

[LEDE Commits]

mkresin pushed a commit to source.git, branch master:
https://git.lede-project.org/d7fd1a0f8da37a978b138b2966c12d06bda55df5

commit d7fd1a0f8da37a978b138b2966c12d06bda55df5
Author: David Varga <duvi at duvinet.hu>
AuthorDate: Tue Jan 10 19:12:34 2017 +0100

    ar71xx: enable serial console on Mikrotik RB411/RB433
    
    This patch adds support for serial console on Mikrotik RB411 and RB433
    series devices.
    
    Signed-off-by: David Varga <duvi at duvinet.hu>
    [picked from FS#377]
    Signed-off-by: Mathias Kresin <dev at kresin.me>
---
 .../ar71xx/patches-4.4/701-MIPS-ath79-add-routerboard-detection.patch | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/target/linux/ar71xx/patches-4.4/701-MIPS-ath79-add-routerboard-detection.patch b/target/linux/ar71xx/patches-4.4/701-MIPS-ath79-add-routerboard-detection.patch
index 77bf38c..b5f4616 100644
--- a/target/linux/ar71xx/patches-4.4/701-MIPS-ath79-add-routerboard-detection.patch
+++ b/target/linux/ar71xx/patches-4.4/701-MIPS-ath79-add-routerboard-detection.patch
@@ -1,12 +1,14 @@
 --- a/arch/mips/ath79/prom.c
 +++ b/arch/mips/ath79/prom.c
-@@ -136,6 +136,16 @@ void __init prom_init(void)
+@@ -136,6 +136,18 @@ void __init prom_init(void)
  		initrd_end = initrd_start + fw_getenvl("initrd_size");
  	}
  #endif
 +
 +	if (strstr(arcs_cmdline, "board=750Gr3") ||
 +	    strstr(arcs_cmdline, "board=750i") ||
++	    strstr(arcs_cmdline, "board=411") ||
++	    strstr(arcs_cmdline, "board=433") ||
 +	    strstr(arcs_cmdline, "board=450") ||
 +	    strstr(arcs_cmdline, "board=493") ||
 +	    strstr(arcs_cmdline, "board=951G") ||