Support for RBSXTsq2nD SXTsq Lite2

Has anyone an idea which pins are the serial port? It should be the same hardware as LHG 2. LHG 5 is already supported.

ok, I found the serial port (J8) like described here:

OpenWrt kernel loader for AR7XXX/AR9XXX
Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
Decompressing kernel... done!
Starting kernel at 80060000...

[    0.000000] Linux version 4.14.88 (buildbot@6167ddb9a6c5) (gcc version 7.3.0 (OpenWrt GCC 7.3.0 r8714-a969e96)) #0 Fri Dec 14 15:18:32 2018
[    0.000000] bootconsole [early0] enabled
[    0.000000] CPU0 revision is: 00019374 (MIPS 24Kc)
[    0.000000] SoC: Qualcomm Atheros QCA9533 ver 2 rev 0
[    0.000000] Determined physical RAM map:
[    0.000000]  memory: 04000000 @ 00000000 (usable)
[    0.000000] User-defined physical RAM map:
[    0.000000]  memory: 04000000 @ 00000000 (usable)
[    0.000000] Initrd not found or empty - disabling initrd
[    0.000000] Primary instruction cache 64kB, VIPT, 4-way, linesize 32 bytes.
[    0.000000] Primary data cache 32kB, 4-way, VIPT, cache aliases, linesize 32 bytes
[    0.000000] Zone ranges:
[    0.000000]   Normal   [mem 0x0000000000000000-0x0000000003ffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000000000000-0x0000000003ffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x0000000003ffffff]
[    0.000000] random: get_random_bytes called from start_kernel+0x8c/0x47c with crng_init=0
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 16256
[    0.000000] Kernel command line: no-uart no-buzzer no-nand parts=1 boot_part_size=16777216 gpio=0 HZ=325000000 mem=64M kmac=B8:69:F4:5A:E8:F2 board=lhg-hb board=lhg-hb ver=3.41 hw_opt=00284001 boot=1 mlc=11 console=ttyS0,115200 rootfstype=squashfs noinitrd
[    0.000000] MIPS: no machine found for id 'lhg-hb', supported machines:
[    0.000000] id                       name
[    0.000000] Generic                  Generic AR71XX/AR724X/AR913X based board
[    0.000000] 2011G                    (null)
[    0.000000] 2011r5                   (null)
[    0.000000] 2011US                   (null)
[    0.000000] 2011L                    (null)
[    0.000000] 493G                     MikroTik RouterBOARD 493G
[    0.000000] 493                      MikroTik RouterBOARD 493/AH
[    0.000000] 450G                     MikroTik RouterBOARD 450G
[    0.000000] 450                      MikroTik RouterBOARD 450
[    0.000000] 435G                     MikroTik RouterBOARD 435G
[    0.000000] 433U                     MikroTik RouterBOARD 433UAH
[    0.000000] 433                      MikroTik RouterBOARD 433/AH
[    0.000000] 411U                     MikroTik RouterBOARD 411U
[    0.000000] 411                      MikroTik RouterBOARD 411/A/AH
[    0.000000] 751g                     MikroTik RouterBOARD 751G
[    0.000000] 751                      MikroTik RouterBOARD 751
[    0.000000] 750Gr3                   MikroTik RouterBOARD 750GL
[    0.000000] 750i                     MikroTik RouterBOARD 750
[    0.000000] 711Gr100                 (null)
[    0.000000] 922gs                    (null)
[    0.000000] 951HnD                   MikroTik RouterBOARD 951Ui-2HnD
[    0.000000] 951G                     MikroTik RouterBOARD 951G-2HnD
[    0.000000] 931                      (null)
[    0.000000] wapg-sc                  (null)
[    0.000000] map2-hb                  (null)
[    0.000000] cap-hb                   (null)
[    0.000000] wap-lte                  (null)
[    0.000000] wap-hb                   (null)
[    0.000000] lhg                      (null)
[    0.000000] 750-hb                   (null)
[    0.000000] 962                      (null)
[    0.000000] 952-hb                   (null)
[    0.000000] 911L                     (null)
[    0.000000] H951L                    (null)
[    0.000000] map-hb                   (null)
[    0.000000] sxt5n                    MikroTik RouterBOARD SXT Lite5
[    0.000000] sxt2n                    MikroTik RouterBOARD SXT Lite2
[    0.000000] MIPS: no machine found for id 'lhg-hb', supported machines:
[    0.000000] id                       name
[    0.000000] Generic                  Generic AR71XX/AR724X/AR913X based board
[    0.000000] 2011G                    (null)
[    0.000000] 2011r5                   (null)
[    0.000000] 2011US                   (null)
[    0.000000] 2011L                    (null)
[    0.000000] 493G                     MikroTik RouterBOARD 493G
[    0.000000] 493                      MikroTik RouterBOARD 493/AH
[    0.000000] 450G                     MikroTik RouterBOARD 450G
[    0.000000] 450                      MikroTik RouterBOARD 450
[    0.000000] 435G                     MikroTik RouterBOARD 435G
[    0.000000] 433U                     MikroTik RouterBOARD 433UAH
[    0.000000] 433                      MikroTik RouterBOARD 433/AH
[    0.000000] 411U                     MikroTik RouterBOARD 411U
[    0.000000] 411                      MikroTik RouterBOARD 411/A/AH
[    0.000000] 751g                     MikroTik RouterBOARD 751G
[    0.000000] 751                      MikroTik RouterBOARD 751
[    0.000000] 750Gr3                   MikroTik RouterBOARD 750GL
[    0.000000] 750i                     MikroTik RouterBOARD 750
[    0.000000] 711Gr100                 (null)
[    0.000000] 922gs                    (null)
[    0.000000] 951HnD                   MikroTik RouterBOARD 951Ui-2HnD
[    0.000000] 951G                     MikroTik RouterBOARD 951G-2HnD
[    0.000000] 931                      (null)
[    0.000000] wapg-sc                  (null)
[    0.000000] map2-hb                  (null)
[    0.000000] cap-hb                   (null)
[    0.000000] wap-lte                  (null)
[    0.000000] wap-hb                   (null)
[    0.000000] lhg                      (null)
[    0.000000] 750-hb                   (null)
[    0.000000] 962                      (null)
[    0.000000] 952-hb                   (null)
[    0.000000] 911L                     (null)
[    0.000000] H951L                    (null)
[    0.000000] map-hb                   (null)
[    0.000000] sxt5n                    MikroTik RouterBOARD SXT Lite5
[    0.000000] sxt2n                    MikroTik RouterBOARD SXT Lite2
[    0.000000] PID hash table entries: 256 (order: -2, 1024 bytes)
[    0.000000] Dentry cache hash table entries: 8192 (order: 3, 32768 bytes)
[    0.000000] Inode-cache hash table entries: 4096 (order: 2, 16384 bytes)
[    0.000000] Writing ErrCtl register=00000000
[    0.000000] Readback ErrCtl register=00000000
[    0.000000] Memory: 56952K/65536K available (4121K kernel code, 170K rwdata, 932K rodata, 2128K init, 212K bss, 8584K reserved, 0K cma-reserved)
[    0.000000] SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[    0.000000] NR_IRQS: 51
[    0.000000] Clocks: CPU:650.000MHz, DDR:600.000MHz, AHB:300.000MHz, Ref:25.000MHz
[    0.000000] clocksource: MIPS: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 5880801374 ns
[    0.000009] sched_clock: 32 bits at 325MHz, resolution 3ns, wraps every 6607641598ns
[    0.008864] Calibrating delay loop... 432.53 BogoMIPS (lpj=2162688)
[    0.075985] pid_max: default: 32768 minimum: 301
[    0.081436] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[    0.088944] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[    0.099333] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[    0.110539] futex hash table entries: 256 (order: -1, 3072 bytes)
[    0.118624] NET: Registered protocol family 16
[    0.125280] MIPS: machine is Generic AR71XX/AR724X/AR913X based board
[    0.151760] clocksource: Switched to clocksource MIPS
[    0.158536] NET: Registered protocol family 2
[    0.164367] TCP established hash table entries: 1024 (order: 0, 4096 bytes)
[    0.172337] TCP bind hash table entries: 1024 (order: 0, 4096 bytes)
[    0.179555] TCP: Hash tables configured (established 1024 bind 1024)
[    0.186928] UDP hash table entries: 256 (order: 0, 4096 bytes)
[    0.193611] UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
[    0.200961] NET: Registered protocol family 1
[    2.422400] Crashlog allocated RAM at address 0x3f00000
[    2.429633] workingset: timestamp_bits=30 max_order=14 bucket_order=0
[    2.441981] squashfs: version 4.0 (2009/01/31) Phillip Lougher
[    2.448594] jffs2: version 2.2 (NAND) (SUMMARY) (LZMA) (RTIME) (CMODE_PRIORITY) (c) 2001-2006 Red Hat, Inc.
[    2.571805] random: fast init done
[    2.595118] io scheduler noop registered
[    2.599571] io scheduler deadline registered (default)
[    2.605845] Serial: 8250/16550 driver, 16 ports, IRQ sharing enabled
[    2.615135] console [ttyS0] disabled
[    2.639327] serial8250.0: ttyS0 at MMIO 0x18020000 (irq = 11, base_baud = 1562500) is a 16550A
[    2.649127] console [ttyS0] enabled
[    2.649127] console [ttyS0] enabled
[    2.656680] bootconsole [early0] disabled
[    2.656680] bootconsole [early0] disabled
[    2.667060] libphy: Fixed MDIO Bus: probed
[    2.673493] NET: Registered protocol family 10
[    2.689801] Segment Routing with IPv6
[    2.693753] NET: Registered protocol family 17
[    2.698389] bridge: filtering via arp/ip/ip6tables is no longer available by default. Update your scripts to load br_netfilter if you need this.
[    2.711788] 8021q: 802.1Q VLAN Support v1.8
[    2.716268] rb: no calibration data found
[    2.735640] Freeing unused kernel memory: 2128K
[    2.740325] This architecture does not have kernel memory protection.
[    2.760557] init: Console is alive
[    2.764481] init: - watchdog -
[    2.788604] kmodloader: loading kernel modules from /etc/modules-boot.d/*
[    2.797885] kmodloader: done loading kernel modules from /etc/modules-boot.d/*
[    2.815869] init: - preinit -
Press the [f] key and hit [enter] to enter failsafe mode
Press the [1], [2], [3] or [4] key and hit [enter] to select the debug level
[    6.106359] procd: - early -
[    6.109438] procd: - watchdog -
[    6.656059] procd: - watchdog -
[    6.659577] procd: - ubus -
[    6.669764] random: ubusd: uninitialized urandom read (4 bytes read)
[    6.712527] random: ubusd: uninitialized urandom read (4 bytes read)
[    6.719533] random: ubusd: uninitialized urandom read (4 bytes read)
[    6.727060] procd: - init -
Please press Enter to activate this console.
[    6.897426] kmodloader: loading kernel modules from /etc/modules.d/*
[    6.908037] ip6_tables: (C) 2000-2006 Netfilter Core Team
[    6.924116] Loading modules backported from Linux version v4.19.7-0-g61c68f2a2af0
[    6.931907] Backport generated by backports.git v4.19.7-1-0-g148b072d
[    6.941476] ip_tables: (C) 2000-2006 Netfilter Core Team
[    6.955442] nf_conntrack version 0.5.0 (1024 buckets, 4096 max)
[    7.019146] xt_time: kernel timezone is -0000
[    7.080177] PPP generic driver version 2.4.2
[    7.087102] NET: Registered protocol family 24
[    7.129318] kmodloader: done loading kernel modules from /etc/modules.d/*
[    8.248629] urandom_read: 5 callbacks suppressed
[    8.248638] random: jshn: uninitialized urandom read (4 bytes read)
[    8.319702] random: jshn: uninitialized urandom read (4 bytes read)

I will compile with target/linux/ar71xx/patches-4.14/701-MIPS-ath79-add-routerboard-detection.patch

  •       strstr(arcs_cmdline, "board=lhg-hb") ||
    

and see if RX works.