I actually had to reverse tx and rx to make it work even though its clearly marked on my serial-adapter as well as on the motherboard.
This is a short boot start log:
F0: 102B 0000
FA: 1042 0000
FA: 1042 0000 [0200]
F9: 0000 0000
V0: 0000 0000 [0001]
00: 0000 0000
BP: 0600 0041 [0000]
G0: 1190 0000
EC: 0000 0000 [1000]
MK: 0000 0000 [0000]
T0: 0000 019F [0101]
Jump to BL
NOTICE: BL2: v2.10.0(release):
NOTICE: BL2: Built : 14:59:39, May 28 2024
NOTICE: WDT: Cold boot
NOTICE: WDT: disabled
NOTICE: CPU: MT7988
NOTICE: EMI: Using DDR4 settings
NOTICE: EMI: Detected DRAM size: 1024 MB
NOTICE: EMI: complex R/W mem test passed
NOTICE: SPI_NAND parses attributes from parameter page.
NOTICE: SPI_NAND Detected ID 0xef
NOTICE: Page size 2048, Block size 131072, size 134217728
NOTICE: BL2: Booting BL31
NOTICE: BL31: v2.10.0(release):
NOTICE: BL31: Built : 14:59:48, May 28 2024
U-Boot 2024.04 (May 30 2024 - 18:58:13 +0800)
BT8 bootloader version: 1.0.0.2
CPU: MediaTek MT7988
Model: mt7988-rfb
DRAM: 1 GiB
Core: 44 devices, 12 uclasses, devicetree: separate
Loading Environment from MTD...
SPINAND raw ID: EF AE 21
spi-nand: spi_nand spi_nand@0: Winbond W25N01KV SPI NAND was found.
spi-nand: spi_nand spi_nand@0: 128 MiB, block size: 128 KiB, page size: 2048, OOB size: 94, ECC strength 4/512, custom ECC status.
*** Warning - bad CRC, using default environment
In: serial@11000000
Out: serial@11000000
Err: serial@11000000
ASUS BT8 gpio/led init
Net:
Warning: ethernet@15100000 (eth0) using random MAC address - ee:4a:f3:f0:26:7f
eth0: ethernet@15100000
ubi0: attaching mtd4
ubi0: scanning is finished
ubi0: attached mtd4 (name "UBI_DEV", size 124 MiB)
ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 126976 bytes
ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 2048
ubi0: VID header offset: 2048 (aligned 2048), data offset: 4096
ubi0: good PEBs: 992, bad PEBs: 0, corrupted PEBs: 0
ubi0: user volume: 5, internal volumes: 1, max. volumes count: 128
ubi0: max/mean erase counter: 7/4, WL threshold: 4096, image sequence number: 1694403399
ubi0: available PEBs: 0, total reserved PEBs: 992, PEBs reserved for bad PEB handling: 20
UBI: vol_id reserved_pebs alignment data_pad vol_type usable_leb_size used_ebs used_bytes last_eb_bytes corrupted upd_marker name_len name
UBI: 0 1 1 0 dynamic 1f000 1 1f000 1f000 0 0 5 nvram
UBI: 1 b 1 0 dynamic 1f000 b 155000 1f000 0 0 7 Factory
UBI: 2 b 1 0 dynamic 1f000 b 155000 1f000 0 0 8 Factory2
UBI: 3 218 1 0 dynamic 1f000 218 40e8000 1f000 0 0 5 linux
UBI: 4 199 1 0 dynamic 1f000 199 3187000 1f000 0 0 5 jffs2
UBI: 7fffefff 2 1 0 dynamic 1f000 2 3e000 2 0 0 d layout volume
Read 1396736 bytes from volume Factory to 000000007f6a7ff0
EEPROM set 0: OK (version 109)
Read 1396736 bytes from volume Factory2 to 000000007f6a7ff0
EEPROM set 1: OK (version 109)
Read 1396736 bytes from volume Factory to 000000007fb2e680
Select EEPROM set 0 at offset 0x0.
BT8 bootloader version: 1.0.0.2
MAC Address: CC:28:AA:72:39:64
Please choose the operation:
1: Load System code to SDRAM via TFTP.
2: Load System code then write to Flash via TFTP.
3: Boot System code via Flash (default).
4: Entr boot command line interface.
7: Load Boot Loader code then write to Flash via Serial.
9: Load Boot Loader code then write to Flash via TFTP.
0
3: Boot System code via Flash (default).
HwID B
Read 40 bytes from volume linux to 0000000046000000
FIT/FDT format image found at 0x46000000,size 0x3db8f38
Read 64720736 bytes from volume linux to 0000000046000000
## Loading kernel from FIT Image at 46000000 ...
Using 'config-1' configuration
Trying 'kernel-1' kernel subimage
Description: ARM64 OpenWrt Linux-3.0
Type: Kernel Image
Compression: lzma compressed
Data Start: 0x460000e4
Data Size: 3419904 Bytes = 3.3 MiB
Architecture: AArch64
OS: Linux
Load Address: 0x48080000
Entry Point: 0x48080000
Hash algo: crc32
Hash value: 5e5c664d
Hash algo: sha1
Hash value: fc254683db45e642c04ebb0a46e3a5b0239f525a
Verifying Hash Integrity ... crc32+ sha1+ OK
## Loading ramdisk from FIT Image at 46000000 ...
Using 'config-1' configuration
Trying 'rootfs-1' ramdisk subimage
Description: Root File System
Type: RAMDisk Image
Compression: uncompressed
Data Start: 0x4634ad24
Data Size: 61267229 Bytes = 58.4 MiB
Architecture: Unknown Architecture
OS: Unknown OS
Load Address: 0x00000000
Entry Point: 0x00000000
Hash algo: crc32
Hash value: 37a3facc
Hash algo: sha1
Hash value: a3946e1fddb99db79994406597ddee31abfe36b6
Verifying Hash Integrity ... crc32+ sha1+ OK
## Loading fdt from FIT Image at 46000000 ...
Using 'config-1' configuration
Trying 'fdt-1' fdt subimage
Description: ARM64 OpenWrt mt7986d-bt8 device tree blob
Type: Flat Device Tree
Compression: uncompressed
Data Start: 0x46343120
Data Size: 31504 Bytes = 30.8 KiB
Architecture: AArch64
Hash algo: crc32
Hash value: 9f418426
Hash algo: sha1
Hash value: 8922d50fe2610b3be29f5a49dc5b905a7e54c023
Verifying Hash Integrity ... crc32+ sha1+ OK
Booting using the fdt blob at 0x46343120
Working FDT set to 46343120
Uncompressing Kernel Image to 48080000
Loading Device Tree to 000000007f7ee000, end 000000007f7f8b0f ... OK
Working FDT set to 7f7ee000
Starting kernel ...
Booting Linux on physical CPU 0x0000000000 [0x411fd090]
Linux version 5.4.271 (root@asus) (gcc version 8.4.0 (OpenWrt GCC 8.4.0 r0-febaa0c8)) #1 SMP Mon Oct 7 11:00:01 CST 2024
Machine model: ASUS BT8
earlycon: uart8250 at MMIO32 0x0000000011000000 (options '')
printk: bootconsole [uart8250] enabled
On node 0 totalpages: 259256
DMA32 zone: 4096 pages used for memmap
DMA32 zone: 0 pages reserved
DMA32 zone: 259256 pages, LIFO batch:63
psci: probing for conduit method from DT.
psci: PSCIv1.1 detected in firmware.
psci: Using standard PSCI v0.2 function IDs
psci: MIGRATE_INFO_TYPE not supported.
psci: SMC Calling Convention v1.0
percpu: Embedded 23 pages/cpu s56024 r8192 d29992 u94208
pcpu-alloc: s56024 r8192 d29992 u94208 alloc=23*4096
pcpu-alloc: [0] 0 [0] 1 [0] 2
Detected VIPT I-cache on CPU0
CPU features: detected: GIC system register CPU interface
CPU features: kernel page table isolation disabled by kernel configuration
CPU features: detected: Spectre-BHB
Built 1 zonelists, mobility grouping on. Total pages: 255160
Kernel command line: root_rfs=0x34ad24 rootfstype=squashfs ubi.mtd=UBI_DEV console=ttyS0,115200n1 loglevel=8 earlycon=uart8250,mmio32,0x11000000 pci=pcie_bus_perf root=/dev/mtdblock4
Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes, linear)
Inode-cache hash table entries: 65536 (order: 7, 524288 bytes, linear)
mem auto-init: stack:off, heap alloc:off, heap free:off
Memory: 1006532K/1037024K available (7038K kernel code, 474K rwdata, 1744K rodata, 448K init, 309K bss, 30492K reserved, 0K cma-reserved)
SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=3, Nodes=1
Invalid signature of oopsbuf: FF-FF-FF-FF-FF-FF-FF-FF (len -1)
rcu: Hierarchical RCU implementation.
rcu: CONFIG_RCU_FANOUT set to non-default value of 32.
rcu: RCU restricting CPUs from NR_CPUS=4 to nr_cpu_ids=3.
rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.
rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=3
NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0
GICv3: GIC: Using split EOI/Deactivate mode
GICv3: 416 SPIs implemented
GICv3: 0 Extended SPIs implemented
GICv3: Distributor has no Range Selector support
GICv3: 16 PPIs implemented
GICv3: no VLPI support, no direct LPI support
GICv3: CPU0: found redistributor 0 region 0:0x000000000c080000
arch_timer: cp15 timer(s) running at 13.00MHz (phys).
clocksource: arch_sys_counter: mask: 0xffffffffffffff max_cycles: 0x2ff89eacb, max_idle_ns: 440795202429 ns
sched_clock: 56 bits at 13MHz, resolution 76ns, wraps every 4398046511101ns
Calibrating delay loop (skipped), value calculated using timer frequency.. 26.00 BogoMIPS (lpj=52000)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 2048 (order: 2, 16384 bytes, linear)
Mountpoint-cache hash table entries: 2048 (order: 2, 16384 bytes, linear)
ASID allocator initialised with 65536 entries
rcu: Hierarchical SRCU implementation.
smp: Bringing up secondary CPUs ...
Detected VIPT I-cache on CPU1
GICv3: CPU1: found redistributor 1 region 0:0x000000000c0a0000
CPU1: Booted secondary processor 0x0000000001 [0x411fd090]
Detected VIPT I-cache on CPU2
GICv3: CPU2: found redistributor 2 region 0:0x000000000c0c0000
CPU2: Booted secondary processor 0x0000000002 [0x411fd090]
smp: Brought up 1 node, 3 CPUs
SMP: Total of 3 processors activated.
CPU features: detected: 32-bit EL0 Support
CPU features: detected: CRC32 instructions
CPU: All CPU(s) started at EL2
alternatives: patching kernel code
devtmpfs: initialized
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645041785100000 ns
futex hash table entries: 1024 (order: 4, 65536 bytes, linear)
pinctrl core: initialized pinctrl subsystem
NET: Registered protocol family 16
DMA: preallocated 256 KiB pool for atomic allocations
SCSI subsystem initialized
libata version 3.00 loaded.
rbus 18000000.wbsys: PCI host bridge to bus 0004:00
pci_bus 0004:00: root bus resource [mem 0x18000000-0x18ffffff]
pci_bus 0004:00: root bus resource [bus 00-ff]
pci_bus 0004:00: scanning bus
pci 0004:00:00.0: [14c3:7981] type 00 class 0x000280
pci 0004:00:00.0: reg 0x10: [mem 0x18000000-0x1800000f 64bit]
pci 0004:00:00.0: reg 0x18: [mem 0x00000000-0x0000000f]
pci 0004:00:00.0: reg 0x1c: [mem 0x00000000-0x0000000f]
pci 0004:00:00.0: reg 0x20: [mem 0x00000000-0x0000000f]
pci 0004:00:00.0: reg 0x24: [mem 0x00000000-0x0000000f]
pci_bus 0004:00: fixups for bus
pci_bus 0004:00: bus scan returning with max=00
clocksource: Switched to clocksource arch_sys_counter
thermal_sys: Registered thermal governor 'step_wise'
thermal_sys: Registered thermal governor 'user_space'
NET: Registered protocol family 2
IP idents hash table entries: 16384 (order: 5, 131072 bytes, linear)
tcp_listen_portaddr_hash hash table entries: 512 (order: 1, 8192 bytes, linear)
TCP established hash table entries: 8192 (order: 4, 65536 bytes, linear)
TCP bind hash table entries: 8192 (order: 5, 131072 bytes, linear)
TCP: Hash tables configured (established 8192 bind 8192)
UDP hash table entries: 512 (order: 2, 16384 bytes, linear)
UDP-Lite hash table entries: 512 (order: 2, 16384 bytes, linear)
NET: Registered protocol family 1
PCI: CLS 0 bytes, default 64
workingset: timestamp_bits=62 max_order=18 bucket_order=0
squashfs: version 4.0 (2009/01/31) Phillip Lougher
Debug interface error
phy phy-usb-phy@11e10000.3: type_sw - reg 0x218, index 0
mtk-pcie 11300000.pcie: host bridge /pcie@11300000 ranges:
mtk-pcie 11300000.pcie: Parsing ranges property...
mtk-pcie 11300000.pcie: IO 0x30000000..0x301fffff -> 0x30000000
mtk-pcie 11300000.pcie: MEM 0x30200000..0x37ffffff -> 0x30200000
mtk-pcie 11300000.pcie: failed to get max link width
mtk-pcie 11300000.pcie: PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [bus 00-ff]
pci_bus 0000:00: root bus resource [io 0x0000-0x1fffff] (bus address [0x30000000-0x301fffff])
pci_bus 0000:00: root bus resource [mem 0x30200000-0x37ffffff]
pci_bus 0000:00: scanning bus
pci 0000:00:00.0: [14c3:7988] type 01 class 0x060400
pci 0000:00:00.0: reg 0x10: [mem 0x00000000-0x00007fff 64bit]
pci 0000:00:00.0: PME# supported from D0 D3hot D3cold
pci 0000:00:00.0: PME# disabled
pci_bus 0000:00: fixups for bus
pci 0000:00:00.0: scanning [bus 00-00] behind bridge, pass 0
pci 0000:00:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring
pci 0000:00:00.0: scanning [bus 00-00] behind bridge, pass 1
pci_bus 0000:01: scanning bus
pci 0000:01:00.0: [14c3:7990] type 00 class 0x028000
pci 0000:01:00.0: reg 0x10: [mem 0x00000000-0x001fffff 64bit pref]
pci 0000:01:00.0: reg 0x18: [mem 0x00000000-0x00007fff 64bit]
pci 0000:01:00.0: PME# supported from D0 D3hot D3cold
pci 0000:01:00.0: PME# disabled
pci_bus 0000:01: fixups for bus
pci_bus 0000:01: bus scan returning with max=01
pci_bus 0000:01: busn_res: [bus 01-ff] end is updated to 01
pci_bus 0000:00: bus scan returning with max=01
pci 0000:00:00.0: BAR 9: assigned [mem 0x30200000-0x303fffff 64bit pref]
pci 0000:00:00.0: BAR 8: assigned [mem 0x30400000-0x304fffff]
pci 0000:00:00.0: BAR 0: assigned [mem 0x30500000-0x30507fff 64bit]
pci 0000:01:00.0: BAR 0: assigned [mem 0x30200000-0x303fffff 64bit pref]
pci 0000:01:00.0: BAR 2: assigned [mem 0x30400000-0x30407fff 64bit]
pci 0000:00:00.0: PCI bridge to [bus 01]
pci 0000:00:00.0: bridge window [mem 0x30400000-0x304fffff]
pci 0000:00:00.0: bridge window [mem 0x30200000-0x303fffff 64bit pref]
pci 0000:00:00.0: Max Payload Size set to 256/ 256 (was 128), Max Read Rq 256
pci 0000:01:00.0: Max Payload Size set to 256/ 256 (was 128), Max Read Rq 256
mtk-pcie 11290000.pcie: host bridge /pcie@11290000 ranges:
mtk-pcie 11290000.pcie: Parsing ranges property...
mtk-pcie 11290000.pcie: IO 0x28000000..0x281fffff -> 0x28000000
mtk-pcie 11290000.pcie: MEM 0x28200000..0x2fffffff -> 0x28200000
mtk-pcie 11290000.pcie: failed to get max link width
mtk-pcie 11290000.pcie: PCI host bridge to bus 0002:00
pci_bus 0002:00: root bus resource [bus 00-ff]
pci_bus 0002:00: root bus resource [io 0x200000-0x3fffff] (bus address [0x28000000-0x281fffff])
pci_bus 0002:00: root bus resource [mem 0x28200000-0x2fffffff]
pci_bus 0002:00: scanning bus
pci 0002:00:00.0: [14c3:7988] type 01 class 0x060400
pci 0002:00:00.0: reg 0x10: [mem 0x00000000-0x00007fff 64bit]
pci 0002:00:00.0: PME# supported from D0 D3hot D3cold
pci 0002:00:00.0: PME# disabled
pci_bus 0002:00: fixups for bus
pci 0002:00:00.0: scanning [bus 00-00] behind bridge, pass 0
pci 0002:00:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring
pci 0002:00:00.0: scanning [bus 00-00] behind bridge, pass 1
pci_bus 0002:01: scanning bus
pci 0002:01:00.0: [14c3:7991] type 00 class 0x028000
pci 0002:01:00.0: reg 0x10: [mem 0x00000000-0x001fffff 64bit pref]
pci 0002:01:00.0: reg 0x18: [mem 0x00000000-0x00007fff 64bit]
pci 0002:01:00.0: PME# supported from D0 D3hot D3cold
pci 0002:01:00.0: PME# disabled
pci 0002:01:00.0: 7.876 Gb/s available PCIe bandwidth, limited by 8 GT/s x1 link at 0002:00:00.0 (capable of 15.752 Gb/s with 8 GT/s x2 link)
pci_bus 0002:01: fixups for bus
pci_bus 0002:01: bus scan returning with max=01
pci_bus 0002:01: busn_res: [bus 01-ff] end is updated to 01
pci_bus 0002:00: bus scan returning with max=01
pci 0002:00:00.0: BAR 9: assigned [mem 0x28200000-0x283fffff 64bit pref]
pci 0002:00:00.0: BAR 8: assigned [mem 0x28400000-0x284fffff]
pci 0002:00:00.0: BAR 0: assigned [mem 0x28500000-0x28507fff 64bit]
pci 0002:01:00.0: BAR 0: assigned [mem 0x28200000-0x283fffff 64bit pref]
pci 0002:01:00.0: BAR 2: assigned [mem 0x28400000-0x28407fff 64bit]
pci 0002:00:00.0: PCI bridge to [bus 01]
pci 0002:00:00.0: bridge window [mem 0x28400000-0x284fffff]
pci 0002:00:00.0: bridge window [mem 0x28200000-0x283fffff 64bit pref]
pci 0002:00:00.0: Max Payload Size set to 256/ 256 (was 128), Max Read Rq 256
pci 0002:01:00.0: Max Payload Size set to 256/ 256 (was 128), Max Read Rq 256
mtk-power-controller 11d10000.topmisc: /topmisc@11d10000/eth2p5@2: A default off power domain has been ON
Serial: 8250/16550 driver, 3 ports, IRQ sharing disabled
printk: console [ttyS0] disabled
11000000.serial: ttyS0 at MMIO 0x11000000 (irq = 16, base_baud = 2500000) is a ST16650V2
printk: console [ttyS0] enabled
printk: console [ttyS0] enabled
printk: bootconsole [uart8250] disabled
printk: bootconsole [uart8250] disabled
mtk_rng trng@1020f000: registered RNG driver
random: crng init done
spi-nand spi0.0: calibration result: 0x2
spi-nand spi0.0: Winbond W25N01KVxxIR SPI NAND was found. (ID: efae2100)
spi-nand spi0.0: 128 MiB, block size: 128 KiB, page size: 2048, OOB size: 96, ECC strength 4/512, custom ECC status.
2 fixed-partitions partitions found on MTD device spi0.0
Creating 2 MTD partitions on "spi0.0":
0x000000000000-0x000000400000 : "Bootloader"
0x000000400000-0x000008000000 : "UBI_DEV"
Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011)
IMQ driver loaded successfully. (numdevs = 8, numqueues = 1, imq_dev_accurate_stats = 1)
Hooking IMQ after NAT on PREROUTING.
Hooking IMQ before NAT on POSTROUTING.
mt7988-pinctrl 1001f000.pinctrl: invalid function mdio in map table
[mtk_hw_init] reset_lock:0, force:0
[mtk_hw_init] execute fe cold reset
mtk_soc_eth 15100000.ethernet: MDC is running on 8333333 Hz
Maxlinear Ethernet GPY211C mdio-bus:05: Firmware Version: 0x886F (release)
mtk_soc_eth 15100000.ethernet eth0: mediatek frame engine at 0xffffffc010b00000, irq 13
mtk_soc_eth 15100000.ethernet eth1: mediatek frame engine at 0xffffffc010b00000, irq 13
mtk_soc_eth 15100000.ethernet eth2: mediatek frame engine at 0xffffffc010b00000, irq 13
(unnamed net_device) (dummy): netif_napi_add() called with weight 256
PPP generic driver version 2.4.2
PPP BSD Compression module registered
PPP Deflate Compression module registered
PPP MPPE Compression module registered
NET: Registered protocol family 24
PPTP driver version 0.8.5
i2c /dev entries driver
vcore: supplied by rt5190a-buck1
proc: supplied by rt5190a-buck1
rt5190a-buck4: supplied by rt5190a-buck1
rt5190a-ldo: supplied by regulator-dummy
mtk-soc-temp-lvts 1100a000.lvts: [lvts_cal] golden_temp = 60
mtk-soc-temp-lvts 1100a000.lvts: [lvts_cal] num:g_count:g_count_rc 0:19515:5367 1:19523:0 2:19543:0 3:19546:0 4:19467:5393 5:19498:0 6:19478:0 7:19518:0
mtk-soc-temp-lvts 1100a000.lvts: [COUNT_RC_NOW] 0:5381 1:5379 2:5382 3:5380 4:5402 5:5399 6:5401 7:5402
mtk-soc-temp-lvts 1100a000.lvts: set_polling_speed 0, LVTSMONCTL1_0= 0x10000c,LVTSMONCTL2_0= 0x10001
mtk-soc-temp-lvts 1100a000.lvts: set_hw_filter 0, LVTSMSRCTL0_0= 0xb6d
mtk-soc-temp-lvts 1100a000.lvts: lvts0: read all 4 sensors in 10080 us, one in 2404 us
mtk-soc-temp-lvts 1100a000.lvts: set_polling_speed 1, LVTSMONCTL1_0= 0x10000c,LVTSMONCTL2_0= 0x10001
mtk-soc-temp-lvts 1100a000.lvts: set_hw_filter 1, LVTSMSRCTL0_0= 0xb6d
mtk-soc-temp-lvts 1100a000.lvts: lvts1: read all 4 sensors in 10080 us, one in 2404 us
mtk-soc-temp-lvts 1100a000.lvts: set_tc_hw_reboot_threshold: LVTS0, the dominator sensing point= 0
mtk-soc-temp-lvts 1100a000.lvts: set_tc_hw_reboot_threshold: LVTS1, the dominator sensing point= 0
cpu cpu0: dummy supplies not allowed for exclusive requests
And yes, i can press "4" and enter command line interface.