The prebuild linux-5.6.0-rc1 image for Maix Boards https://twitter.com/SipeedIO/status/1228594799675990016
[ 0.000000] Linux version 5.6.0-rc1-g9dbcd412b (vowstar@ryzen) (gcc version 9.2.0 (Buildroot 2020.02-git-g2ceb6f4a3f)) #5 SMP Sat Feb 15 13:02:55 CST 2020
[ 0.000000] earlycon: sifive0 at MMIO 0x0000000038000000 (options '')
[ 0.000000] printk: bootconsole [sifive0] enabled
[ 0.000000] initrd not found or empty - disabling initrd
[ 0.000000] Zone ranges:
[ 0.000000] DMA32 [mem 0x0000000080000000-0x00000000807fffff]
[ 0.000000] Normal empty
[ 0.000000] Movable zone start for each node
[ 0.000000] Early memory node ranges
[ 0.000000] node 0: [mem 0x0000000080000000-0x00000000807fffff]
[ 0.000000] Initmem setup node 0 [mem 0x0000000080000000-0x00000000807fffff]
[ 0.000000] elf_hwcap is 0x112d
[ 0.000000] percpu: max_distance=0x18000 too large for vmalloc space 0x0
[ 0.000000] percpu: Embedded 12 pages/cpu s18272 r0 d30880 u49152
[ 0.000000] Built 1 zonelists, mobility grouping off. Total pages: 2020
[ 0.000000] Kernel command line: earlycon console=ttySIF0
[ 0.000000] Dentry cache hash table entries: 1024 (order: 1, 8192 bytes, linear)
[ 0.000000] Inode-cache hash table entries: 512 (order: 0, 4096 bytes, linear)
[ 0.000000] Sorting __ex_table...
[ 0.000000] mem auto-init: stack:off, heap alloc:off, heap free:off
[ 0.000000] Memory: 6272K/8192K available (918K kernel code, 106K rwdata, 166K rodata, 385K init, 91K bss, 1920K reserved, 0K cma-reserved)
[ 0.000000] rcu: Hierarchical RCU implementation.
[ 0.000000] rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.
[ 0.000000] NR_IRQS: 0, nr_irqs: 0, preallocated irqs: 0
[ 0.000000] plic: mapped 65 interrupts with 2 handlers for 4 contexts.
[ 0.000000] riscv_timer_init_dt: Registering clocksource cpuid [0] hartid [0]
[ 0.000000] clocksource: riscv_clocksource: mask: 0xffffffffffffffff max_cycles: 0x3990be68b, max_idle_ns: 881590404272 ns
[ 0.000014] sched_clock: 64 bits at 7MHz, resolution 128ns, wraps every 4398046511054ns
[ 0.008236] Console: colour dummy device 80x25
[ 0.012473] Calibrating delay loop (skipped), value calculated using timer frequency.. 15.60 BogoMIPS (lpj=31200)
[ 0.022677] pid_max: default: 4096 minimum: 301
[ 0.027294] Mount-cache hash table entries: 512 (order: 0, 4096 bytes, linear)
[ 0.034414] Mountpoint-cache hash table entries: 512 (order: 0, 4096 bytes, linear)
[ 0.044809] rcu: Hierarchical SRCU implementation.
[ 0.049611] smp: Bringing up secondary CPUs ...
[ 0.054750] smp: Brought up 1 node, 2 CPUs
[ 0.059132] devtmpfs: initialized
[ 0.065719] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645041785100000 ns
[ 0.074738] futex hash table entries: 16 (order: -2, 1024 bytes, linear)
[ 0.082747] Kendryte K210 SoC sysctl
[ 0.096426] clocksource: Switched to clocksource riscv_clocksource
[ 0.189554] workingset: timestamp_bits=62 max_order=11 bucket_order=0
[ 0.196900] 38000000.serial: ttySIF0 at MMIO 0x38000000 (irq = 1, base_baud = 0) is a SiFive UART v0
[ 0.205372] printk: console [ttySIF0] enabled
[ 0.205372] printk: console [ttySIF0] enabled
[ 0.213983] printk: bootconsole [sifive0] disabled
[ 0.213983] printk: bootconsole [sifive0] disabled
[ 0.226523] random: get_random_bytes called from 0x0000000080065128 with crng_init=0
[ 0.235115] devtmpfs: mounted
[ 0.238516] Freeing unused kernel memory: 384K
[ 0.242223] This architecture does not have kernel memory protection.
[ 0.248642] Run /sbin/init as init process
[ 0.252828] Run /etc/init as init process
[ 0.257006] Run /bin/init as init process
----------------[ 0.266890] unexpected interrupt cause 0x8000000000000009
[ 0.266901] ------------[ cut here ]------------
[ 0.276874] kernel BUG at arch/riscv/kernel/irq.c:43!
[ 0.281908] Kernel BUG [#1]
[ 0.284695] CPU: 1 PID: 1 Comm: sh Not tainted 5.6.0-rc1-g9dbcd412b #5
[ 0.291201] epc: 0000000080145f78 ra : 0000000080145f78 sp : 000000008078bec0
[ 0.298319] gp : 000000008018a9b0 tp : 0000000080786000 t0 : 0000000000046000
[ 0.305526] t1 : 5c5c5c5c5c207c2e t2 : 0000000000000008 s0 : 000000008078bee0
[ 0.312732] s1 : 000000008078bee0 a0 : 000000000000002d a1 : 0000000080190dbf
[ 0.319937] a2 : 0000000000000008 a3 : 0000000000000000 a4 : 0000000000000000
[ 0.327144] a5 : 0000000000000000 a6 : 0000000000000004 a7 : 00000000000000d7
[ 0.334351] s2 : 0000000000000000 s3 : 00000001001f9100 s4 : 8000000000000009
[ 0.341557] s5 : 0000000000000000 s6 : 0000000080447298 s7 : ffffffffffffffff
[ 0.348763] s8 : 000000000000000a s9 : 0000000000000000 s10: 0000000000000062
[ 0.355970] s11: 0000000000000010 t3 : ffffffffffffffff t4 : 0000000000000018
[ 0.363173] t5 : 0000000000000028 t6 : 00000000801909bd
[ 0.368472] status: 0000000000001800 badaddr: 0000000000000000 cause: 0000000000000003
[ 0.376580] ---[ end trace 1606611251fb8ffb ]---
[ 0.380989] Kernel panic - not syncing: Fatal exception in interrupt
[ 0.387311] SMP: stopping secondary CPUs
[ 0.391232] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---
note: my BiT has this USB chip: