synology with usb serial jumpers

Synology Serial Console

My old Synology DS918+ is powered off and collecting dust. I figured I should be able to install mainline linux on it and turn it into a shell server with a lot of disk. 

iFixIt documents how to take the plastic shell off in order to get access to the system board itself. Basically, unscrew the two screws at the corners in the back of the unit, and slide the main (disk cage) forward. You can then pull the metal disk cage and system board apart. It's really easy.

Modders Inc also has a good post of which components are used. What caught my eye is in this picture the 6-pin, unlabeled connector on the bottom right of the system board.

picture of a Synology system board
look to the left of the red circle in this picture for the 6-pin connector

The pin order thanks to sharpen mask on that image above is:

5 3 1
6 4 2
J2 6-pin order

Thanks to "darrend", he correctly mapped out part of the pins:

Pins
1 3.3V
2 GND
4 TX
6 RX
darrend
synology usb to serial pinouts on J2 (green, white, black)
synology usb to serial pinouts on J2 (green, white, black)

For the serial connection via picocom/minicom, you want: 115200 8N1. You are then greeted with the boot messages:

GNU GRUB  version 2.00

Press "CTRL-C" for boot menu or it boots automatically in 3s.
Press "CTRL-C" for boot menu or it boots automatically in 2s.
Press "CTRL-C" for boot menu or it boots automatically in 1s.
Press "CTRL-C" for boot menu or it boots automatically in 0s.

Booting `SYNOLOGY_2'
Checking file [/zImage]...Passed.
Checking file [/rd.gz]...Passed.
Serial:
Custom Serial: Empty or invalid checksum.
MAC1: 001132b4cdd7
MAC2: 001132b4cdd8
MAC3: Empty or invalid checksum.
MAC4: Empty or invalid checksum.
MAC5: Empty or invalid checksum.
MAC6: Empty or invalid checksum.
MAC7: Empty or invalid checksum.
MAC8: Empty or invalid checksum.
[    0.000000] Initializing cgroup subsys cpuset
[    0.000000] Initializing cgroup subsys cpu
[    0.000000] Initializing cgroup subsys cpuacct
[    0.000000] Linux version 4.4.180+ (root@build15) (gcc version 7.5.0 (GCC) ) #42218 SMP Mon Oct 18 19:17:56 CST 2021
[    0.000000] Command line: root=/dev/md0 earlyprintk=apl console=ttyS2,115200n8 ihd_num=4 netif_num=2 HddHotplug=1 SataPortMap=23 sata_remap=0>2:1>3:2>0:3>1 syno_hw_version=DS918+ vender_format_version=2 syno_hdd_detect=18,179,176,175 syno_hdd_enable=21,20,19,9 syno_usb_vbus_gpio=13@0000:00:15.0@1,11@0000:00:15.0@2 SpectreAll_on sn= macs=001132b4cdd7,001132b4cdd8
[    0.000000] KERNEL supported cpus:
[    0.000000]   Intel GenuineIntel
[    0.000000] x86/fpu: xstate_offset[3]:  960, xstate_sizes[3]:   64
[    0.000000] x86/fpu: xstate_offset[4]: 1024, xstate_sizes[4]:   64
[    0.000000] x86/fpu: Supporting XSAVE feature 0x01: 'x87 floating point registers'
[    0.000000] x86/fpu: Supporting XSAVE feature 0x02: 'SSE registers'
[    0.000000] x86/fpu: Supporting XSAVE feature 0x08: 'MPX bounds registers'
[    0.000000] x86/fpu: Supporting XSAVE feature 0x10: 'MPX CSR'
[    0.000000] x86/fpu: Enabled xstate features 0x1b, context size is 1088 bytes, using 'standard' format.
[    0.000000] e820: BIOS-provided physical RAM map:
[    0.000000] BIOS-e820: [mem 0x0000000000000000-0x0000000000057fff] usable
[    0.000000] BIOS-e820: [mem 0x0000000000058000-0x0000000000058fff] reserved
[    0.000000] BIOS-e820: [mem 0x0000000000059000-0x0000000000085fff] usable
[    0.000000] BIOS-e820: [mem 0x0000000000086000-0x00000000000fffff] reserved
[    0.000000] BIOS-e820: [mem 0x0000000000100000-0x000000000fffffff] usable
[    0.000000] BIOS-e820: [mem 0x0000000010000000-0x0000000012150fff] reserved
[    0.000000] BIOS-e820: [mem 0x0000000012151000-0x0000000067c17fff] usable
[    0.000000] BIOS-e820: [mem 0x0000000067c18000-0x0000000067c18fff] ACPI NVS
[    0.000000] BIOS-e820: [mem 0x0000000067c19000-0x0000000067c42fff] reserved
[    0.000000] BIOS-e820: [mem 0x0000000067c43000-0x0000000067c7dfff] usable
[    0.000000] BIOS-e820: [mem 0x0000000067c7e000-0x0000000068c7dfff] reserved
[    0.000000] BIOS-e820: [mem 0x0000000068c7e000-0x000000007822efff] usable
[    0.000000] BIOS-e820: [mem 0x000000007822f000-0x000000007aebefff] reserved
[    0.000000] BIOS-e820: [mem 0x000000007aebf000-0x000000007afbefff] ACPI NVS
[    0.000000] BIOS-e820: [mem 0x000000007afbf000-0x000000007affefff] ACPI data
[    0.000000] BIOS-e820: [mem 0x000000007afff000-0x000000007affffff] usable
[    0.000000] BIOS-e820: [mem 0x000000007b000000-0x000000007fffffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000d3709000-0x00000000d370afff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000e0000000-0x00000000e3ffffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fed01000-0x00000000fed01fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000ff800000-0x00000000ffffffff] reserved
[    0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000027fffffff] usable
[    0.000000] bootconsole [earlyser0] enabled
[    0.000000] NX (Execute Disable) protection: active
[    0.000000] extended physical RAM map:
[    0.000000] reserve setup_data: [mem 0x0000000000000000-0x0000000000057fff] usable
[    0.000000] reserve setup_data: [mem 0x0000000000058000-0x0000000000058fff] reserved
[    0.000000] reserve setup_data: [mem 0x0000000000059000-0x0000000000085fff] usable
[    0.000000] reserve setup_data: [mem 0x0000000000086000-0x00000000000fffff] reserved
[    0.000000] reserve setup_data: [mem 0x0000000000100000-0x0000000001dd9917] usable
[    0.000000] reserve setup_data: [mem 0x0000000001dd9918-0x0000000001dd9927] usable
[    0.000000] reserve setup_data: [mem 0x0000000001dd9928-0x000000000fffffff] usable
[    0.000000] reserve setup_data: [mem 0x0000000010000000-0x0000000012150fff] reserved
[    0.000000] reserve setup_data: [mem 0x0000000012151000-0x0000000067c17fff] usable
[    0.000000] reserve setup_data: [mem 0x0000000067c18000-0x0000000067c18fff] ACPI NVS
[    0.000000] reserve setup_data: [mem 0x0000000067c19000-0x0000000067c42fff] reserved
[    0.000000] reserve setup_data: [mem 0x0000000067c43000-0x0000000067c7dfff] usable
[    0.000000] reserve setup_data: [mem 0x0000000067c7e000-0x0000000068c7dfff] reserved
[    0.000000] reserve setup_data: [mem 0x0000000068c7e000-0x000000007822efff] usable
[    0.000000] reserve setup_data: [mem 0x000000007822f000-0x000000007aebefff] reserved
[    0.000000] reserve setup_data: [mem 0x000000007aebf000-0x000000007afbefff] ACPI NVS
[    0.000000] reserve setup_data: [mem 0x000000007afbf000-0x000000007affefff] ACPI data
[    0.000000] reserve setup_data: [mem 0x000000007afff000-0x000000007affffff] usable
[    0.000000] reserve setup_data: [mem 0x000000007b000000-0x000000007fffffff] reserved
[    0.000000] reserve setup_data: [mem 0x00000000d3709000-0x00000000d370afff] reserved
[    0.000000] reserve setup_data: [mem 0x00000000e0000000-0x00000000e3ffffff] reserved
[    0.000000] reserve setup_data: [mem 0x00000000fed01000-0x00000000fed01fff] reserved
[    0.000000] reserve setup_data: [mem 0x00000000ff800000-0x00000000ffffffff] reserved
[    0.000000] reserve setup_data: [mem 0x0000000100000000-0x000000027fffffff] usable
[    0.000000] efi: EFI v2.50 by INSYDE Corp.
[    0.000000] efi:  ACPI 2.0=0x7affe014  SMBIOS=0x78757000  SMBIOS 3.0=0x78755000 
[    0.000000] SMBIOS 3.0.0 present.
[    0.000000] e820: last_pfn = 0x280000 max_arch_pfn = 0x400000000
[    0.000000] x86/PAT: Configuration [0-7]: WB  WT  UC- UC  WB  WT  UC- UC  
[    0.000000] e820: last_pfn = 0x7b000 max_arch_pfn = 0x400000000
[    0.000000] Using GB pages for direct mapping
[    0.000000] RAMDISK: [mem 0x375e2000-0x37ae8fff]
[    0.000000] ACPI: Early table checksum verification disabled
[    0.000000] ACPI: RSDP 0x000000007AFFE014 000024 (v02 INSYDE)
[    0.000000] ACPI: XSDT 0x000000007AFDA188 0000DC (v01 INSYDE INSYDE   00000003      01000013)
[    0.000000] ACPI: FACP 0x000000007AFF5000 000114 (v06 INSYDE INSYDE   00000003 ACPI 00040000)
[    0.000000] ACPI: DSDT 0x000000007AFE6000 00772B (v02 INSYDE INSYDE   00000003 ACPI 00040000)
[    0.000000] ACPI: FACS 0x000000007AFAF000 000040
[    0.000000] ACPI: FACS 0x000000007AFAF000 000040
[    0.000000] ACPI: UEFI 0x000000007AFFD000 000236 (v01 INSYDE INSYDE   00000001 ACPI 00040000)
[    0.000000] ACPI: BDAT 0x000000007AFFB000 000030 (v02 INSYDE INSYDE   00000000 ACPI 00040000)
[    0.000000] ACPI: UEFI 0x000000007AFFA000 000042 (v01 INSYDE INSYDE   00000002 ACPI 00040000)
[    0.000000] ACPI: SSDT 0x000000007AFF9000 000554 (v01 INSYDE Tpm2Tabl 00001000 ACPI 00040000)
[    0.000000] ACPI: TPM2 0x000000007AFF8000 000034 (v03 INSYDE INSYDE   00000002 ACPI 00040000)
[    0.000000] ACPI: PSDS 0x000000007AFF7000 00004D (v01 INSYDE INSYDE   00000005 ACPI 00040000)
[    0.000000] ACPI: HPET 0x000000007AFF4000 000038 (v01 INSYDE INSYDE   00000003 ACPI 00040000)
[    0.000000] ACPI: LPIT 0x000000007AFF3000 00005C (v01 INSYDE INSYDE   00000003 ACPI 00040000)
[    0.000000] ACPI: APIC 0x000000007AFF2000 000084 (v03 INSYDE INSYDE   00000003 ACPI 00040000)
[    0.000000] ACPI: MCFG 0x000000007AFF1000 00003C (v01 INSYDE INSYDE   00000003 ACPI 00040000)
[    0.000000] ACPI: NPKT 0x000000007AFF0000 000065 (v01 INSYDE INSYDE   00000003 ACPI 00040000)
[    0.000000] ACPI: WDRT 0x000000007AFEF000 000047 (v01 INSYDE INSYDE   00000003 ACPI 00040000)
[    0.000000] ACPI: WSMT 0x000000007AFEE000 000028 (v01 INSYDE INSYDE   00000003 ACPI 00040000)
[    0.000000] ACPI: SSDT 0x000000007AFE4000 00024A (v02 INSYDE UsbCTabl 00000003 ACPI 00040000)
[    0.000000] ACPI: SSDT 0x000000007AFE3000 0000BC (v01 INSYDE Platform 00001000 ACPI 00040000)
[    0.000000] ACPI: SSDT 0x000000007AFE2000 00045A (v02 INSYDE Cpu0Ist  00003000 ACPI 00040000)
[    0.000000] ACPI: SSDT 0x000000007AFE1000 00072B (v02 INSYDE CpuSsdt  00003000 ACPI 00040000)
[    0.000000] ACPI: SSDT 0x000000007AFDE000 002760 (v02 INSYDE SaSsdt   00003000 ACPI 00040000)
[    0.000000] ACPI: FPDT 0x000000007AFDD000 000034 (v01 INSYDE INSYDE   00000002 ACPI 00040000)
[    0.000000] ACPI: WDAT 0x000000007AFF6000 000104 (v01 INSYDE INSYDE   00000000 ACPI 00040000)
[    0.000000] ACPI: BGRT 0x000000007AFE5000 000038 (v01 INSYDE INSYDE   00000001 ACPI 00040000)
[    0.000000] ACPI: NHLT 0x000000007AFDC000 00002D (v00 INTEL  EDK2     00000002      01000013)
[    0.000000] Zone ranges:
[    0.000000]   DMA      [mem 0x0000000000001000-0x0000000000ffffff]
[    0.000000]   DMA32    [mem 0x0000000001000000-0x00000000ffffffff]
[    0.000000]   Normal   [mem 0x0000000100000000-0x000000027fffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000000001000-0x0000000000057fff]
[    0.000000]   node   0: [mem 0x0000000000059000-0x0000000000085fff]
[    0.000000]   node   0: [mem 0x0000000000100000-0x000000000fffffff]
[    0.000000]   node   0: [mem 0x0000000012151000-0x0000000067c17fff]
[    0.000000]   node   0: [mem 0x0000000067c43000-0x0000000067c7dfff]
[    0.000000]   node   0: [mem 0x0000000068c7e000-0x000000007822efff]
[    0.000000]   node   0: [mem 0x000000007afff000-0x000000007affffff]
[    0.000000]   node   0: [mem 0x0000000100000000-0x000000027fffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000000001000-0x000000027fffffff]
[    0.000000] Reserving Intel graphics memory at [mem 0x7c000000-0x7fffffff]
[    0.000000] ACPI: PM-Timer IO Port: 0x408
[    0.000000] ACPI: LAPIC_NMI (acpi_id[0x01] high level lint[0x1])
[    0.000000] ACPI: LAPIC_NMI (acpi_id[0x02] high level lint[0x1])
[    0.000000] ACPI: LAPIC_NMI (acpi_id[0x03] high level lint[0x1])
[    0.000000] ACPI: LAPIC_NMI (acpi_id[0x04] high level lint[0x1])
[    0.000000] IOAPIC[0]: apic_id 1, version 32, address 0xfec00000, GSI 0-119
[    0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 dfl dfl)
[    0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 low level)
[    0.000000] Using ACPI (MADT) for SMP configuration information
[    0.000000] ACPI: HPET id: 0x8086a701 base: 0xfed00000
[    0.000000] smpboot: Allowing 4 CPUs, 0 hotplug CPUs
[    0.000000] PM: Registered nosave memory: [mem 0x00000000-0x00000fff]
[    0.000000] PM: Registered nosave memory: [mem 0x00058000-0x00058fff]
[    0.000000] PM: Registered nosave memory: [mem 0x00086000-0x000fffff]
[    0.000000] PM: Registered nosave memory: [mem 0x01dd9000-0x01dd9fff]
[    0.000000] PM: Registered nosave memory: [mem 0x01dd9000-0x01dd9fff]
[    0.000000] PM: Registered nosave memory: [mem 0x10000000-0x12150fff]
[    0.000000] PM: Registered nosave memory: [mem 0x67c18000-0x67c18fff]
[    0.000000] PM: Registered nosave memory: [mem 0x67c19000-0x67c42fff]
[    0.000000] PM: Registered nosave memory: [mem 0x67c7e000-0x68c7dfff]
[    0.000000] PM: Registered nosave memory: [mem 0x7822f000-0x7aebefff]
[    0.000000] PM: Registered nosave memory: [mem 0x7aebf000-0x7afbefff]
[    0.000000] PM: Registered nosave memory: [mem 0x7afbf000-0x7affefff]
[    0.000000] PM: Registered nosave memory: [mem 0x7b000000-0x7fffffff]
[    0.000000] PM: Registered nosave memory: [mem 0x80000000-0xd3708fff]
[    0.000000] PM: Registered nosave memory: [mem 0xd3709000-0xd370afff]
[    0.000000] PM: Registered nosave memory: [mem 0xd370b000-0xdfffffff]
[    0.000000] PM: Registered nosave memory: [mem 0xe0000000-0xe3ffffff]
[    0.000000] PM: Registered nosave memory: [mem 0xe4000000-0xfed00fff]
[    0.000000] PM: Registered nosave memory: [mem 0xfed01000-0xfed01fff]
[    0.000000] PM: Registered nosave memory: [mem 0xfed02000-0xff7fffff]
[    0.000000] PM: Registered nosave memory: [mem 0xff800000-0xffffffff]
[    0.000000] e820: [mem 0x80000000-0xd3708fff] available for PCI devices
[    0.000000] clocksource: refined-jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 1910969940391419 ns
[    0.000000] setup_percpu: NR_CPUS:8 nr_cpumask_bits:8 nr_cpu_ids:4 nr_node_ids:1
[    0.000000] PERCPU: Embedded 33 pages/cpu @ffff88027fc00000 s95128 r8192 d31848 u524288
[    0.000000] Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 2020062
[    0.000000] Kernel command line: root=/dev/md0 earlyprintk=apl console=ttyS2,115200n8 ihd_num=4 netif_num=2 HddHotplug=1 SataPortMap=23 sata_remap=0>2:1>3:2>0:3>1 syno_hw_version=DS918+ vender_format_version=2 syno_hdd_detect=18,179,176,175 syno_hdd_enable=21,20,19,9 syno_usb_vbus_gpio=13@0000:00:15.0@1,11@0000:00:15.0@2 SpectreAll_on sn= macs=001132b4cdd7,001132b4cdd8
[    0.000000] Internal HD num: 4
[    0.000000] Internal netif num: 2
[    0.000000] Support HDD Hotplug.
[    0.000000] Sata Port Map: 23
[    0.000000] SYNO: sata remap initialized
[    0.000000] Synology Hardware Version: DS918+
[    0.000000] Vender format version: 2
[    0.000000] SYNO GPIO hdd detect pin: 18 179 176 175 
[    0.000000] SYNO GPIO hdd enable pin: 21 20 19 9 
[    0.000000] USB Vbus GPIO Control:
[    0.000000]  Gpp#13 - Host: dev_name:usb2        - Port:1 - Polarity: ACTIVE_HIGH
[    0.000000]  Gpp#13 - Host: dev_name:usb1        - Port:3 - Polarity: ACTIVE_HIGH
[    0.000000]  Gpp#11 - Host: dev_name:usb2        - Port:2 - Polarity: ACTIVE_HIGH
[    0.000000]  Gpp#11 - Host: dev_name:usb1        - Port:1 - Polarity: ACTIVE_HIGH
[    0.000000] Serial Number: 
[    0.000000] PID hash table entries: 4096 (order: 3, 32768 bytes)
[    0.000000] Dentry cache hash table entries: 1048576 (order: 11, 8388608 bytes)
[    0.000000] Inode-cache hash table entries: 524288 (order: 10, 4194304 bytes)
[    0.000000] Memory: 7940280K/8208608K available (5624K kernel code, 863K rwdata, 1748K rodata, 916K init, 660K bss, 268328K reserved, 0K cma-reserved)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1
[    0.000000] Kernel/User page tables isolation: enabled
[    0.000000] Hierarchical RCU implementation.
[    0.000000] 	Build-time adjustment of leaf fanout to 64.
[    0.000000] 	RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=4.
[    0.000000] RCU: Adjusting geometry for rcu_fanout_leaf=64, nr_cpu_ids=4
[    0.000000] NR_IRQS:4352 nr_irqs:1024 16
[    0.000000] Console: colour dummy device 80x25
[    0.000000] clocksource: hpet: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 99544814920 ns
[    0.000000] tsc: PIT calibration matches HPET. 1 loops
[    0.000000] tsc: Detected 1497.571 MHz processor
[    0.000005] Calibrating delay loop (skipped), value calculated using timer frequency.. 2995.14 BogoMIPS (lpj=1497571)
[    0.011848] pid_max: default: 32768 minimum: 301
[    0.017005] ACPI: Core revision 20150930
[    0.035565] ACPI: 7 ACPI AML tables successfully acquired and loaded
[    0.047320] Security Framework initialized
[    0.051742] AppArmor: AppArmor initialized
[    0.056309] Mount-cache hash table entries: 16384 (order: 5, 131072 bytes)
[    0.063967] Mountpoint-cache hash table entries: 16384 (order: 5, 131072 bytes)
[    0.072511] Initializing cgroup subsys io
[    0.076827] Initializing cgroup subsys memory
[    0.081713] Initializing cgroup subsys devices
[    0.086628] Initializing cgroup subsys freezer
[    0.091626] CPU: Physical Processor ID: 0
[    0.096046] CPU: Processor Core ID: 0
[    0.112216] CPU0: Thermal monitoring enabled (TM1)
[    0.117447] Last level iTLB entries: 4KB 48, 2MB 0, 4MB 0
[    0.123418] Last level dTLB entries: 4KB 0, 2MB 0, 4MB 0, 1GB 0
[    0.130020] Spectre V1 : Mitigation: usercopy/swapgs barriers and __user pointer sanitization
[    0.139542] Spectre V2 : Mitigation: Full generic retpoline
[    0.145752] Spectre V2 : Spectre v2 / SpectreRSB mitigation: Filling RSB on context switch
[    0.154975] Spectre V2 : Enabling Restricted Speculation for firmware calls
[    0.162743] Spectre V2 : mitigation: Enabling conditional Indirect Branch Prediction Barrier
[    0.172162] Spectre V2 : User space: Mitigation: STIBP via prctl
[    0.182116] Freeing SMP alternatives memory: 24K
[    0.194678] ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
[    0.211215] smpboot: CPU0: Intel(R) Celeron(R) CPU J3455 @ 1.50GHz (family: 0x6, model: 0x5c, stepping: 0x9)
[    0.222029] Performance Events: PEBS fmt3+, generic architected perfmon, full-width counters, Intel PMU driver.
[    0.233265] ... version:                4
[    0.237731] ... bit width:              48
[    0.242295] ... generic registers:      4
[    0.246761] ... value mask:             0000ffffffffffff
[    0.252685] ... max period:             00007fffffffffff
[    0.258608] ... fixed-purpose events:   3
[    0.263076] ... event mask:             000000070000000f
[    0.269685] x86: Booting SMP configuration:
[    0.274161] .... node  #0, CPUs:      #1 #2 #3
[    0.321265] x86: Booted up 1 node, 4 CPUs
[    0.325743] smpboot: Total of 4 processors activated (11980.56 BogoMIPS)
[    0.335130] NMI watchdog: enabled on all CPUs, permanently consumes one hw-PMU counter.
[    0.344414] devtmpfs: initialized
[    0.348420] PM: Registering ACPI NVS region [mem 0x67c18000-0x67c18fff] (4096 bytes)
[    0.356883] PM: Registering ACPI NVS region [mem 0x7aebf000-0x7afbefff] (1048576 bytes)
[    0.365943] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 1911260446275000 ns
[    0.376699] futex hash table entries: 1024 (order: 4, 65536 bytes)
[    0.383761] pinctrl core: initialized pinctrl subsystem
[    0.389777] NET: Registered protocol family 16
[    0.404597] cpuidle: using governor ladder
[    0.416007] cpuidle: using governor menu
[    0.420344] ACPI FADT declares the system doesn't support PCIe ASPM, so disable it
[    0.428640] ACPI: bus type PCI registered
[    0.433229] PCI: MMCONFIG for domain 0000 [bus 00-3f] at [mem 0xe0000000-0xe3ffffff] (base 0xe0000000)
[    0.443498] PCI: MMCONFIG at [mem 0xe0000000-0xe3ffffff] reserved in E820
[    0.451078] PCI: Using configuration type 1 for base access
[    0.463991] ACPI: Added _OSI(Module Device)
[    0.468477] ACPI: Added _OSI(Processor Device)
[    0.473423] ACPI: Added _OSI(3.0 _SCP Extensions)
[    0.478666] ACPI: Added _OSI(Processor Aggregator Device)
[    0.491475] ACPI: Executed 3 blocks of module-level executable AML code
[    0.505058] ACPI: Dynamic OEM Table Load:
[    0.509346] ACPI: SSDT 0xFFFF8802762F3800 00015F (v02 PmRef  ApIst    00003000 INTL 20130117)
[    0.520819] ACPI: Interpreter enabled
[    0.524731] ACPI: (supports S0 S4 S5)
[    0.528785] ACPI: Using IOAPIC for interrupt routing
[    0.534382] PCI: Using host bridge windows from ACPI; if necessary, use "pci=nocrs" and report a bug
[    0.556569] ACPI: Power Resource [FN00] (on)
[    0.562339] ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff])
[    0.569062] acpi PNP0A08:00: _OSC: OS supports [ExtendedConfig ASPM ClockPM Segments MSI]
[    0.579169] acpi PNP0A08:00: _OSC: OS now controls [PME AER PCIeCapability]
[    0.586756] acpi PNP0A08:00: FADT indicates ASPM is unsupported, using BIOS configuration
[    0.595890] acpi PNP0A08:00: [Firmware Info]: MMCONFIG for domain 0000 [bus 00-3f] only partially covers this bridge
[    0.607960] PCI host bridge to bus 0000:00
[    0.612345] pci_bus 0000:00: root bus resource [io  0x0070-0x0077]
[    0.619239] pci_bus 0000:00: root bus resource [io  0x0000-0x006f window]
[    0.626814] pci_bus 0000:00: root bus resource [io  0x0078-0x0cf7 window]
[    0.634389] pci_bus 0000:00: root bus resource [io  0x0d00-0xffff window]
[    0.641966] pci_bus 0000:00: root bus resource [mem 0x7c000001-0x7fffffff window]
[    0.650319] pci_bus 0000:00: root bus resource [mem 0x7b800001-0x7bffffff window]
[    0.658668] pci_bus 0000:00: root bus resource [mem 0x80000000-0xcfffffff window]
[    0.667020] pci_bus 0000:00: root bus resource [mem 0xe0000000-0xefffffff window]
[    0.675371] pci_bus 0000:00: root bus resource [bus 00-ff]
[    0.683013] pci 0000:00:0e.0: System wakeup disabled by ACPI
[    0.691182] pci 0000:00:13.0: System wakeup disabled by ACPI
[    0.698217] pci 0000:00:13.2: System wakeup disabled by ACPI
[    0.705265] pci 0000:00:14.0: System wakeup disabled by ACPI
[    0.711912] pci 0000:00:15.0: System wakeup disabled by ACPI
[    0.723760] pci 0000:01:00.0: System wakeup disabled by ACPI
[    0.731921] pci 0000:00:13.0: PCI bridge to [bus 01]
[    0.737669] pci 0000:02:00.0: System wakeup disabled by ACPI
[    0.745824] pci 0000:00:13.1: PCI bridge to [bus 02]
[    0.751552] pci 0000:03:00.0: System wakeup disabled by ACPI
[    0.759707] pci 0000:00:13.2: PCI bridge to [bus 03]
[    0.765478] pci 0000:04:00.0: System wakeup disabled by ACPI
[    0.773632] pci 0000:00:13.3: PCI bridge to [bus 04]
[    0.779419] pci 0000:05:00.0: System wakeup disabled by ACPI
[    0.787573] pci 0000:00:14.0: PCI bridge to [bus 05]
[    0.793650] ACPI: PCI Interrupt Link [LNKA] (IRQs 3 4 5 6 10 11 12 14 *15), disabled.
[    0.802305] ACPI: PCI Interrupt Link [LNKB] (IRQs 3 4 5 6 10 11 12 14 *15), disabled.
[    0.811043] ACPI: PCI Interrupt Link [LNKC] (IRQs 3 4 5 6 10 11 12 14 *15), disabled.
[    0.819786] ACPI: PCI Interrupt Link [LNKD] (IRQs 3 4 5 6 10 11 12 14 *15), disabled.
[    0.828527] ACPI: PCI Interrupt Link [LNKE] (IRQs 3 4 5 6 10 11 12 14 *15), disabled.
[    0.837260] ACPI: PCI Interrupt Link [LNKF] (IRQs 3 4 5 6 10 11 12 14 *15), disabled.
[    0.846000] ACPI: PCI Interrupt Link [LNKG] (IRQs 3 4 5 6 10 11 12 14 *15), disabled.
[    0.854737] ACPI: PCI Interrupt Link [LNKH] (IRQs 3 4 5 6 10 11 12 14 *15), disabled.
[    0.865491] ACPI: Enabled 3 GPEs in block 00 to 7F
[    0.870878] vgaarb: setting as boot device: PCI:0000:00:02.0
[    0.877002] vgaarb: device added: PCI:0000:00:02.0,decodes=io+mem,owns=io+mem,locks=none
[    0.886052] vgaarb: loaded
[    0.889044] vgaarb: bridge control possible 0000:00:02.0
[    0.895092] SCSI subsystem initialized
[    0.899320] pps_core: LinuxPPS API ver. 1 registered
[    0.904691] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti <giometti@linux.it>
[    0.914885] PTP clock support registered
[    0.919400] EFI Variables Facility v0.08 2004-May-17
[    0.956005] pstore: Registered efi as persistent store backend
[    0.962357] PCI: Using ACPI for IRQ routing
[    0.974120] clocksource: Switched to clocksource hpet
[    0.992568] AppArmor: AppArmor Filesystem Enabled
[    0.997745] pnp: PnP ACPI init
[    1.001297] system 00:00: [io  0x0680-0x069f] has been reserved
[    1.007737] system 00:00: [io  0x0400-0x047f] has been reserved
[    1.014337] system 00:00: [io  0x0500-0x05fe] has been reserved
[    1.021549] system 00:01: [mem 0xe0000000-0xefffffff] could not be reserved
[    1.029206] system 00:01: [mem 0xfea00000-0xfeafffff] has been reserved
[    1.036535] system 00:01: [mem 0xfed01000-0xfed01fff] has been reserved
[    1.043912] system 00:01: [mem 0xfed03000-0xfed03fff] has been reserved
[    1.051292] system 00:01: [mem 0xfed06000-0xfed06fff] has been reserved
[    1.058671] system 00:01: [mem 0xfed08000-0xfed09fff] has been reserved
[    1.066054] system 00:01: [mem 0xfed80000-0xfedbffff] has been reserved
[    1.073433] system 00:01: [mem 0xfed1c000-0xfed1cfff] has been reserved
[    1.080813] system 00:01: [mem 0xfee00000-0xfeefffff] has been reserved
[    1.088848] pnp: PnP ACPI: found 3 devices
[    1.103306] clocksource: acpi_pm: mask: 0xffffff max_cycles: 0xffffff, max_idle_ns: 2085701024 ns
[    1.113056] pci 0000:01:00.0: can't claim BAR 6 [mem 0xffff0000-0xffffffff pref]: no compatible bridge window
[    1.124207] pci 0000:01:00.0: BAR 6: assigned [mem 0x91510000-0x9151ffff pref]
[    1.132222] pci 0000:00:13.0: PCI bridge to [bus 01]
[    1.137709] pci 0000:00:13.0:   bridge window [io  0x3000-0x3fff]
[    1.144511] pci 0000:00:13.0:   bridge window [mem 0x91500000-0x915fffff]
[    1.152086] pci 0000:00:13.1: PCI bridge to [bus 02]
[    1.157618] pci 0000:00:13.1:   bridge window [mem 0x91400000-0x914fffff]
[    1.165223] pci 0000:00:13.2: PCI bridge to [bus 03]
[    1.170727] pci 0000:00:13.2:   bridge window [mem 0x91300000-0x913fffff]
[    1.178306] pci 0000:00:13.3: PCI bridge to [bus 04]
[    1.183835] pci 0000:00:13.3:   bridge window [io  0x2000-0x2fff]
[    1.190635] pci 0000:00:13.3:   bridge window [mem 0x91200000-0x912fffff]
[    1.198226] pci 0000:00:14.0: PCI bridge to [bus 05]
[    1.203745] pci 0000:00:14.0:   bridge window [io  0x1000-0x1fff]
[    1.210543] pci 0000:00:14.0:   bridge window [mem 0x91100000-0x911fffff]
[    1.218272] NET: Registered protocol family 2
[    1.223263] TCP established hash table entries: 65536 (order: 7, 524288 bytes)
[    1.231519] TCP bind hash table entries: 65536 (order: 8, 1048576 bytes)
[    1.239395] TCP: Hash tables configured (established 65536 bind 65536)
[    1.246557] UDP hash table entries: 4096 (order: 5, 131072 bytes)
[    1.253402] UDP-Lite hash table entries: 4096 (order: 5, 131072 bytes)
[    1.260760] NET: Registered protocol family 1
[    1.267286] pci 0000:01:00.0: Apply mv9235 specific programming steps
[    1.579409] Trying to unpack rootfs image as initramfs...
[    3.550700] decompress cpio completed and skip redundant lzma
[    3.558702] Freeing initrd memory: 5148K
[    3.562924] PCI-DMA: Using software bounce buffering for IO (SWIOTLB)
[    3.570098] software IO TLB: mapped [mem 0x71ece000-0x75ece000] (64MB)
[    3.578897] audit: initializing netlink subsys (disabled)
[    3.584797] audit: type=2000 audit(1655281691.276:1): initialized
[    3.591911] Initialise system trusted keyring
[    3.661925] VFS: Disk quotas dquot_6.6.0
[    3.666281] VFS: Dquot-cache hash table entries: 512 (order 0, 4096 bytes)
[    3.895240] Key type asymmetric registered
[    3.899651] Asymmetric key parser 'x509' registered
[    3.905240] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 251)
[    3.913358] io scheduler noop registered
[    3.917710] io scheduler deadline registered
[    3.922588] io scheduler cfq registered (default)
[    3.929490] pcieport 0000:00:13.0: Signaling PME through PCIe PME interrupt
[    3.937095] pci 0000:01:00.0: Signaling PME through PCIe PME interrupt
[    3.944437] pcieport 0000:00:13.1: Signaling PME through PCIe PME interrupt
[    3.952143] pci 0000:02:00.0: Signaling PME through PCIe PME interrupt
[    3.959491] pcieport 0000:00:13.2: Signaling PME through PCIe PME interrupt
[    3.967234] pci 0000:03:00.0: Signaling PME through PCIe PME interrupt
[    3.974513] pcieport 0000:00:13.3: Signaling PME through PCIe PME interrupt
[    3.982271] pci 0000:04:00.0: Signaling PME through PCIe PME interrupt
[    3.989565] pcieport 0000:00:14.0: Signaling PME through PCIe PME interrupt
[    3.997300] pci 0000:05:00.0: Signaling PME through PCIe PME interrupt
[    4.578284] tsc: Refined TSC clocksource calibration: 1497.599 MHz
[    4.585044] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x1596467b3e4, max_idle_ns: 440795260276 ns
[    4.811398] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[    4.971376] Linux agpgart interface v0.103
[    5.010997] brd: module loaded
[    5.025177] idma64 idma64.0: Found Intel integrated DMA 64-bit
[    5.055315] idma64 idma64.1: Found Intel integrated DMA 64-bit
[    5.102352] dw-apb-uart.1: ttyS0 at MMIO 0x9161c000 (irq = 44, base_baud = 115200) is a 16550A
[    5.111867] console [ttyS2] enabled
[    5.115830] bootconsole [earlyser0] disabled
[    5.148876] console [ttyS2] enabled
[    5.158437] dw-apb-uart.4: ttyS3 at MMIO 0x91622000 (irq = 47, base_baud = 115200) is a 16550A
[    5.170367] idma64 idma64.5: Found Intel integrated DMA 64-bit
[    5.187781] idma64 idma64.6: Found Intel integrated DMA 64-bit
[    5.205765] idma64 idma64.7: Found Intel integrated DMA 64-bit
[    5.223336] Loading iSCSI transport class v2.0-870.
[    5.230905] nvme nvme0: pci function 0000:02:00.0
[    5.236434] nvme nvme1: pci function 0000:03:00.0
[    5.242121] ahci 0000:00:12.0: AHCI 0001.0301 32 slots 2 ports 6 Gbps 0x3 impl SATA mode
[    5.251285] ahci 0000:00:12.0: flags: 64bit ncq sntf clo only pmp pio slum part deso sadm sds apst 
[    5.270041] scsi host0: ahci
[    5.273840] scsi host1: ahci
[    5.277308] ata1: SATA max UDMA/133 abar m2048@0x9162c000 port 0x9162c100 irq 372
[    5.285708] ata2: SATA max UDMA/133 abar m2048@0x9162c000 port 0x9162c180 irq 372
[    5.341787]  nvme0n1: p1
[    5.348014]  nvme1n1: p1
[    5.596476] clocksource: Switched to clocksource tsc
[    5.598234] ata1: SATA link down (SStatus 0 SControl 300)
[    5.598244] ata1: Disk is not present for SATA link down event
[    5.905225] ata2: SATA link down (SStatus 0 SControl 300)
[    5.911269] ata2: Disk is not present for SATA link down event
[    5.919522] Change defer qc mode on external port for compatibility
[    5.926540] Change defer qc mode on external port for compatibility
[    5.933543] Change defer qc mode on external port for compatibility
[    5.951249] ahci 0000:01:00.0: AHCI 0001.0000 32 slots 4 ports 6 Gbps 0xf impl SATA mode
[    5.960298] ahci 0000:01:00.0: flags: 64bit ncq sntf led only pmp fbs pio slum part sxs 
[    5.973985] scsi host2: ahci
[    5.982139] scsi host3: ahci
[    5.989834] scsi host4: ahci
[    5.993260] ata3: SATA max UDMA/133 abar m2048@0x91500000 port 0x91500100 irq 379
[    6.001645] ata4: SATA max UDMA/133 abar m2048@0x91500000 port 0x91500180 irq 379
[    6.010018] ata5: SATA max UDMA/133 abar m2048@0x91500000 port 0x91500200 irq 379
[    6.323238] ata3: SATA link down (SStatus 0 SControl 300)
[    6.329282] ata3: Disk is not present for SATA link down event
[    6.640242] ata4: SATA link down (SStatus 0 SControl 300)
[    6.646283] ata4: Disk is not present for SATA link down event
[    6.957248] ata5: SATA link down (SStatus 0 SControl 300)
[    6.963280] ata5: No present pin info for SATA link down event
[    6.983013] rtc-s35390a i2c-RTC35390:00: rtc core: registered rtc-s35390a as rtc0
[    6.991451] i2c /dev entries driver
[    6.999570] i801_smbus 0000:00:1f.1: SMBus using polling
[    7.009593] md: raid1 personality registered for level 1
[    7.015707] NET: Registered protocol family 17
[    7.020736] Key type dns_resolver registered
[    7.027354] mce: Using 7 MCE banks
[    7.035600] registered taskstats version 1
[    7.040206] Loading compiled-in untrusted X.509 certificates
[    7.046549] Loading compiled-in X.509 certificates
[    7.051962] Loaded X.509 cert 'Synology SDG kernel module signing key: 7bd0b0d6bcd31651c22ce3978bdc8c8bdc417329'
[    7.065237] Loaded X.509 cert 'Synology Root Certification Authority: f2c075361f168425f8b5ef31b796406c3aab2089'
[    7.076550] Loaded X.509 cert 'Synology Kernel Module Signing Certification Authority: 600839b5d127e0e11d817a31f0575d323a7c0e28'
[    7.089511] Loaded X.509 cert 'Synology kernel module signing key: 4646ce54489669338118a3b1286da156ac366fa5'
[    7.100525] page_owner is disabled
[    7.104356] AppArmor: AppArmor sha1 policy hashing enabled
[    7.111554] rtc-s35390a i2c-RTC35390:00: setting system clock to 2022-06-15 00:06:44 UTC (1655251604)
[    7.124732] Freeing unused kernel memory: 916K
[    7.129701] Write protecting the kernel read-only data: 8192k
[    7.136473] Freeing unused kernel memory: 508K
[    7.142764] Freeing unused kernel memory: 300K
START /linuxrc.syno
START /linuxrc.syno.impl
Insert basic USB modules...
:: Loading module usb-common ... [  OK  ]
:: Loading module usbcore[    7.265905] ACPI: bus type USB registered
[    7.270437] usbcore: registered new interface driver usbfs
[    7.276614] usbcore: registered new interface driver hub
[    7.282601] usbcore: registered new interface driver ethub
[    7.288759] usbcore: registered new device driver usb
 ... [  OK  ]
:: Loading module xhci-hcd ... [  OK  ]
:: Loading module xhci-pci[    7.332544] xhci_hcd 0000:00:15.0: xHCI Host Controller
[    7.338417] xhci_hcd 0000:00:15.0: new USB bus registered, assigned bus number 1
[    7.547820] xhci_hcd 0000:00:15.0: hcc params 0x200077c1 hci version 0x100 quirks 0x01109010
[    7.557736] hub 1-0:1.0: USB hub found
[    7.561989] hub 1-0:1.0: 8 ports detected
[    7.566552] host 0000:00:15.0 port 1 has Vbus GPIO#11 with polarity ACTIVE_HIGH
[    7.575133] host 0000:00:15.0 port 3 has Vbus GPIO#13 with polarity ACTIVE_HIGH
[    7.584081] xhci_hcd 0000:00:15.0: xHCI Host Controller
[    7.589942] xhci_hcd 0000:00:15.0: new USB bus registered, assigned bus number 2
[    7.598301] usb usb2: We don't know the algorithms for LPM for this host, disabling LPM.
[    7.607703] hub 2-0:1.0: USB hub found
[    7.611955] hub 2-0:1.0: 7 ports detected
[    7.616523] host 0000:00:15.0 port 1 has Vbus GPIO#13 with polarity ACTIVE_HIGH
[    7.625050] host 0000:00:15.0 port 2 has Vbus GPIO#11 with polarity ACTIVE_HIGH
 ... [  OK  ]
Insert net driver(Mindspeed only)...
[    7.663126] apollolake_synobios: loading out-of-tree module taints kernel.
[    7.670823] apollolake_synobios: module license 'Synology Inc.' taints kernel.
[    7.678896] Disabling lock debugging due to kernel taint
[    7.696460] synobios open /dev/ttyS1 success
[    7.701439] correction with 0x00
[    7.706152] 2022-6-15 0:6:44 UTC
[    7.709763] synobios: load, major number 201
[    7.714537] Brand: Synology
[    7.717657] Model: DS-918+
[    7.720678] This is default settings: set group disks wakeup number to 1, spinup time deno 1
[    7.730119] synobios cpu_arch proc entry initialized
[    7.735669] synobios crypto_hw proc entry initialized
[    7.741313] synobios syno_platform proc entry initialized
Starting /usr/syno/bin/synocfgen...
/usr/syno/bin/synocfgen returns 0
[    7.756976] Module [apollolake_synobios] is removed. 
[    7.762685] synobios: unload
Exit on error [1] DISK NOT INSTALLED...
Wed Jun 15 00:06:44 UTC 2022
none /sys/kernel/debug debugfs rw,relatime 0 0
[    7.908263] usb 1-4: new high-speed USB device number 2 using xhci_hcd
umount: /etc/mtab: No such file or directory

linuxrc.syno failed on 1

starting pid 4502, tty '': '/etc/rc'
:: Starting /etc/rc
:: Mounting procfs ... [  OK  ]
:: Mounting tmpfs ... [  OK  ]
:: Mounting devtmpfs ... [  OK  ]
:: Mounting devpts ... [  OK  ]
:: Mounting sysfs ... [  OK  ]
[    8.276633] random: syno_swap_ctl: uninitialized urandom read (4 bytes read, 13 bits of entropy available)
:: Loading module fat ... [  OK  ]
:: Loading module vfat ... [  OK  ]
:: Loading module udp_tunnel ... [  OK  ]
:: Loading module ip6_udp_tunnel ... [  OK  ]
:: Loading module vxlan ... [  OK  ]
:: Loading module e1000e[    8.498948] e1000e: Intel(R) PRO/1000 Network Driver - 3.4.2.4-NAPI
[    8.505959] e1000e: Copyright(c) 1999 - 2019 Intel Corporation.
 ... [  OK  ]
:: Loading module i2c-algo-bit ... [  OK  ]
:: Loading module igb[    8.534791] Intel(R) Gigabit Ethernet Linux Driver - version 5.3.5.22
[    8.541988] Copyright(c) 2007 - 2018 Intel Corporation.
[    8.591555] igb 0000:04:00.0: added PHC on eth0
[    8.596631] igb 0000:04:00.0: Intel(R) Gigabit Ethernet Linux Driver
[    8.603748] igb 0000:04:00.0: eth0: (PCIe:2.5GT/s:Width x1) 
[    8.610084] igb 0000:04:00.0 eth0: MAC: 00:11:22:33:44:55
[    8.616128] igb 0000:04:00.0: eth0: PBA No: Unknown
[    8.621587] igb 0000:04:00.0: LRO is disabled
[    8.626464] igb 0000:04:00.0: Using MSI-X interrupts. 1 rx queue(s), 1 tx queue(s)
[    8.688360] igb 0000:05:00.0: added PHC on eth1
[    8.693447] igb 0000:05:00.0: Intel(R) Gigabit Ethernet Linux Driver
[    8.700561] igb 0000:05:00.0: eth1: (PCIe:2.5GT/s:Width x1) 
[    8.706890] igb 0000:05:00.0 eth1: MAC: 00:11:22:33:44:55
[    8.712936] igb 0000:05:00.0: eth1: PBA No: Unknown
[    8.718404] igb 0000:05:00.0: LRO is disabled
[    8.723282] igb 0000:05:00.0: Using MSI-X interrupts. 1 rx queue(s), 1 tx queue(s)
 ... [  OK  ]
:: Loading module r8168 ... [  OK  ]
:: Loading module sunrpc[    8.811441] RPC: Registered named UNIX socket transport module.
[    8.818082] RPC: Registered udp transport module.
[    8.823348] RPC: Registered tcp transport module.
[    8.828607] RPC: Registered tcp NFSv4.1 backchannel transport module.
 ... [  OK  ]
:: Loading module grace ... [  OK  ]
:: Loading module lockd ... [  OK  ]
:: Loading module nfs ... [  OK  ]
:: Loading module nfsv3 ... [  OK  ]
:: Loading module leds-lp3943 ... [  OK  ]
[    8.994494] synobios open /dev/ttyS1 success
[    8.999461] correction with 0x00
[    9.004099] 2022-6-15 0:6:46 UTC
[    9.007712] synobios: load, major number 201
[    9.012492] Brand: Synology
[    9.015612] Model: DS-918+
[    9.018635] This is default settings: set group disks wakeup number to 1, spinup time deno 1
[    9.028077] synobios cpu_arch proc entry initialized
[    9.033624] synobios crypto_hw proc entry initialized
[    9.039269] synobios syno_platform proc entry initialized
mknod: /dev/synobios: File exists
Starting SW init...
[    9.658883] Module [apollolake_synobios] is removed. 
[    9.664550] synobios: unload
:: Loading module synobios[    9.728505] synobios open /dev/ttyS1 success
[    9.733473] correction with 0x00
[    9.738141] 2022-6-15 0:6:46 UTC
[    9.741752] synobios: load, major number 201
[    9.746530] Brand: Synology
[    9.749648] Model: DS-918+
[    9.752668] This is default settings: set group disks wakeup number to 1, spinup time deno 1
[    9.762112] synobios cpu_arch proc entry initialized
[    9.767661] synobios crypto_hw proc entry initialized
[    9.773306] synobios syno_platform proc entry initialized
 ... [  OK  ]
udhcpc: started, v1.30.1
udhcpc: started, v1.30.1
eth0      Link encap:Ethernet  HWaddr 00:11:32:B4:CD:D7  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

eth1      Link encap:Ethernet  HWaddr 00:11:32:B4:CD:D8  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

:: Starting syslogd ... [  OK  ]
:: Starting scemd
:: Starting services in background
Starting findhostd in flash_rd...
Starting services in flash_rd...
Running /usr/syno/etc/rc.d/J01httpd.sh...
Starting httpd:80 in flash_rd...
Starting httpd:5000 in flash_rd...
Running /usr/syno/etc/rc.d/J03ssdpd.sh...
/usr/bin/minissdpd -i eth0 -i eth1
eth0 not RUNNING
eth1 not RUNNING
Running /usr/syno/etc/rc.d/J04synoagentregisterd.sh...
Starting synoagentregisterd...
Running /usr/syno/etc/rc.d/J30DisableNCQ.sh...
cat: can't open '/sys/block/sd*/device//model': No such file or directory
Running /usr/syno/etc/rc.d/J80ADTFanControl.sh...
Running /usr/syno/etc/rc.d/J98nbnsd.sh...
Starting nbnsd...
Running /usr/syno/etc/rc.d/J99avahi.sh...
Starting Avahi mDNS/DNS-SD Daemon
[   20.183863] random: avahi-daemon: uninitialized urandom read (4 bytes read, 31 bits of entropy available)
cname_load_conf failed:/var/tmp/nginx/avahi-aliases.conf
[   20.198865] random: avahi-daemon: uninitialized urandom read (8 bytes read, 31 bits of entropy available)
:: Loading module usb-storage[   20.267536] usb-storage 1-4:1.0: USB Mass Storage device detected
[   20.274562] scsi host5: usb-storage 1-4:1.0
[   20.279392] usbcore: registered new interface driver usb-storage
 ... [  OK  ]
:: Loading module hid ... [  OK  ]
:: Loading module usbhid[   20.310232] usbcore: registered new interface driver usbhid
[   20.316507] usbhid: USB HID core driver
 ... [  OK  ]
:: Loading module syno_hddmon[   21.143858] Syno_HddMon: Initialization completed.
 ... [  OK  ]
Excution Error

If you wait a bit (like 100 seconds) you'll see all of this too:

[   21.281658] scsi 5:0:0:0: Direct-Access     Synology DiskStation              DL17 PQ: 0 ANSI: 6
[   21.292410] sd 5:0:0:0: [synoboot] 245760 512-byte logical blocks: (126 MB/120 MiB)
[   21.302008] sd 5:0:0:0: [synoboot] Write Protect is off
[   21.308768] sd 5:0:0:0: [synoboot] No Caching mode page found
[   21.315208] sd 5:0:0:0: [synoboot] Assuming drive cache: write through
[   21.328859] GPT:Primary header thinks Alt. header is not at the end of the disk.
[   21.337139] GPT:239649 != 245759
[   21.340745] GPT:Alternate GPT header not at the end of the disk.
[   21.347459] GPT:239649 != 245759
[   21.351064] GPT: Use GNU Parted to correct GPT errors.
[   21.356819]  synoboot: synoboot1 synoboot2
[   21.364166] sd 5:0:0:0: [synoboot] Attached SCSI disk
[  100.286450] ext2: synoboot2 mounted, process=mantool
[  100.292742] random: nonblocking pool is initialized
[  100.341510] synoboot2 unmounted, process=mantool

And since it loads grub, let's see what is there

grub> ls
(hd0) (hd0,gpt2) (hd0,gpt1) (hd1) (hd1,msdos2) 

grub> ls (hd0,gpt1)/
efi/ grub_ver rd.gz zImage 

grub> ls (hd0,gpt2)/  
./ ../ grub_cksum.syno checksum.syno rd.gz vender zImage Sone.9 

grub> ls (hd1,msdos2)/
efi/ loader/ shellx64.efi arch/ shellia32.efi

This looks like, hd0,gpt1 is rescue /boot, hd0,gpt2 is normal /boot, and hd1,msdos2 is the EFI partition.

This is enough of a post for gaining serial access. Next up, figuring out how to install mainline linux.

A hint appears when powering off:

[11304.903498] synobios: power button pressed, ret = 0
The system is going down NOW!
Sent SIGKILL to all processes
[11309.306367] Module [usb_storage] is removed. 
rmmod usb_storage
[11309.314290] usbcore: deregistering interface driver usb-storage
Requesting system poweroff
[11314.234180] Turned off USB vbus gpio 13 (ACTIVE_HIGH)
[11314.740156] Turned off USB vbus gpio 13 (ACTIVE_HIGH)
[11315.246150] Turned off USB vbus gpio 11 (ACTIVE_HIGH)
[11315.752140] Turned off USB vbus gpio 11 (ACTIVE_HIGH)
[11315.901100] ACPI: Preparing to enter system sleep state S5
[11315.909650] reboot: Power down
[11315.916671] Confirm SLP_TYP poweroff status 0 pm1a 1c01 pm1b 1
[11315.933384] Confirm OS poweroff status 0 pm1a 3c01 pm1b 2001