我正在关注Bootlin's embedded Linux training，其目标是将嵌入式Linux系统放在Atmel SAMA5D4 Xplained board（theory slides，practical lab instructions）上，而我坚持将整个系统放在NAND闪存。
他们要求我将DTB，内核，根文件系统和数据文件系统放入要写入闪存的UBI映像中，但是一旦将其刷新，我将无法访问UBI分区（访问失败，错误代码22 ，或在嵌入式Linux环境中为-22。
（要查看我的实际问题，请转到问题的结尾）
在U-Boot中，分区由mtdparts定义：
device nand0 <atmel_nand>, # parts = 8
#: name size offset mask_flags
0: bootstrap 0x00040000 0x00000000 1
1: uboot 0x00080000 0x00040000 1
2: env 0x00040000 0x000c0000 1
3: envbackup 0x00040000 0x00100000 1
4: dtb 0x00020000 0x00140000 0
5: kernel 0x00500000 0x00160000 0
6: rootfs 0x01000000 0x00660000 0
7: datafs 0x01000000 0x01660000 0
active partition: nand0,0 - (bootstrap) 0x00040000 @ 0x00000000
defaults:
mtdids :
mtdparts:
有了printenv mtdparts，我得到：
mtdparts=mtdparts=atmel_nand:256k(bootstrap)ro,512k(uboot)ro,256k(env)ro,256k(envbackup)ro,128k(dtb),5M(kernel),16M(rootfs),16M(datafs)
和printenv mtdids
mtdids=nand0=atmel_nand
UBI映像是使用ubinize和以下配置创建的：
[dtb]
peb=0x20000
min_io_size=0x800
mode=ubi
image=dtb.img
vol_id=0
vol_size=128KiB
vol_type=static
vol_name=dtb
vol_alignment=1
[kernel]
peb=0x20000
min_io_size=0x800
mode=ubi
image=zImage
vol_id=1
vol_size=5MiB
vol_type=static
vol_name=kernel
vol_alignment=1
[rootfs]
peb=0x20000
min_io_size=0x800
mode=ubi
image=root.img
vol_id=2
vol_size=16MiB
vol_type=static
vol_name=rootfs
vol_alignment=1
[datafs]
peb=0x20000
min_io_size=0x800
mode=ubi
image=files.img
vol_id=3
vol_size=16MiB
vol_type=static
vol_name=datafs
vol_alignment=1
和此命令（sama5-ubinize.cfg是上面的配置）
ubinize -o ubi.img -p 128KiB -m 2KiB sama5-ubinize.cfg
PEB确实为128KB（0x2000），页面大小为2048B（0x800）。我根据this answer添加了这些参数。
两个UBI分区都使用以下命令创建：
mkfs.ubifs -e 124KiB -c 132 -m 2KiB -r nfsroot/ root.img
mkfs.ubifs -e 124KiB -c 132 -m 2KiB -r nfsroot/www/upload/files data.img
然后我使用以下命令（在U-Boot中）将UBI映像写入闪存：
nand erase 0x140000 0xfec0000
tftp 0x21000000 ubi.img
nand write.trimffs 0x21000000 0x140000 0x880000
尝试使用ubi part rootfs从U-Boot访问分区时，出现以下错误：
ubi0: attaching mtd1
ubi0: scanning is finished
UBI init error 22
目前，我正在从SD卡引导Linux。 Linux引导参数为（来自printenv bootargs）：
bootargs=console=ttyS0,115200 root=/dev/mmcblk0p2 rw rootwait
启动Linux时，出现以下日志：
resetting ...
RomBOOT
AT91Bootstrap 3.8.9 (Mi Dez 12 21:06:49 CET 2018)
NAND: ONFI flash detected
NAND: Manufacturer ID: 0x2c Chip ID: 0xda
NAND: Page Bytes: 2048, Spare Bytes: 64
NAND: ECC Correctability Bits: 4, ECC Sector Bytes: 512
NAND: Disable On-Die ECC
NAND: Initialize PMECC params, cap: 4, sector: 512
NAND: Image: Copy 0xa0000 bytes from 0x40000 to 0x26f00000
NAND: Done to load image
<debug_uart>
U-Boot 2017.09 (Dec 12 2018 - 23:16:12 +0100)
CPU: SAMA5D36
Crystal frequency: 12 MHz
CPU clock : 528 MHz
Master clock : 132 MHz
DRAM: 256 MiB
NAND: 256 MiB
MMC: Atmel mci: 0, Atmel mci: 1
In: serial@ffffee00
Out: serial@ffffee00
Err: serial@ffffee00
Net: eth0: ethernet@f0028000
Error: ethernet@f802c000 address not set.
Hit any key to stop autoboot: 0
reading zImage
4279056 bytes read in 281 ms (14.5 MiB/s)
reading at91-sama5d3_xplained.dtb
34404 bytes read in 7 ms (4.7 MiB/s)
## Flattened Device Tree blob at 22000000
Booting using the fdt blob at 0x22000000
Loading Device Tree to 2fb39000, end 2fb44663 ... OK
Starting kernel ...
Booting Linux on physical CPU 0x0
Linux version 4.18.20 (dopsi@dopsi-ThinkPad-T430) (gcc version 8.1.0 (crosstool-NG 1.23.0.435-eb65)) #4 Sat Dec 15 14:07:41 CET 2018
CPU: ARMv7 Processor [410fc051] revision 1 (ARMv7), cr=10c53c7d
CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
OF: fdt: Machine model: SAMA5D3 Xplained
Memory policy: Data cache writeback
CPU: All CPU(s) started in SVC mode.
random: get_random_bytes called from start_kernel+0x9c/0x3d8 with crng_init=0
Built 1 zonelists, mobility grouping on. Total pages: 65024
Kernel command line: console=ttyS0,115200 root=/dev/mmcblk0p2 rw rootwait
Dentry cache hash table entries: 32768 (order: 5, 131072 bytes)
Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
Memory: 250120K/262144K available (6144K kernel code, 237K rwdata, 1588K rodata, 1024K init, 124K bss, 12024K reserved, 0K cma-reserved)
Virtual kernel memory layout:
vector : 0xffff0000 - 0xffff1000 ( 4 kB)
fixmap : 0xffc00000 - 0xfff00000 (3072 kB)
vmalloc : 0xd0800000 - 0xff800000 ( 752 MB)
lowmem : 0xc0000000 - 0xd0000000 ( 256 MB)
modules : 0xbf000000 - 0xc0000000 ( 16 MB)
.text : 0x(ptrval) - 0x(ptrval) (7136 kB)
.init : 0x(ptrval) - 0x(ptrval) (1024 kB)
.data : 0x(ptrval) - 0x(ptrval) ( 238 kB)
.bss : 0x(ptrval) - 0x(ptrval) ( 125 kB)
NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16
clocksource: pit: mask: 0xfffffff max_cycles: 0xfffffff, max_idle_ns: 14479245754 ns
sched_clock: 32 bits at 100 Hz, resolution 10000000ns, wraps every 21474836475000000ns
Console: colour dummy device 80x30
Calibrating delay loop... 351.43 BogoMIPS (lpj=1757184)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
CPU: Testing write buffer coherency: ok
Setting up static identity map for 0x20100000 - 0x20100060
devtmpfs: initialized
VFP support v0.3: implementor 41 architecture 2 part 30 variant 5 rev 1
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
futex hash table entries: 256 (order: -1, 3072 bytes)
pinctrl core: initialized pinctrl subsystem
NET: Registered protocol family 16
DMA: preallocated 256 KiB pool for atomic coherent allocations
AT91: PM: standby: standby, suspend: ulp0
No ATAGs?
gpio-at91 fffff200.gpio: at address (ptrval)
gpio-at91 fffff400.gpio: at address (ptrval)
gpio-at91 fffff600.gpio: at address (ptrval)
gpio-at91 fffff800.gpio: at address (ptrval)
gpio-at91 fffffa00.gpio: at address (ptrval)
pinctrl-at91 ahb:apb:pinctrl@fffff200: initialized AT91 pinctrl driver
clocksource: tcb_clksrc: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 115833966437 ns
at_hdmac ffffe600.dma-controller: Atmel AHB DMA Controller ( cpy set slave ), 8 channels
at_hdmac ffffe800.dma-controller: Atmel AHB DMA Controller ( cpy set slave ), 8 channels
AT91: Detected SoC family: sama5d3
AT91: Detected SoC: sama5d36, revision 2
SCSI subsystem initialized
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
at91_i2c f0014000.i2c: using dma0chan0 (tx) and dma0chan1 (rx) for DMA transfers
at91_i2c f0014000.i2c: AT91 i2c bus driver (hw version: 0x402).
at91_i2c f0018000.i2c: using dma0chan2 (tx) and dma0chan3 (rx) for DMA transfers
at91_i2c f0018000.i2c: AT91 i2c bus driver (hw version: 0x402).
at91_i2c f801c000.i2c: can't get DMA channel, continue without DMA support
at91_i2c f801c000.i2c: AT91 i2c bus driver (hw version: 0x402).
videodev: Linux video capture interface: v2.00
pps_core: LinuxPPS API ver. 1 registered
pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti <giometti@linux.it>
PTP clock support registered
Advanced Linux Sound Architecture Driver Initialized.
clocksource: Switched to clocksource tcb_clksrc
NET: Registered protocol family 2
tcp_listen_portaddr_hash hash table entries: 512 (order: 0, 4096 bytes)
TCP established hash table entries: 2048 (order: 1, 8192 bytes)
TCP bind hash table entries: 2048 (order: 1, 8192 bytes)
TCP: Hash tables configured (established 2048 bind 2048)
UDP hash table entries: 256 (order: 0, 4096 bytes)
UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
NET: Registered protocol family 1
RPC: Registered named UNIX socket transport module.
RPC: Registered udp transport module.
RPC: Registered tcp transport module.
RPC: Registered tcp NFSv4.1 backchannel transport module.
Initialise system trusted keyrings
workingset: timestamp_bits=30 max_order=16 bucket_order=0
squashfs: version 4.0 (2009/01/31) Phillip Lougher
Key type asymmetric registered
Asymmetric key parser 'x509' registered
io scheduler noop registered (default)
io scheduler mq-deadline registered
io scheduler kyber registered
f001c000.serial: ttyS1 at MMIO 0xf001c000 (irq = 23, base_baud = 4125000) is a ATMEL_SERIAL
f0020000.serial: ttyS2 at MMIO 0xf0020000 (irq = 24, base_baud = 4125000) is a ATMEL_SERIAL
f0024000.serial: ttyS5 at MMIO 0xf0024000 (irq = 25, base_baud = 4125000) is a ATMEL_SERIAL
ffffee00.serial: ttyS0 at MMIO 0xffffee00 (irq = 38, base_baud = 8250000) is a ATMEL_SERIAL
console [ttyS0] enabled
brd: module loaded
loop: module loaded
atmel_spi f0004000.spi: Using dma0chan4 (tx) and dma0chan5 (rx) for DMA transfers
atmel_spi f0004000.spi: Atmel SPI Controller version 0x213 at 0xf0004000 (irq 19)
atmel_spi f8008000.spi: Using dma1chan0 (tx) and dma1chan1 (rx) for DMA transfers
atmel_spi f8008000.spi: Atmel SPI Controller version 0x213 at 0xf8008000 (irq 28)
libphy: Fixed MDIO Bus: probed
CAN device driver interface
at91_can f000c000.can: device registered (reg_base=(ptrval), irq=45)
libphy: MACB_mii_bus: probed
Micrel KSZ9031 Gigabit PHY f0028000.ethernet-ffffffff:07: attached PHY driver [Micrel KSZ9031 Gigabit PHY] (mii_bus:phy_addr=f0028000.ethernet-ffffffff:07, irq=POLL)
macb f0028000.ethernet eth0: Cadence GEM rev 0x00020119 at 0xf0028000 irq 46 (12:34:56:ab:cd:ef)
macb f802c000.ethernet: invalid hw address, using random
libphy: MACB_mii_bus: probed
Micrel KSZ8081 or KSZ8091 f802c000.ethernet-ffffffff:01: attached PHY driver [Micrel KSZ8081 or KSZ8091] (mii_bus:phy_addr=f802c000.ethernet-ffffffff:01, irq=POLL)
macb f802c000.ethernet eth1: Cadence MACB rev 0x0001010c at 0xf802c000 irq 47 (62:aa:eb:b7:c1:48)
ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
ehci-atmel: EHCI Atmel driver
atmel-ehci 700000.ehci: EHCI Host Controller
atmel-ehci 700000.ehci: new USB bus registered, assigned bus number 1
atmel-ehci 700000.ehci: irq 50, io mem 0x00700000
atmel-ehci 700000.ehci: USB 2.0 started, EHCI 1.00
usb usb1: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 4.18
usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
usb usb1: Product: EHCI Host Controller
usb usb1: Manufacturer: Linux 4.18.20 ehci_hcd
usb usb1: SerialNumber: 700000.ehci
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 3 ports detected
ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
ohci-atmel: OHCI Atmel driver
at91_ohci 600000.ohci: USB Host Controller
at91_ohci 600000.ohci: new USB bus registered, assigned bus number 2
at91_ohci 600000.ohci: irq 50, io mem 0x00600000
usb usb2: New USB device found, idVendor=1d6b, idProduct=0001, bcdDevice= 4.18
usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
usb usb2: Product: USB Host Controller
usb usb2: Manufacturer: Linux 4.18.20 ohci_hcd
usb usb2: SerialNumber: at91
hub 2-0:1.0: USB hub found
hub 2-0:1.0: 3 ports detected
usbcore: registered new interface driver cdc_acm
cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters
usbcore: registered new interface driver usb-storage
usbcore: registered new interface driver usbserial_generic
usbserial: USB Serial support registered for generic
usbcore: registered new interface driver ftdi_sio
usbserial: USB Serial support registered for FTDI USB Serial Device
usbcore: registered new interface driver pl2303
usbserial: USB Serial support registered for pl2303
atmel_usba_udc 500000.gadget: MMIO registers at [mem 0xf8030000-0xf8033fff] mapped at (ptrval)
atmel_usba_udc 500000.gadget: FIFO at [mem 0x00500000-0x005fffff] mapped at (ptrval)
g_serial gadget: Gadget Serial v2.4
g_serial gadget: g_serial ready
at91_rtc fffffeb0.rtc: registered as rtc0
at91_rtc fffffeb0.rtc: AT91 Real Time Clock driver.
i2c /dev entries driver
at91-reset fffffe00.rstc: Starting after software reset
sdhci: Secure Digital Host Controller Interface driver
sdhci: Copyright(c) Pierre Ossman
atmel_mci f0000000.mmc: version: 0x505
atmel_mci f0000000.mmc: using dma0chan6 for DMA transfers
atmel_mci f0000000.mmc: Atmel MCI controller at 0xf0000000 irq 18, 1 slots
atmel_mci f8000000.mmc: version: 0x505
atmel_mci f8000000.mmc: using dma1chan2 for DMA transfers
atmel_mci f8000000.mmc: Atmel MCI controller at 0xf8000000 irq 27, 1 slots
sdhci-pltfm: SDHCI platform and OF driver helper
atmel_aes f8038000.aes: version: 0x135
atmel_aes f8038000.aes: Atmel AES - Using dma1chan3, dma1chan4 for DMA transfers
atmel_sha f8034000.sha: version: 0x410
atmel_sha f8034000.sha: using dma1chan5 for DMA transfers
atmel_sha f8034000.sha: Atmel SHA1/SHA256/SHA224/SHA384/SHA512
atmel_tdes f803c000.tdes: version: 0x701
atmel_tdes f803c000.tdes: using dma1chan6, dma1chan7 for DMA transfers
mmc0: host does not support reading read-only switch, assuming write-enable
mmc0: new high speed SDHC card at address b368
mmcblk0: mmc0:b368 SD4GB 3.74 GiB
mmcblk0: p1 p2 p3
atmel_tdes f803c000.tdes: Atmel DES/TDES
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xda
nand: Micron MT29F2G08ABAEAWP
nand: 256 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
Bad block table found at page 131008, version 0x01
Bad block table found at page 130944, version 0x01
nand_read_bbt: bad block at 0x000000c80000
nand_read_bbt: bad block at 0x000000ca0000
6 fixed-partitions partitions found on MTD device atmel_nand
Creating 6 MTD partitions on "atmel_nand":
0x000000000000-0x000000040000 : "at91bootstrap"
0x000000040000-0x0000000c0000 : "bootloader"
0x0000000c0000-0x000000180000 : "bootloader env"
0x000000180000-0x000000200000 : "device tree"
0x000000200000-0x000000800000 : "kernel"
0x000000800000-0x000010000000 : "rootfs"
iio iio:device0: Resolution used: 12 bits
iio iio:device0: ADC Touch screen is disabled.
NET: Registered protocol family 10
Segment Routing with IPv6
sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
NET: Registered protocol family 17
can: controller area network core (rev 20170425 abi 9)
NET: Registered protocol family 29
can: raw protocol (rev 20170425)
can: broadcast manager protocol (rev 20170425 t)
can: netlink gateway (rev 20170425) max_hops=1
Loading compiled-in X.509 certificates
input: gpio_keys as /devices/platform/gpio_keys/input/input0
at91_rtc fffffeb0.rtc: setting system clock to 2007-01-01 01:05:49 UTC (1167613549)
cfg80211: Loading compiled-in X.509 certificates for regulatory database
cfg80211: Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
ALSA device list:
No soundcards found.
platform regulatory.0: Direct firmware load for regulatory.db failed with error -2
g_serial gadget: high-speed config #2: CDC ACM config
random: fast init done
cfg80211: failed to load regulatory.db
VFS: Mounted root (squashfs filesystem) readonly on device 179:2.
devtmpfs: mounted
Freeing unused kernel memory: 1024K
starting pid 761, tty '': '/etc/init.d/rcS'
EXT4-fs (mmcblk0p3): recovery complete
EXT4-fs (mmcblk0p3): mounted filesystem with ordered data mode. Opts: (null)
starting pid 768, tty '/dev/ttyS0': '/bin/sh'
BusyBox v1.29.3 (2018-12-15 12:27:14 CET) built-in shell (ash)
Enter 'help' for a list of built-in commands.
它检测到一个分区以外的所有分区，但是我也无法访问它们。尝试附加任何一个（使用ubiattach -m 5 /dev/ubi_ctrl）时，出现以下错误（所有分区号的错误均相同）：
ubi0: attaching mtd5
ubi0: scanning is finished
ubi0 error: ubi_read_volume_table: the layout volume was not found
ubi0 error: ubi_attach_mtd_dev: failed to attach mtd5, error -22
ubiattach: UBI_IOCATT: Invalid argument
答案 0 :(得分：2)
感谢很好描述的问题。很高兴在这种情况下为您提供帮助：）
有些事情看起来不正确，或者至少不符合Bootlin实验室的精神。
这肯定会有所帮助。如果这样做之后仍然遇到问题，请不要犹豫再回来。
开心地学习和学习
Michael（来自Bootlin）
答案 1 :(得分：0)
我提出了另一条线索作为后续行动 bootlin kernel doesn't boot from UBIFS
希望迈克尔也可以对其进行审查