I have built rootfs.ubi using buildroot 2012.11. On boot I'm not able to login to buildroot login prompt also. Linux is built with UBI and UBIFS support. Earlier I encountered this behaviour if rootfs was mounted as read-only due to some issues but now the logs doesn't mention read-only but behaves like one.

Can someone please direct me towards the problem?

Relevant log lines are as below:

Starting kernel ...

Booting Linux on physical CPU 0
Linux version 3.6.9 (root@hpro-wc-vm) (gcc version 4.6.3 (Sourcery CodeBench Lite 2012.03-57) ) #3 PREEMPT Fri Jun 24 17:14:18 IST 2016
Machine: Atmel SAMA5 (Device Tree), model: Atmel SAMA5D31-EK
AT91: Detected soc type: sama5d3
AT91: Detected soc subtype: sama5d31
AT91: sram at 0x300000 of 0x20000 mapped at 0xfef58000
Kernel command line: console=ttyS0,115200 earlyprintk mtdparts=atmel_nand:128k(img_selector),128k(uboot_env),128K(dtb_prim),128K(dtb_sec),2M(kernel_prim),2M(kernel_sec),40M(rootfs_prim),40M(rootfs_sec),-(user_data) ubi.mtd=7 root=ubi0_0 rw rootfstype=ubifs


9 cmdlinepart partitions found on MTD device atmel_nand
Creating 9 MTD partitions on "atmel_nand":
0x000000000000-0x000000020000 : "img_selector"
0x000000020000-0x000000040000 : "uboot_env"
0x000000040000-0x000000060000 : "dtb_prim"
0x000000060000-0x000000080000 : "dtb_sec"
0x000000080000-0x000000280000 : "kernel_prim"
0x000000280000-0x000000480000 : "kernel_sec"
0x000000480000-0x000002c80000 : "rootfs_prim"
0x000002c80000-0x000005480000 : "rootfs_sec"
0x000005480000-0x000008000000 : "user_data"
UBI: attaching mtd7 to ubi0
UBI: physical eraseblock size:   131072 bytes (128 KiB)
UBI: logical eraseblock size:    126976 bytes
UBI: smallest flash I/O unit:    2048
UBI: VID header offset:          2048 (aligned 2048)
UBI: data offset:                4096
UBI: max. sequence number:       0
UBI: volume 0 ("rootfs") re-sized from 106 to 310 LEBs
UBI: attached mtd7 to ubi0
UBI: MTD device name:            "rootfs_sec"
UBI: MTD device size:            40 MiB
UBI: number of good PEBs:        320
UBI: number of bad PEBs:         0
UBI: number of corrupted PEBs:   0
UBI: max. allowed volumes:       128
UBI: wear-leveling threshold:    4096
UBI: number of internal volumes: 1
UBI: number of user volumes:     1
UBI: available PEBs:             0
UBI: total number of reserved PEBs: 320
UBI: number of PEBs reserved for bad PEB handling: 6
UBI: max/mean erase counter: 1/1
UBI: image sequence number:  1458400647
UBI: background thread "ubi_bgt0d" started, PID 306
atmel_spi f0004000.spi: Using dma0chan1 (tx) and  dma0chan2 (rx) for DMA transfers
atmel_spi f0004000.spi: Atmel SPI Controller at 0xf0004000 (irq 18)
atmel_spi f0004000.spi: master is unqueued, this is deprecated
atmel_spi f8008000.spi: Using dma1chan0 (tx) and  dma1chan1 (rx) for DMA transfers
atmel_spi f8008000.spi: Atmel SPI Controller at 0xf8008000 (irq 26)
atmel_spi f8008000.spi: master is unqueued, this is deprecated
libphy: MACB_mii_bus: probed
macb f802c000.ethernet: eth0: Cadence MACB at 0xf802c000 irq 30 (00:0f:d4:06:d9:aa)
macb f802c000.ethernet: eth0: attached PHY driver [Generic PHY]         (mii_bus:phy_addr=f802c000.etherne:00, irq=-1)
at91_rtc fffffeb0.rtc: rtc core: registered fffffeb0.rtc as rtc0
AT91 Real Time Clock driver.
i2c /dev entries driver
TCP: cubic registered
NET: Registered protocol family 17
VFP support v0.3: implementor 41 architecture 2 part 30 variant 5 rev 1
at91_rtc fffffeb0.rtc: setting system clock to 2007-01-01 04:47:01 UTC (1167626821)
UBIFS: mounted UBI device 0, volume 0, name "rootfs"
UBIFS: file system size:   37965824 bytes (37076 KiB, 36 MiB, 299 LEBs)
UBIFS: journal size:       9023488 bytes (8812 KiB, 8 MiB, 72 LEBs)
UBIFS: media format:       w4/r0 (latest is w4/r0)
UBIFS: default compressor: lzo
UBIFS: reserved for root:  0 bytes (0 KiB)
VFS: Mounted root (ubifs filesystem) on device 0:10.
devtmpfs: mounted


grep: /proc/cmdline: No such file or directory
grep: /proc/cmdline: No such file or directory


awk: /proc/devices: No such file or directory

Please let me know if you need any further information


system/skeleton directory was found to be missing from buildroot source directory. Placing the skeleton and rebuilding rootfs solved the problem.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.