Mity CPU Platforms » MityDSP-L138 (ARM9 Based Platforms)

Hi,
We use the MityDSP-L138 in a factory automation product and need to prevent fs corruption from random shutdowns. My first attempt was to change the rootfs to read-only in a startup script, but it would be safer if the rootfs was read-only through power-up. I came across the Wiki page below and attempted to see how far I could go with this.

[[http://support.criticallink.com/redmine/projects/arm9-platforms/wiki/Configuring_a_Linux_Filesystem_for_Uncontrolled_Shutdowns]]

After implementing those changes, the root file system would still be rw after power-up. It finally came up as ro after the following changes.
1) Changed /etc/init.d/checkroot's rootmode to ro. However, I'm not sure if this is necessary.
2) Changed mtab to have rootfs as ro.

rootfs / auto ro 0 0
proc /proc proc rw 0 0
devpts /dev/pts devpts rw,mode=0620,gid=5 0 0
usbfs /proc/bus/usb usbfs rw 0 0
tmpfs /var/volatile tmpfs rw 0 0
tmpfs /dev/shm tmpfs rw,mode=0777 0 0
tmpfs /media/ram tmpfs rw 0 0
/dev/mtdblock1 /mnt/user_nand jffs2 rw,noatime,nodiratime 0 0

My fstab file is as follows -

# stock fstab - you probably want to override this with a machine specific one

rootfs               /                    auto       defaults,ro           1  1
proc                 /proc                proc       defaults              0  0
devpts               /dev/pts             devpts     mode=0620,gid=5       0  0
usbfs                /proc/bus/usb        usbfs      defaults              0  0
tmpfs                /var/volatile        tmpfs      defaults              0  0
tmpfs                /dev/shm             tmpfs      mode=0777             0  0
tmpfs                /media/ram           tmpfs      defaults              0  0

# uncomment this if your device has a SD/MMC/Transflash slot
#/dev/mmcblk0p1       /media/card          auto       defaults,sync,noauto  0  0

# mount TFS user nand partition
/dev/mtdblock1        /mnt/user_nand       jffs2     rw,noatime,nodiratime  0  0
#

With these changes it does power-up in readonly mode, but /mnt/user_nand is not actually mounted and thus, access to my application software that should be executed next. Rather, it falls through to the login prompt. I can manually mount /mnt/user_nand and access that partition. The goal is to have /mnt/user_nand be kept ro too and temporarily be changed to rw to update a configuration file.

Below is the power-up and you can see that there are other issues too. Is this the best approach to harden the filesystem?

U-Boot 2009.11 (Mar 31 2011 - 19:39:18)

I2C:   ready
DRAM:  128 MB
NAND:  256 MiB
MMC:   davinci: 0
In:    serial
Out:   serial
Err:   serial
ARM    Clock : 300000000 Hz
DDR    Clock : 150000000 Hz
EMIFA  CLock : 100000000 Hz
DSP    Clock : 300000000 Hz
ASYNC3 Clock : 150000000 Hz
Enet  config : 2
MMC 0 Enable : 0
Resetting ethernet phy
Net:   Ethernet PHY: GENERIC @ 0x03 [0x8]

Hit any key to stop autoboot:  0
8192 KiB M25P64 at 0:0 is now current device
## Booting kernel from Legacy Image at c0700000 ...
   Image Name:   Linux-2.6.34-rc1-14815-g0e16b7d
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    1981448 Bytes =  1.9 MB
   Load Address: c0008000
   Entry Point:  c0008000
   Verifying Checksum ... OK
   Loading Kernel Image ... OK
OK

 Starting kernel ...

Uncompressing Linux... done, booting the kernel.
Linux version 2.6.34-rc1-14815-g0e16b7d (mitydspl138@mitydspl138-desktop) (gcc version 4.3.3 (GCC) ) #4 PREEMPT Thu Nov 17 15:31:10 EST 2011
CPU: ARM926EJ-S [41069265] revision 5 (ARMv5TEJ), cr=00053177
CPU: VIVT data cache, VIVT instruction cache
Machine: MityDSP-L138
Peripheral Config Block Found
Enet_Config = 2
PHYMask = 0x8
No LCD Configured
UART[0] = 0, 0, 0, 115200
UART[1] = 1, 1, 0, 115200
UART[2] = 0, 0, 0, 115200
SPI[0] = 0, 0, 00, 0, 0
SPI[1] = 1, 1, 01, 0, 30000000
Memory policy: ECC disabled, Data cache writethrough
DaVinci da850/omap-l138 variant 0x0
Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 24384
Kernel command line: mem=96M console=ttyS1,115200n8 mtdparts=nand:128M(rootfs),-(userfs) ro root=/dev/mtdblock0 ro rootfstype=jffs2 ip=off
PID hash table entries: 512 (order: -1, 2048 bytes)
Dentry cache hash table entries: 16384 (order: 4, 65536 bytes)
Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)
Memory: 96MB = 96MB total
Memory: 93320k/93320k available, 4984k reserved, 0K highmem
Virtual kernel memory layout:
    vector  : 0xffff0000 - 0xffff1000   (   4 kB)
    fixmap  : 0xfff00000 - 0xfffe0000   ( 896 kB)
    DMA     : 0xff000000 - 0xffe00000   (  14 MB)
    vmalloc : 0xc6800000 - 0xfea00000   ( 898 MB)
    lowmem  : 0xc0000000 - 0xc6000000   (  96 MB)
    modules : 0xbf000000 - 0xc0000000   (  16 MB)
      .init : 0xc0008000 - 0xc002a000   ( 136 kB)
      .text : 0xc002a000 - 0xc039a000   (3520 kB)
      .data : 0xc03b4000 - 0xc03d69e0   ( 139 kB)
Experimental preemptable hierarchical RCU implementation.
NR_IRQS:245
Console: colour dummy device 80x30
Calibrating delay loop... 149.50 BogoMIPS (lpj=747520)
Mount-cache hash table entries: 512
CPU: Testing write buffer coherency: ok
DaVinci: 144 gpio irqs
regulator: core version 0.5
NET: Registered protocol family 16
mityomapl138_init...
mityomapl138_setup_nand: using 16 bit data
EMAC: MII PHY configured, RMII PHY will not be functional
mityomapl138_init: setting phy_mask to 8
mityomapl138_init: no LCD device enabled
bio: create slab <bio-0> at 0
SCSI subsystem initialized
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
regulator: VDCDC1: 1150 <--> 1350 mV at 1200 mV
regulator: VDCDC2: 1710 <--> 1910 mV at 3300 mV
regulator: VDCDC3: 1120 <--> 1320 mV at 1800 mV
regulator: LDO1: 1800 mV
regulator: LDO2: 3300 mV
Switching to clocksource timer0_1
NET: Registered protocol family 2
IP route cache hash table entries: 1024 (order: 0, 4096 bytes)
TCP established hash table entries: 4096 (order: 3, 32768 bytes)
TCP bind hash table entries: 4096 (order: 2, 16384 bytes)
TCP: Hash tables configured (established 4096 bind 4096)
TCP reno registered
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 udp transport module.
RPC: Registered tcp transport module.
RPC: Registered tcp NFSv4.1 backchannel transport module.
JFFS2 version 2.2. (NAND) © 2001-2006 Red Hat, Inc.
msgmni has been set to 182
io scheduler noop registered (default)
Serial: 8250/16550 driver, 3 ports, IRQ sharing disabled
serial8250.0: ttyS0 at MMIO 0x1c42000 (irq = 25) is a 16550A
serial8250.0: ttyS1 at MMIO 0x1d0c000 (irq = 53) is a 16550A
console [ttyS1] enabled
serial8250.0: ttyS2 at MMIO 0x1d0d000 (irq = 61) is a 16550A
brd: module loaded
at24 1-0050: 256 byte 24c02 EEPROM (read-only)
MityOMAPL138: Found MAC = 00:50:c2:bf:89:7f
MityOMAPL138: Part Number = L138-CG-225-Rc
MityOMAPL138: setting max frequency to 300 MHz
ahci ahci: forcing PORTS_IMPL to 0x1
ahci ahci: AHCI 0001.0100 32 slots 1 ports 3 Gbps 0x1 impl SATA mode
ahci ahci: flags: ncq sntf pm led clo only pmp pio slum part ccc
scsi0 : ahci
ata1: SATA max UDMA/133 irq 67
NAND device: Manufacturer ID: 0x2c, Chip ID: 0xca (Micron NAND 256MiB 3,3V 16-bit)
Creating 2 MTD partitions on "davinci_nand.1":
0x000000000000-0x000008000000 : "rootfs" 
0x000008000000-0x000010000000 : "homefs" 
davinci_nand davinci_nand.1: controller rev. 2.5
spi_davinci spi_davinci.1: Controller at 0xfef0e000
console [netcon0] enabled
netconsole: network logging started
ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
ohci ohci.0: DA8xx OHCI
ohci ohci.0: new USB bus registered, assigned bus number 1
Waiting for USB PHY clock good...
ohci ohci.0: irq 59, io mem 0x01e25000
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 1 port detected
omap_rtc omap_rtc: rtc core: registered omap_rtc as rtc0
omap_rtc: RTC power up reset detected
omap_rtc: already running
i2c /dev entries driver
watchdog watchdog: heartbeat 60 sec
cpuidle: using governor ladder
cpuidle: using governor menu
davinci_mmc davinci_mmc.0: Using DMA, 4-bit mode
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
TCP cubic registered
NET: Registered protocol family 17
Clocks: disable unused i2c1
Clocks: disable unused emac
Clocks: disable unused mcasp
Clocks: disable unused lcdc
Clocks: disable unused spi0
Clocks: disable unused mcbsp0
Clocks: disable unused mcbsp1
Clocks: disable unused vpif
regulator_init_complete: incomplete constraints, leaving LDO2 on
regulator_init_complete: incomplete constraints, leaving LDO1 on
regulator_init_complete: incomplete constraints, leaving VDCDC3 on
regulator_init_complete: incomplete constraints, leaving VDCDC2 on
regulator_init_complete: incomplete constraints, leaving VDCDC1 on
emac-mii: probed
omap_rtc omap_rtc: setting system clock to 2012-07-20 17:56:18 UTC (1342806978)
ata1: SATA link down (SStatus 0 SControl 300)
Empty flash at 0x012306a0 ends at 0x01230800
Empty flash at 0x03d2d190 ends at 0x03d2d800
Empty flash at 0x03d350d0 ends at 0x03d35800
jffs2_scan_inode_node(): CRC failed on node at 0x0401efc4: Read 0xffffffff, calculated 0x6f615b7a
Empty flash at 0x0401f0e8 ends at 0x0401f800
VFS: Mounted root (jffs2 filesystem) readonly on device 31:0.
Freeing init memory: 136K
INIT: version 2.86 booting
Please wait: booting...
Starting udev
Remounting root file system...
Caching udev devnodes
rm: cannot remove '/etc/volatile.cache': Read-only file system
chown: /var/volatile/cache: Read-only file system
chmod: /var/volatile/cache: Read-only file system
chown: /var/volatile/lock: Read-only file system
chmod: /var/volatile/lock: Read-only file system
chown: /var/volatile/log: Read-only file system
chmod: /var/volatile/log: Read-only file system
chown: /var/volatile/run: Read-only file system
chmod: /var/volatile/run: Read-only file system
chown: /var/volatile/tmp: Read-only file system
chmod: /var/volatile/tmp: Read-only file system
touch: /var/log/wtmp: Read-only file system
chown: /var/lock/subsys: Read-only file system
chmod: /var/lock/subsys: Read-only file system
touch: /var/log/lastlog: Read-only file system
chown: /var/log/wtmp: No such file or directory
chown: /var/log/lastlog: No such file or directory
chmod: /var/log/wtmp: No such file or directory
chmod: /var/log/lastlog: No such file or directory
touch: /var/run/utmp: Read-only file system
chown: /var/run/utmp: Read-only file system
chmod: /var/run/utmp: Read-only file system
touch: /var/run/resolv.conf: Read-only file system
touch: /var/run/resolv.conf: Read-only file system
chown: /var/run/resolv.conf: No such file or directory
chmod: /var/run/resolv.conf: No such file or directory
chown: /var/run/resolv.conf: No such file or directory
chmod: /var/run/resolv.conf: No such file or directory
Configuring network interfaces... ifup: can't open '/var/run/ifstate': Read-only file system
done.
Starting portmap daemon: portmap.
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.all.rp_filter = 1
INIT: Entering runlevel: 5
mkdir: cannot create directory '/var/run/dbus': Read-only file system
mkdir: cannot create directory '/var/volatile/dropbear': Read-only file system
creating NFS state directory: /etc/rc5.d/S20nfsserver: line 149: can't create sm/state: Read-only file system
done
starting 8 nfsd kernel threads: done
starting mountd: done
starting statd: done
Starting syslogd/klogd: done
 * Starting Avahi mDNS/DNS-SD Daemon: avahi-daemon
Timeout reached while wating for return value
Could not receive return value from daemon process.
   ...fail!

Starting my configuration
/etc/rc5.d/S95_my_startup: line 20: ./init_network: not found
/etc/rc5.d/S95_my_startup: line 22: ./start: not found
Now Starting my application
/etc/rc5.d/S95_my_startup: line 26: ./sensor: not found

Sensor startup has completed!

.-------.
|       |                  .-.
|   |   |-----.-----.-----.| |   .----..-----.-----.
|       |     | __  |  ---'| '--.|  .-'|     |     |
|   |   |  |  |     |---  ||  --'|  |  |  '  | | | |
'---'---'--'--'--.  |-----''----''--'  '-----'-'-'-'
                -'  |
                '---'

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