用的是TI的 816X开发板，现在碰到一个问题，想不明白，请教各位。
我的开发环境是在vmware下安装的ubuntu10.04，通过网线连接到开发板的网口（J10),主机IP为192.168.0.11 ，开发板IP为192.168.0.12
从SD卡启动后，在u-boot命令行下，将SD卡内自带的内核文件uimage下载到内存0x81000000处，过程如下：
mmc init 0
fatload mmc 0 0x81000000 uimage
下载完成后设置环境变量如下：
setenv bootargs 'console =ttyO2,115200n8 rootwait root=/dev/nfs rw nfsroot=192.168.0.11:/home/sony/targetfs mem=256M earlyprintk vram=50M ti816xfb.vram=0:16M,2:6M ip= 192.168.0.12:192.168.0.11:192.168.0.1:255.255.255.0::eth0:off noinitrd'
setenv ipaddr 192.168.0.12
setenv serverip 192.168.0.11
bootm 0x81000000后nfs可以挂载根文件系统。
如果是把SD卡内的uimage拷贝到虚拟机的共享目录下，通过linux和windows共享文件的方式，把uimage放在linux的tftp目录下
还是通过SD卡启动，在u-boot命令行下通过tftp方式下载uimage到内存0x81000000处，再bootm 0x81000000则挂载根文件系统失败。
我比较过两个uimage文件，大小一样，内容我对比了一下头尾处，也是一样的。
对比了两种方式的log信息，除NFS挂载失败处不一样外，其他也是一样的，请问可能是什么原因造成这种区别呢？
打印信息如下：
bootm 0x81000000
## Booting kernel from Legacy Image at 81000000 ...
Image Name: Arago/2.6.37-psp04.00.00.10/dm81
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 2362080 Bytes = 2.3 MiB
Load Address: 80008000
Entry Point: 80008000
Verifying Checksum ... OK
Loading Kernel Image ... OK
OK
Starting kernel ...
Uncompressing Linux... done, booting the kernel.
Linux version 2.6.37 (x0029463@swubn01) (gcc version 4.3.3 (Sourcery G++ Lite 2009q1-203) ) #1 Wed Jun 1 12:18:59 IST 2011
CPU: ARMv7 Processor [413fc082] revision 2 (ARMv7), cr=10c53c7f
CPU: VIPT nonaliasing data cache, VIPT aliasing instruction cache
Machine: ti8168evm
bootconsole [earlycon0] enabled
vram size = 52428800 at 0
reserved size = 52428800 at 0
FB: Reserving 52428800 bytes SDRAM for VRAM
Memory policy: ECC disabled, Data cache writeback
OMAP chip is TI8168 1.1
Built 1 zonelists in Zone order, mobility grouping on. Total pages: 52224
Kernel command line: console=ttyO2,115200n8 rootwait root=/dev/nfs rw nfsroot=192.168.0.11:/home/sony/targetfs mem=256M earlyprintk vram=50M ti816xfb.vram=0:16M,2:6M ip=192.168.0.12:192.168.0.11:192.168.0.1:255.255.255.0::eth0:off noinitrd
PID hash table entries: 1024 (order: 0, 4096 bytes)
Dentry cache hash table entries: 32768 (order: 5, 131072 bytes)
Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
Memory: 206MB = 206MB total
Memory: 203604k/203604k available, 58540k reserved, 0K highmem
Virtual kernel memory layout:
vector : 0xffff0000 - 0xffff1000 ( 4 kB)
fixmap : 0xfff00000 - 0xfffe0000 ( 896 kB)
DMA : 0xffc00000 - 0xffe00000 ( 2 MB)
vmalloc : 0xd0800000 - 0xf8000000 ( 632 MB)
lowmem : 0xc0000000 - 0xd0000000 ( 256 MB)
modules : 0xbf000000 - 0xc0000000 ( 16 MB)
.init : 0xc0008000 - 0xc0035000 ( 180 kB)
.text : 0xc0035000 - 0xc0478000 (4364 kB)
.data : 0xc0478000 - 0xc04b91e0 ( 261 kB)
SLUB: Genslabs=11, HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
NR_IRQS:407
IRQ: Found an INTC at 0xfa200000 (revision 5.0) with 128 interrupts
Total of 128 interrupts on 1 active controller
GPMC revision 6.0
Trying to install interrupt handler for IRQ400
Trying to install interrupt handler for IRQ401
Trying to install interrupt handler for IRQ402
Trying to install interrupt handler for IRQ403
Trying to install interrupt handler for IRQ404
Trying to install interrupt handler for IRQ405
Trying to install interrupt handler for IRQ406
Trying to install type control for IRQ407
Trying to set irq flags for IRQ407
OMAP clockevent source: GPTIMER1 at 27000000 Hz
Console: colour dummy device 80x30
Calibrating delay loop... 986.31 BogoMIPS (lpj=4931584)
pid_max: default: 32768 minimum: 301
Security Framework initialized
Mount-cache hash table entries: 512
CPU: Testing write buffer coherency: ok
devtmpfs: initialized
omap_voltage_early_init: voltage driver support not added
regulator: core version 0.5
regulator: dummy:
NET: Registered protocol family 16
OMAP GPIO hardware version 0.1
OMAP GPIO hardware version 0.1
omap_mux_init: Add partition: #1: core, flags: 0
_omap_mux_get_by_name: Could not find signal i2c2_scl.i2c2_scl
_omap_mux_get_by_name: Could not find signal i2c2_sda.i2c2_sda
NOR: Can't request GPMC CS
registered ti816x_vpss device
pm_dbg_init: only OMAP3 supported
Registered ti81xx_fb device
ti816x_pcie: Invoking PCI BIOS...
ti816x_pcie: Setting up Host Controller...
ti816x_pcie: Register base mapped @0xd0820000
ti816x_pcie: Starting PCI scan...
PCI: bus0: Fast back to back transfers enabled
bio: create slab <bio-0> at 0
vgaarb: loaded
SCSI subsystem initialized
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
omap_i2c omap_i2c.1: bus 1 rev4.0 at 100 kHz
omap_i2c omap_i2c.2: bus 2 rev4.0 at 100 kHz
Advanced Linux Sound Architecture Driver Version 1.0.23.
Switching to clocksource gp timer
musb-hdrc: version 6.0, host, debug=0
musb-hdrc musb-hdrc.0: dma type: dma-cppi41
registerd cppi-dma Intr @ IRQ 17
Cppi41 Init Done
musb-hdrc: kernel must blacklist external hubs
musb-hdrc musb-hdrc.0: MUSB HDRC host driver
musb-hdrc musb-hdrc.0: new USB bus registered, assigned bus number 1
usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
usb usb1: Product: MUSB HDRC host driver
usb usb1: Manufacturer: Linux 2.6.37 musb-hcd
usb usb1: SerialNumber: musb-hdrc.0
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 1 port detected
musb-hdrc musb-hdrc.0: USB Host mode controller at d080c000 using DMA, IRQ 18
musb-hdrc musb-hdrc.1: dma type: dma-cppi41
musb-hdrc: kernel must blacklist external hubs
musb-hdrc musb-hdrc.1: MUSB HDRC host driver
musb-hdrc musb-hdrc.1: new USB bus registered, assigned bus number 2
usb usb2: New USB device found, idVendor=1d6b, idProduct=0002
usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
usb usb2: Product: MUSB HDRC host driver
usb usb2: Manufacturer: Linux 2.6.37 musb-hcd
usb usb2: SerialNumber: musb-hdrc.1
hub 2-0:1.0: USB hub found
hub 2-0:1.0: 1 port detected
musb-hdrc musb-hdrc.1: USB Host mode controller at d081e800 using DMA, IRQ 19
NET: Registered protocol family 2
IP route cache hash table entries: 2048 (order: 1, 8192 bytes)
TCP established hash table entries: 8192 (order: 4, 65536 bytes)
TCP bind hash table entries: 8192 (order: 3, 32768 bytes)
TCP: Hash tables configured (established 8192 bind 8192)
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.
NetWinder Floating Point Emulator V0.97 (double precision)
sr1_fck HVT rate = 125000000
sr2_fck SVT rate = 125000000
SR NTarget value for HVT 0xaae2fe
SR NTarget value for SVT 0xaaadc5
SmartReflex Driver initialized
omap-iommu omap-iommu.0: ducati registered
omap-iommu omap-iommu.1: sys registered
JFFS2 version 2.2. (NAND) ?? 2001-2006 Red Hat, Inc.
msgmni has been set to 397
io scheduler noop registered
io scheduler deadline registered
io scheduler cfq registered (default)
Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
omap_uart.0: ttyO0 at MMIO 0x48020000 (irq = 72) is a OMAP UART0
omap_uart.1: ttyO1 at MMIO 0x48022000 (irq = 73) is a OMAP UART1
omap_uart.2: ttyO2 at MMIO 0x48024000 (irq = 74) is a OMAP UART2
console [ttyO2] enabled, bootconsole disabled
console [ttyO2] enabled, bootconsole disabled
brd: module loaded
loop: module loaded
ahci ahci.0: forcing PORTS_IMPL to 0x3
ahci ahci.0: AHCI 0001.0100 32 slots 2 ports 3 Gbps 0x3 impl platform mode
ahci ahci.0: flags: ncq sntf pm led clo only pmp pio slum part ccc
scsi0 : ahci_platform
scsi1 : ahci_platform
ata1: SATA max UDMA/133 mmio [mem 0x4a140000-0x4a150fff] port 0x100 irq 16
ata2: SATA max UDMA/133 mmio [mem 0x4a140000-0x4a150fff] port 0x180 irq 16
m25p80 spi1.0: found m25p05-nonjedec, expected w25x32
m25p80 spi1.0: m25p05-nonjedec (64 Kbytes)
Creating 4 MTD partitions on "spi_flash":
0x000000000000-0x000000040000 : "U-Boot"
mtd: partition "U-Boot" extends beyond the end of device "spi_flash" -- size truncated to 0x10000
0x000000010000-0x000000012000 : "U-Boot Env"
mtd: partition "U-Boot Env" is out of reach -- disabled
0x000000000000-0x000000280000 : "Kernel"
mtd: partition "Kernel" extends beyond the end of device "spi_flash" -- size truncated to 0x10000
0x000000010000-0x000000010000 : "File System"
mtd: partition "File System" is out of reach -- disabled
omap2-nand driver initializing
NAND device: Manufacturer ID: 0x2c, Chip ID: 0xca (Micron )
Creating 5 MTD partitions on "omap2-nand.0":
0x000000000000-0x000000260000 : "U-Boot"
0x000000260000-0x000000280000 : "U-Boot Env"
0x000000280000-0x0000006c0000 : "Kernel"
0x0000006c0000-0x00000cee0000 : "File System"
0x00000cee0000-0x000010000000 : "Reserved"
davinci_mdio davinci_mdio.0: davinci mdio revision 1.6
davinci_mdio davinci_mdio.0: detected phy mask fffffff9
davinci_mdio.0: probed
davinci_mdio davinci_mdio.0: phy[1]: device 0:01, driver unknown
davinci_mdio davinci_mdio.0: phy[2]: device 0:02, driver unknown
usbcore: registered new interface driver cdc_ether
usbcore: registered new interface driver dm9601
Initializing USB Mass Storage driver...
usbcore: registered new interface driver usb-storage
USB Mass Storage support registered.
mice: PS/2 mouse device common for all mice
i2c /dev entries driver
Linux video capture interface: v2.00
usbcore: registered new interface driver uvcvideo
USB Video Class driver (v1.0.0)
OMAP Watchdog Timer Rev 0x00: initial timeout 60 sec
PSTATE 1ff0000
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
usbcore: registered new interface driver snd-usb-audio
1-0018 supply IOVDD not found, using dummy regulator
1-0018 supply DVDD not found, using dummy regulator
1-0018 supply AVDD not found, using dummy regulator
1-0018 supply DRVDD not found, using dummy regulator
asoc: tlv320aic3x-hifi <-> davinci-mcasp.2 mapping ok
ALSA device list:
#0: TI81XX EVM
TCP cubic registered
NET: Registered protocol family 17
VFP support v0.3: implementor 41 architecture 3 part 30 variant c rev 3
omap_voltage_late_init: Voltage driver support not added
ata2: SATA link down (SStatus 0 SControl 300)
ata1: SATA link down (SStatus 0 SControl 300)
mmc0: new high speed SDHC card at address e624
mmcblk0: mmc0:e624 SD08G 7.40 GiB
mmcblk0: p1 p2 p3
davinci_mdio davinci_mdio.0: resetting idled controller
net eth0: attached PHY driver [Generic PHY] (mii_bus:phy_addr=0:01, id=282f014)
IP-Config: Complete:
device=eth0, addr=192.168.0.12, mask=255.255.255.0, gw=192.168.0.1,
host=192.168.0.12, domain=, nis-domain=(none),
bootserver=192.168.0.11, rootserver=192.168.0.11, rootpath=
VFS: Unable to mount root fs via NFS, trying floppy.
VFS: Cannot open root device "nfs" or unknown-block(2,0)
Please append a correct "root=" boot option; here are the available partitions:
1f00 64 mtdblock0 (driver?)
1f02 64 mtdblock2 (driver?)
1f04 2432 mtdblock4 (driver?)
1f05 128 mtdblock5 (driver?)
1f06 4352 mtdblock6 (driver?)
1f07 204928 mtdblock7 (driver?)
1f08 50304 mtdblock8 (driver?)
b300 7761920 mmcblk0 driver: mmcblk
b301 40131 mmcblk0p1 00000000-0000-0000-0000-000000000mmcblk0p1
b302 883575 mmcblk0p2 00000000-0000-0000-0000-000000000mmcblk0p2
b303 6835657 mmcblk0p3 00000000-0000-0000-0000-000000000mmcblk0p3
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(2,0)
Backtrace:
[<c0043b44>] (dump_backtrace+0x0/0x110) from [<c0353b74>] (dump_stack+0x18/0x1c)
r7:cc812000 r6:00000000 r5:c002b71c r4:c04b98d0
[<c0353b5c>] (dump_stack+0x0/0x1c) from [<c0353bd8>] (panic+0x60/0x17c)
[<c0353b78>] (panic+0x0/0x17c) from [<c0009254>] (mount_block_root+0x1e0/0x220)
r3:00000000 r2:00000000 r1:cc82bf58 r0:c040632c
[<c0009074>] (mount_block_root+0x0/0x220) from [<c0009340>] (mount_root+0xac/0xcc)
[<c0009294>] (mount_root+0x0/0xcc) from [<c00094d0>] (prepare_namespace+0x170/0x1d4)
r4:c04b9264
[<c0009360>] (prepare_namespace+0x0/0x1d4) from [<c0008784>] (kernel_init+0x114/0x154)
r5:c0008670 r4:c04b9200
[<c0008670>] (kernel_init+0x0/0x154) from [<c0063ae0>] (do_exit+0x0/0x5e4)
r5:c0008670 r4:00000000
