linux内核可以用nfs挂载吗,使用NFS挂载根文件系统和Linux内核

雨点打透心脏的1/2处 2023-01-20 08:17 65阅读 0赞

使用NFS挂载根文件系统，在开发阶段有很多的好处，对根文件系统进行修改后不用每次都下载到NandFlash中，可以把制作的根文件系统放到主机中的NFS输出目录中，在正式成为产品以后在烧写到开发板中，这样可以方便很多，也可以把编译生成的内核也放到NFS输出目录中这样也可以引导内核，很是方便，还等什么开始吧！

NFS服务器端的配置已经在上一篇文章中写到过了。U-boot中使用tftp协议也在另一篇文章中。按道理来说NFS命令也是可以是使用的，因为都是基于网卡的，只要网卡驱动移植的没有问题，NFS也就直接可以使用了，不过在我这里可是行不通，在使用NFS传输文件中，一直出现下面的错误类型，提示挂载不上：

U-Boot@mini2440\]\#nfs 0x30000000 10.27.10.48:/home/ubuntu/kernel/fs/u-boot.bin

dm9000 i/o: 0x20000300, id: 0x90000a46

DM9000: running in 16 bit mode

MAC: 08:00:3e:26:0a:5b

operating at 100M full duplex mode

Using dm9000 device

File transfer via NFS from server 10.27.10.48; our IP address is 10.27.10.23

Filename '/home/ubuntu/kernel/fs/u-boot.bin'.

Load address: 0x30000000

Loading: \*\*\* ERROR: Cannot mount //仅仅提示挂载不上可还有下面的错误：

\[U-Boot@mini2440\]\#nfs 0x30000000 10.27.10.48:/home/ubuntu/kernel/fs/u-boot.bin

dm9000 i/o: 0x20000300, id: 0x90000a46

DM9000: running in 16 bit mode

MAC: 08:00:3e:26:0a:5b

operating at 100M full duplex mode

Using dm9000 device

File transfer via NFS from server 10.27.10.48; our IP address is 10.27.10.23

Filename '/home/ubuntu/kernel/fs/u-boot.bin'.

Load address: 0x30000000

Loading: \*\*\* ERROR: Cannot mount

\*\*\* ERROR: Cannot umount //这里还提示了不能卸载在网上查找资料，出现 Cannot umount错误的解决方法是修改u-boot-2009.08/net/nfs.c文件，在大约453行附近的位置：

static intnfs\_umountall\_reply (uchar \*pkt, unsigned len)

struct rpc\_t rpc\_pkt;

debug("%s\\n", \_\_func\_\_);

memcpy ((unsigned char \*)&rpc\_pkt, pkt, len);

//if (ntohl(rpc\_pkt.u.reply.id) != rpc\_id) //原来的这一行修改成下面的一行

if ((ntohl(rpc\_pkt.u.reply.id)+1) != rpc\_id)

return -1;

if (rpc\_pkt.u.reply.rstatus ||

..................

\}可是在我这里修改完以后还是不可以使用，一样出现上面的错误。这是就想到了是不是和tftp时出现的错误是一样的，也是因为超时的原因，虽然这里面没有出现超时的提示，不管怎么样还是先改了再说；还是在/nfs.c文件中修改下面的超时的宏定义：

\#define HASHES\_PER\_LINE 65    /\* Number of "loading" hashes per line    \*/

\#define NFS\_RETRY\_COUNT 30

\#define NFS\_TIMEOUT (30\*2000UL) //把原来的2000UL改成 30\*2000UL，修改完上面的宏定义以后，再使用NFS传输文件，一开始有几次还是不成功，不过后面再使用时大部分情况下都是成功的，不再像上面一次也没有成功过：

\[U-Boot@mini2440\]\#nfs 0x30000000 10.27.10.48:/home/zfz/kernel/fs/u-boot.bin

dm9000 i/o: 0x20000300, id: 0x90000a46

DM9000: running in 16 bit mode

MAC: 08:00:3e:26:0a:5b

operating at 100M full duplex mode

Using dm9000 device

File transfer via NFS from server 10.27.10.48; our IP address is 10.27.10.23

Filename '/home/zfz/kernel/fs/u-boot.bin'.

Load address: 0x30000000

Loading: \#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#

done

Bytes transferred = 155016 (25d88 hex)既然NFS可以使用了，那就可以用NFS挂载根文件系统了。根文件系统的制作在另一篇文章中也已经写了，这里就还是使用上次的根文件系统，只是不再用工具制作成Yaffs2的镜像了，直接使用Busybox,制作成功的noot\_nfs目录下的各个文件就可以了，如果要下载到NandFlash中，再使用Yaffs2格式的镜像文件。

可以先用NFS把Linux内核下载到内存中，然后设置传递给内核的参数，在u-boot-2009.08/include/configs/mini2440.h文件中，修改原来使用nand read 方式，修改成使用NFS方式的；

//\#define CONFIG\_BOOTCOMMAND    "nand read 0x32000000 0x60000 0x560000;bootm 0x32000000"//把上面的注释掉，修改成下面的方式

\#define CONFIG\_BOOTCOMMAND "nfs 0x30000800 10.27.10.48:/home/zfz/kernel/fs/uImage.img;bootm"   这样，在用U-boot引导时就可以把Linux的内核首先复制到内存中了，这样也不用把Linux 内核下载到开发板中了。然后在修改传递给内核的参数，修改为下面的：

//\#define CONFIG\_BOOTARGS    "noinitrd root=/dev/mtdblock3 init=/linuxrc console=ttySAC0,115200 mem=64M"//把上面的修改成下面的这句

\#define CONFIG\_BOOTARGS "noinitrd root=/dev/nfs rw nfsroot=10.27.10.48:/home/ubuntu/kernel/fs/root\_nfs ip=10.27.10.23:10.27.10.48::255.255.255.0 console=ttySAC0,115200 init=/linuxrc mem=64M"

可不要忘记把你的Linux内核的镜像文件和你制作的根文件系统的放到NFS的输出目录中；在配置内核中要选中支持NFS文件系统：支持网卡驱动，还用NetWorking Support如下图所示：

Network File System的支持

这样内核配置完以后启动U-boot出现下面的错误：

...........

No device for DAI UDA134X

No device for DAI s3c24xx-i2s

ALSA device list:

No soundcards found.

TCP cubic registered

NET: Registered protocol family 17

drivers/rtc/hctosys.c: unable to open rtc device (rtc0)

IP-Config: No network devices available. //这里没有找到网卡的驱动

Looking up port of RPC 100003/2 on 10.27.10.48

rpcbind: server 10.27.10.48 not responding, timed out

Root-NFS: Unable to get nfsd port number from server, using default

Looking up port of RPC 100005/1 on 10.27.10.48

rpcbind: server 10.27.10.48 not responding, timed out

Root-NFS: Unable to get mountd port number from server, using default

Root-NFS: Server returned error -5 while mounting /home/zfz/kernel/fs/root\_nfs

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 256 mtdblock0 (driver?)

1f01 128 mtdblock1 (driver?)

1f02 5120 mtdblock2 (driver?)

1f03 125568 mtdblock3 (driver?)

1f04 131072 mtdblock4 (driver?)

Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(2,0)

\[\] (unwind\_backtrace+0x0/0xdc) from \[\] (panic+0x40/0x120)

\[\] (panic+0x40/0x120) from \[\] (mount\_block\_root+0x1d0/0x210)

\[\] (mount\_block\_root+0x1d0/0x210) from \[\] (prepare\_namespac)

\[\] (prepare\_namespace+0x164/0x1bc) from \[\] (kernel\_init+0xd)

\[\] (kernel\_init+0xd8/0x10c) from \[\] (kernel\_thread\_exit+0x0)在使用NFS挂载根文件系统时，需要在系统启动到后面时，使用NFS传送根文件系统，这是需要了DM9000网卡的驱动，虽然我们在u-boot中移植了DM9000网卡的驱动，不过现在已经进入到了Linux中，在配置Linux内核中虽然我们也选择了支持DM9000网卡的驱动，不过还是需要在Linux内核中改动才能适应开发板上的网卡，下面就要在Linux中移植DM9000网卡的驱动程序。

Linux2.6.32已经对DM9000网卡有着比较完善的支持了，在：linux-2.6.32.2/

drivers/net/dm9000.c文件中，只需要在目标平台初始化代码中，填写完相应的结构表就可以了，在另一篇文章中，Linux2.6.32.2移植到MINI2440中，我们在linux-2.6.32.2/arch/arm/mach-s3c2440目录下建立了我们自己的文件mach-mini2440.c,主要在这个文件下添加修改；首先添加驱动所需要的头文件：

\#include 然后定义 DM9000网卡的物理基地址

\#define MACH\_MINI2440\_DM9K\_BASE (S3C2410\_CS4 + 0x300)再填写该平台设备的资源设置，以便和 DM9000 网卡驱动接口配合起来；

static struct resource mini2440\_dm9k\_resource\[\] = \{

\[0\] = \{

.start = MACH\_MINI2440\_DM9K\_BASE,

.end = MACH\_MINI2440\_DM9K\_BASE + 3,

.flags = IORESOURCE\_MEM

\},

\[1\] = \{

.start = MACH\_MINI2440\_DM9K\_BASE + 4,

.end = MACH\_MINI2440\_DM9K\_BASE + 7,

.flags = IORESOURCE\_MEM

\},

\[2\] = \{

.start = IRQ\_EINT7,

.end = IRQ\_EINT7,

.flags = IORESOURCE\_IRQ | IORESOURCE\_IRQ\_HIGHEDGE,

\};

/\*

\* \* \* The DM9000 has no eeprom, and it's MAC address is set by

\* \* \* the bootloader before starting the kernel.

\* \* \*/

static struct dm9000\_plat\_data mini2440\_dm9k\_pdata = \{

.flags = (DM9000\_PLATF\_16BITONLY | DM9000\_PLATF\_NO\_EEPROM),

\};

static struct platform\_device mini2440\_device\_eth = \{

.name = "dm9000",

.id = -1,

.num\_resources = ARRAY\_SIZE(mini2440\_dm9k\_resource),

.resource = mini2440\_dm9k\_resource,

.dev = \{

.platform\_data = &mini2440\_dm9k\_pdata,

\},

\};然后在 mini2440 设备集中添加上面做好的网卡平台设备，如下红色部分

static struct platform\_device \*mini2440\_devices\[\] \_\_initdata = \{

&s3c\_device\_usb,

&s3c\_device\_lcd,

&s3c\_device\_wdt,

&s3c\_device\_i2c0,

&s3c\_device\_iis,

&mini2440\_device\_eth,

&s3c\_device\_nand,

\};因为 Linux-2.6.32.2 中虽然有 DM9000 网卡驱动，但并不是完全的适合mini2440，所以还是需要修改，修改DM9000 所用的位宽寄存器，在linux-2.6.32.2/ drivers/net/dm9000.c，添加下面的头文件

\#if defined (CONFIG\_ARCH\_S3C2410)

\#include

\#endif在dm9000设备的初始化函数中添加如下红色部分，这里是配置 DM9000 所用片选总线的时序，大约在1557行附近的位置，

static int \_\_init

dm9000\_init(void)

\#if defined(CONFIG\_ARCH\_S3C2410) unsigned int oldval\_bwscon = \*(volatile unsigned int\*)S3C2410\_BWSCON; unsigned int oldval\_bankcon4 = \*(volatile unsigned int\*)S3C2410\_BANKCON4; \*((volatile unsigned int \*)S3C2410\_BWSCON) = (oldval\_bwscon & ~(3<<16)) | S3C2410\_BWSCON\_DW4\_16 | S3C2410\_BWSCON\_WS4 | S3C2410\_BWSCON\_ST4; oldval\_bankcon4 = 0x1f7c; \#endif

printk(KERN\_INFO "%s Ethernet Driver, V%s\\n", CARDNAME, DRV\_VERSION);

return platform\_driver\_register(&dm9000\_driver);

在配置Linux内核中，加入对DM9000网卡的支持如下图；

这样DM9000网卡的驱动就基本已经移植完成了，这样就可以使用NFS挂载根文件系统了，启动的信息如下：

U-Boot 2009.08 ( 4??月 30 2010 - 20:01:00)

DRAM: 64 MB

Flash: 2 MB

NAND Device: Manufacturer ID: 0xec, Chip ID: 0xf1 (Samsung NAND 128MiB 3,3V 8-b)

NAND: 128 MiB

\*\*\* Warning - bad CRC or NAND, using default environment

In: serial

Out: serial

Err: serial

Net: dm9000

Hit any key to stop autoboot: 0

dm9000 i/o: 0x20000300, id: 0x90000a46

DM9000: running in 16 bit mode

MAC: 08:00:3e:26:0a:5b

operating at 100M full duplex mode

Using dm9000 device

File transfer via NFS from server 10.27.10.48; our IP address is 10.27.10.23

Filename '/home/zfz/kernel/fs/uImage.img'.

Load address: 0x32000000

Loading: \#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#

done

Bytes transferred = 2104236 (201bac hex)

\#\# Booting kernel from Legacy Image at 32000000 ...

Image Name: linux-2.6.32.2

Created: 2010-04-30 15:40:47 UTC

Image Type: ARM Linux Kernel Image (uncompressed)

Data Size: 2104172 Bytes = 2 MB

Load Address: 31000000

Entry Point: 31000000

Verifying Checksum ... OK

Loading Kernel Image ... OK

Starting kernel ...

Uncompressing Linux.............................................................

Linux version 2.6.32.2 (zfz@zfz) (gcc version 4.3.2 (Sourcery G++ Lite 2008q3-70

CPU: ARM920T \[41129200\] revision 0 (ARMv4T), cr=c0007177

CPU: VIVT data cache, VIVT instruction cache

Machine: FriendlyARM MINI2440 development board

Memory policy: ECC disabled, Data cache writeback

CPU S3C2440A (id 0x32440001)

S3C244X: core 405.000 MHz, memory 101.250 MHz, peripheral 50.625 MHz

CLOCK: Slow mode (1.500 MHz), fast, MPLL on, UPLL on

Built 1 zonelists in Zone order, mobility grouping on. Total pages: 16256

Kernel command line: noinitrd root=/dev/nfs rw nfsroot=10.27.10.48:/home/zfz/keM

PID hash table entries: 256 (order: -2, 1024 bytes)

Dentry cache hash table entries: 8192 (order: 3, 32768 bytes)

Inode-cache hash table entries: 4096 (order: 2, 16384 bytes)

Memory: 64MB = 64MB total

Memory: 60480KB available (3696K code, 418K data, 132K init, 0K highmem)

SLUB: Genslabs=11, HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1

Hierarchical RCU implementation.

NR\_IRQS:85

irq: clearing subpending status 00000002

Console: colour dummy device 80x30

console \[ttySAC0\] enabled

Calibrating delay loop... 201.93 BogoMIPS (lpj=504832)

Mount-cache hash table entries: 512

CPU: Testing write buffer coherency: ok

NET: Registered protocol family 16

S3C2440: Initialising architecture

S3C2440: IRQ Support

DMA channel 0 at c4808000, irq 33

DMA channel 1 at c4808040, irq 34

DMA channel 2 at c4808080, irq 35

DMA channel 3 at c48080c0, irq 36

S3C244X: Clock Support, DVS off

bio: create slab at 0

usbcore: registered new interface driver usbfs

usbcore: registered new interface driver hub

usbcore: registered new device driver usb

s3c-i2c s3c2440-i2c: slave address 0x10

s3c-i2c s3c2440-i2c: bus frequency set to 98 KHz

s3c-i2c s3c2440-i2c: i2c-0: S3C I2C adapter

NET: Registered protocol family 2

IP route cache hash table entries: 1024 (order: 0, 4096 bytes)

TCP established hash table entries: 2048 (order: 2, 16384 bytes)

TCP bind hash table entries: 2048 (order: 1, 8192 bytes)

TCP: Hash tables configured (established 2048 bind 2048)

TCP reno registered

NET: Registered protocol family 1

RPC: Registered udp transport module.

RPC: Registered tcp transport module.

RPC: Registered tcp NFSv4.1 backchannel transport module.

yaffs Apr 20 2010 11:10:26 Installing.

msgmni has been set to 118

alg: No test for stdrng (krng)

io scheduler noop registered

io scheduler anticipatory registered (default)

io scheduler deadline registered

io scheduler cfq registered

s3c2410-lcd s3c2410-lcd: no platform data for lcd, cannot attach

s3c2410-lcd: probe of s3c2410-lcd failed with error -22

s3c2440-uart.0: s3c2410\_serial0 at MMIO 0x50000000 (irq = 70) is a S3C2440

s3c2440-uart.1: s3c2410\_serial1 at MMIO 0x50004000 (irq = 73) is a S3C2440

s3c2440-uart.2: s3c2410\_serial2 at MMIO 0x50008000 (irq = 76) is a S3C2440

brd: module loaded

s3c24xx-nand s3c2440-nand: Tacls=3, 29ns Twrph0=7 69ns, Twrph1=3 29ns

s3c24xx-nand s3c2440-nand: NAND soft ECC

NAND device: Manufacturer ID: 0xec, Chip ID: 0xf1 (Samsung NAND 128MiB 3,3V 8-b)

Scanning device for bad blocks

Creating 5 MTD partitions on "NAND 128MiB 3,3V 8-bit":

0x000000000000-0x000000040000 : "U-boot"

0x000000040000-0x000000060000 : "param"

ftl\_cs: FTL header not found.

0x000000060000-0x000000560000 : "Kernel"

ftl\_cs: FTL header not found.

0x000000560000-0x000040560000 : "root"

mtd: partition "root" extends beyond the end of device "NAND 128MiB 3,3V 8-bit"0

ftl\_cs: FTL header not found.

0x000000000000-0x000040000000 : "nand"

mtd: partition "nand" extends beyond the end of device "NAND 128MiB 3,3V 8-bit"0

dm9000 Ethernet Driver, V1.31

eth0: dm9000e at c486e300,c4872304 IRQ 51 MAC: 08:00:3e:26:0a:5b (chip)

ohci\_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver

s3c2410-ohci s3c2410-ohci: S3C24XX OHCI

s3c2410-ohci s3c2410-ohci: new USB bus registered, assigned bus number 1

s3c2410-ohci s3c2410-ohci: irq 42, io mem 0x49000000

usb usb1: configuration \#1 chosen from 1 choice

hub 1-0:1.0: USB hub found

hub 1-0:1.0: 2 ports detected

usbcore: registered new interface driver libusual

mice: PS/2 mouse device common for all mice

i2c /dev entries driver

s3c2410-wdt s3c2410-wdt: watchdog inactive, reset disabled, irq enabled

cpuidle: using governor ladder

sdhci: Secure Digital Host Controller Interface driver

sdhci: Copyright(c) Pierre Ossman

usbcore: registered new interface driver hiddev

usbcore: registered new interface driver usbhid

usbhid: v2.6:USB HID core driver

Advanced Linux Sound Architecture Driver Version 1.0.21.

No device for DAI UDA134X

No device for DAI s3c24xx-i2s

ALSA device list:

No soundcards found.

TCP cubic registered

NET: Registered protocol family 17

drivers/rtc/hctosys.c: unable to open rtc device (rtc0)

eth0: link up, 100Mbps, full-duplex, lpa 0x45E1IP-Config: Complete: device=eth0, addr=10.27.10.23, mask=255.255.255.0, gw=10.27.10.1, host=10.27.10.23, domain=, nis-domain=(none), bootserver=10.27.10.48, rootserver=10.27.10.48, rootpath= //这里和上次的不同

Looking up port of RPC 100003/2 on 10.27.10.48

Looking up port of RPC 100005/1 on 10.27.10.48

VFS: Mounted root (nfs filesystem) on device 0:14.

Freeing init memory: 132K

\--------- munt all--------

\-------- Starting mdev ---------

\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*

\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*Frankzfz ARM Embedded \*\*\*\*\*\*\*\*\*\*\*\*\*\*

Kernel version:linux-2.32.2

Author:zfz

Date:2010,4,29

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