linux-2.6.14移植到S3C2440

作者：時間：2016-11-22 來源：網(wǎng)絡(luò)

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現(xiàn)在應(yīng)該很少使用2.6.14的內(nèi)核了，但由于項目需要，最近移植了2.6.版本的內(nèi)核到S3C2440上，并移植了CS8900網(wǎng)卡驅(qū)動(網(wǎng)卡驅(qū)動移植參考http://blog.csdn.net/ce123/article/details/8424399)。之所以移植網(wǎng)卡驅(qū)動，是因為yaffs2格式的文件系統(tǒng)一直掛載不成功，啟動后的錯誤信息如下：

Mounted devfs on /dev
Freeing init memory: 92K
Failed to execute /linuxrc. Attempting defaults...
Kernel panic - not syncing: No init found. Try passing init= option to kernel.

這個問題只能先放一下，最后成功掛載nfs。yaffs2格式文件系統(tǒng)的問題以后再深入研究。整理一下最近做過的東西，怕遺忘了。

1.頂層Makefile的修改

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ARCH?=arm
CROSS_COMPILE?=arm-linux-

交叉編譯器的使用請參考http://blog.csdn.net/ce123/article/details/8333421

2.修改時鐘頻率

linux/arch/arm/mach-s3c2410/mach-smdk2440.c

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staticvoid__initsmdk2440_map_io(void)
{
s3c24xx_init_io(smdk2440_iodesc,ARRAY_SIZE(smdk2440_iodesc));
s3c24xx_init_clocks(12000000);//12M
s3c24xx_init_uarts(smdk2440_uartcfgs,ARRAY_SIZE(smdk2440_uartcfgs));
s3c24xx_set_board(&smdk2440_board);
}

3.修改機(jī)器ID

linux/arch/arm/tools/mach-types

s3c2440 ARCH_S3C2440 S3C2440 168

這個值要和uboot中的值對應(yīng)起來，在uboot的arch/arm/tools/mach-types中有如下定義：

#define MACH_TYPE_S3C2440 168

這兩個值一樣即可。

4.設(shè)置Nand Flash分區(qū)

4.1建立Nand Flash分區(qū)表

在linux/arch/arm/mach-s3c2410/devs.c中增加

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#include
#include
#include
/*NANDparititon*/
staticstructmtd_partitionsmdk_default_nand_part[]={
[0]={
.name="Board_uboot",
.offset=0x00000000,
.size=0x00080000,
},
[1]={
.name="Board_kernel",
.offset=0x00240000,
.size=0x00200000,
},
[2]={
.name="Board_yaffs2",
.offset=0x00440000,
.size=0x0FB40000,
}
};

name：代表分區(qū)名字

size：代表flash分區(qū)大小(單位：字節(jié))
offset：代表flash分區(qū)的起始地址(相對于0x0的偏移)
劃分3個區(qū)，分別存放uboot， kernel和文件系統(tǒng)。

4.2.加入Nand Flash分區(qū)

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staticstructs3c2410_nand_setsmdk_nand_sets[]={
[0]={
.name="NAND",
.nr_chips=1,
.nr_partitions=ARRAY_SIZE(smdk_default_nand_part),
.partitions=smdk_default_nand_part,
},
};

nr_partitions：指明partition_info中定義的分區(qū)數(shù)目
partitions：分區(qū)信息表

4.3.建立Nand Flash芯片支持

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staticstructs3c2410_platform_nandsmdk_nand_info={
.tacls=20,
.twrph0=60,
.twrph1=20,
.nr_sets=ARRAY_SIZE(smdk_nand_sets),
.sets=smdk_nand_sets,
};

tacls，twrph0，twrph1的意思見S3C2440的數(shù)據(jù)手冊，這3個值最后會被設(shè)置到NFCONF中。
sets：支持的分區(qū)集
nr_set：分區(qū)集的個數(shù)

4.4.加入Nand Flash芯片支持到Nand Flash驅(qū)動

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structplatform_devices3c_device_nand={
.name="s3c2410-nand",
.id=-1,
.num_resources=ARRAY_SIZE(s3c_nand_resource),
.resource=s3c_nand_resource,
.dev={
.platform_data=&smdk_nand_info
}
};

name：設(shè)備名稱
id：有效設(shè)備編號，如果只有唯一的一個設(shè)備為-1，有多個設(shè)備從0開始計數(shù).
num_resource：有幾個寄存器區(qū)
resource：寄存器區(qū)數(shù)組首地址
dev：支持的Nand Flash設(shè)備

4.5指定啟動時初始化

linux/arch/arm/mach-s3c2410/mach-smdk2440.c

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staticstructplatform_device*smdk2440_devices[]__initdata={
&s3c_device_usb,
&s3c_device_lcd,
&s3c_device_wdt,
&s3c_device_i2c,
&s3c_device_iis,
&s3c_device_nand,//增加
};

5.禁止Flash ECC校驗

修改drivers/mtd/nand/s3c2410.c 文件s3c2410_nand_init_chip()函數(shù)，在該函數(shù)體最后加上一條語句:

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chip->eccmode=NAND_ECC_NONE;

6.支持devfs

在2.6.14中已經(jīng)不支持devfs了，內(nèi)核配置文件中已經(jīng)沒有了相關(guān)的配置選擇，但其代碼還保留了。修改fs/Kconfig文件找到menu "Pseudo filesystems"添加如下語句：

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configDEVFS_FS
bool"/devfilesystemsupport(OBSOLETE)"
dependsonEXPERIMENTAL
help
Thisissupportfordevfs,avirtualfilesystem(like/proc)which
providesthefilesysteminterfacetodevicedrivers,normallyfound
in/dev.Devfsdoesnotdependonmajorandminornumber
allocations.Devicedriversregisterentriesin/devwhichthen
appearautomatically,whichmeansthatthesystemadministratordoes
nothavetocreatecharacterandblockspecialdevicefilesinthe
/devdirectoryusingthemknodcommand(orMAKEDEVscript)anymore.
Thisisworkinprogress.Ifyouwanttousethis,you*must*read
thematerialin,especially
thefileREADMEthere.
Notethatdevfsnolongermanages/dev/pts!IfyouareusingUNIX98
ptys,youwillalsoneedtomountthe/dev/ptsfilesystem(devpts).
Notethatdevfshasbeenobsoletedbyudev,
.
Ithasbeenstrippeddowntoabareminimumandisonlyprovidedfor
legacyinstallationsthatuseitsnamingschemewhichis
unfortunatelydifferentfromthenamesnormalLinuxinstallations
use.
Ifunsure,sayN.
configDEVFS_MOUNT
bool"Automaticallymountatboot"
dependsonDEVFS_FS
help
ThisoptionappearsifyouhaveCONFIG_DEVFS_FSenabled.Setting
thistoYwillmakethekernelautomaticallymountdevfsonto/dev
whenthesystemisbooted,beforetheinitthreadisstarted.
Youcanoverridethiswiththe"devfs=nomount"bootoption.
Ifunsure,sayN.
configDEVFS_DEBUG
bool"Debugdevfs"
dependsonDEVFS_FS
help
IfyousayYhere,thenthe/devfilesystemcodewillgenerate
debuggingmessages.Seethefile
formore
details.
Ifunsure,sayN.
configDEVPTS_FS_XATTR
bool"/dev/ptsExtendedAttributes"
dependsonUNIX98_PTYS
help
Extendedattributesarename:valuepairsassociatedwithinodesby
thekernelorbyusers(seetheattr(5)manualpage,orvisit
fordetails).
Ifunsure,sayN.
configDEVPTS_FS_SECURITY
bool"/dev/ptsSecurityLabels"
dependsonDEVPTS_FS_XATTR
help
Securitylabelssupportalternativeaccesscontrolmodels
implementedbysecuritymoduleslikeSELinux.Thisoption
enablesanextendedattributehandlerforfilesecurity
labelsinthe/dev/ptsfilesystem.
Ifyouarenotusingasecuritymodulethatrequiresusing
extendedattributesforfilesecuritylabels,sayN.
configTMPFS
bool"Virtualmemoryfilesystemsupport(formershmfs)"
help
Tmpfsisafilesystemwhichkeepsallfilesinvirtualmemory.
Everythingintmpfsistemporaryinthesensethatnofileswillbe
createdonyourharddrive.Thefilesliveinmemoryandswap
space.Ifyouunmountatmpfsinstance,everythingstoredthereinis
lost.
Seefordetails.

7.內(nèi)核裁剪

7.1內(nèi)核配置文件

將arch/arm/configs/s3c2410_defconfig .config拷到內(nèi)核目錄樹根下：
cp arch/arm/configs/s3c2410_defconfig .config
make menuconfig 將s3c2410_defconfig 導(dǎo)入，在s3c2410_defconfig基礎(chǔ)上，裁剪內(nèi)核。

7.2內(nèi)核選項

Loadable module support >
[*] Enable loadable module support
[*] Automatic kernel module loading

System Type >
[*] S3C2410 DMA support

Floating point emulation >
[*] NWFPE math emulation

接下來要做的是對內(nèi)核MTD子系統(tǒng)的設(shè)置

Device Drivers >
Memory Technology Devices (MTD) >
[*] MTD partitioning support /*支持MTD分區(qū)，這樣我們在前面設(shè)置的分區(qū)才有意義*/
[*] Command line partition table parsing /*支持從命令行設(shè)置flash分區(qū)信息，靈活*/
RAM/ROM/Flash chip drivers >
<*> Detect flash chips by Common Flash Interface (CFI) probe
<*> Detect nonCFI AMD/JEDECcompatible flash chips
<*> Support for Intel/Sharp flash chips
<*> Support for AMD/Fujitsu flash chips
<*> Support for ROM chips in bus mapping
NAND Flash Device Drivers >
<*> NAND Device Support
<*> NAND Flash support for S3C2410/S3C2440 SoC
Character devices >
[*] Nonstandard serial port support
[*] S3C2410 RTC Driver

接下來做的是針對文件系統(tǒng)的設(shè)置

File systems >
<> Second extended fs support #去除對ext2的支持
Pseudo filesystems >
[*] /proc file system support
[*] Virtual memory file system support (former shm fs)
[*] /dev file system support (OBSOLETE)
[*] Automatically mount at boot (NEW)
這里會看到我們前先修改fs/Kconfig的成果，devfs已經(jīng)被支持上了
Miscellaneous filesystems >
Network File Systems >
<*> NFS file system support