linux-2.6.30.4移植至2440開發(fā)板
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一、下載linux-2.6.30.4源碼，并解壓
ftp://ftp.kernel.org/pub/linux/kernel/v2.6/linux-2.6.30.4.tar.gz
本文引用地址：http://butianyuan.cn/article/201611/319974.htmtar zxvf linux-2.6.30.4.tar.gz
二、在系統(tǒng)中添加對ARM的支持
$vim Makefile
193#ARCH ?= $(SUBARCH)
194#CROSS_COMPILE ?=
195 ARCH=arm
196 CROSS_COMPILE=arm-linux-
三、修改系統(tǒng)時鐘
$vim arch/arm/mach-s3c2440/mach-smdk2440.c
系統(tǒng)的外部時鐘為12MHz
160static void __init smdk2440_map_io(void)
161{
162s3c24xx_init_io(smdk2440_iodesc,ARRAY_SIZE(smdk2440_iodesc));
163//s3c24xx_init_clocks(16934400);
164//edit by
165 s3c24xx_init_clocks(12000000);
166s3c24xx_init_uarts(smdk2440_uartcfgs,ARRAY_SIZE(smdk2440_uartcfgs));
167}
說明：如果系統(tǒng)時鐘不匹配，則出現(xiàn)亂碼。
四、制作或者獲取內(nèi)核配置單.config
$make menuconfig
說明：一個比較好的做法是先調(diào)用自帶的配置清單，該配置清單在arch/arm/configs目錄，文件名為：s3c2410_defconfig，該配置文件幾乎S3C24XX系列CPU的配置項，可以在此基礎上修改配置項。x86的配置項在arch/x86/configs目錄下，文件名為：i386_defconfig(32為cpu)。
cp arch/arm/configs/s3c2410_defconfig .config
五、修改機器碼
【linux內(nèi)核源碼中查看機器碼相關文件：】
$vim arch/arm/mach-s3c2440/mach-smdk2440.c
178 MACHINE_START(S3C2440 , "SMDK2440")
179/* Maintainer: Ben Dooks
180.phys_io = S3C2410_PA_UART,
181.io_pg_offst = (((u32)S3C24XX_VA_UART)>> 18) & 0xfffc,
182.boot_params = S3C2410_SDRAM_PA+ 0x100,
183
184 .init_irq = s3c24xx_init_irq,
185.map_io = smdk2440_map_io,
186.init_machine = smdk2440_machine_init,
187.timer = &s3c24xx_timer,
188MACHINE_END
修改機器碼，使之與bootloader的機器碼相同，這里使用的是u-boot，機器碼為168
$vim arch/arm/tools/mach-types
379 s3c2440 ARCH_S3C2440 S3C2440168
$vim arch/arm/tools/Makefile
7 include/asm-arm/mach-types.h :$(src)/gen-mach-types $(src)/mach-types
8@echo Generating $@
9@mkdir -p $(dir $@)
10$(Q)$(AWK) -f $^ > $@ || { rm -f $@; /bin/false; }
$vim include/asm/mach-types.h
375 #define MACH_TYPE_S3C2440168 //這個沒有找見
【U-boot中的相關配置文件】
$vim include/asm-arm/mach-types.h
377 #define MACH_TYPE_S3C2440 168
總結：首先從linux內(nèi)核源碼中找出機器類型(如S3C2440 )，其次，根據(jù)u-boot中給出的對應機器類型的機器碼(如377 #define MACH_TYPE_S3C2440 168 )修改內(nèi)核機器碼。流程如下：
內(nèi)核：
$vimarch/arm/mach-s3c2440/mach-smdk2440.c
U-boot:
$viminclude/asm-arm/mach-types.h
內(nèi)核：
$vimarch/arm/tools/mach-types
說明：如果機器碼錯誤，則系統(tǒng)提示選取平臺，死機。
六、編譯鏡像
$make zImage
七、板子燒寫
使用DNW工具將內(nèi)核鏡像燒寫至開發(fā)板中
八、遇到的問題
問題：
Kernel panic - not syncing: Attempted to kill init!
解決辦法：
$make menuconfig
選擇以下兩項：
Kernel Features --->
[*] Use the ARM EABI to compile the kernel
[*] Allow old ABI binaries to run with this kernel (EXPERIMENTAL)
九、NandFlash驅(qū)動移植
linux里面已經(jīng)包含NandFlash驅(qū)動，只需對源碼進行修改即可。
1、$vim arch/arm/plat-s3c24xx/common-smdk.c
107 /* NAND parititon from 2.4.18-swl5*/
108
109 static struct mtd_partitionsmdk_default_nand_part[] = {
110#if defined(CONFIG_64MB_NAND )
111 [0] = {
112.name = "Board_uboot",
113.size = 0x00040000,
114.offset = 0x00000000,
115},
116[1] = {
117.name = "Board_kernel",
118.size = 0x00200000,
119.offset= 0x00200000,
120},
121[2] = {
122.name = "Board_yaffs2",
123.size = 0x03BF8000,
124.offset = 0x00400000,
125}
126#elif defined(CONFIG_128MB_NAND)
127 [0]={
128.name ="Board_uboot",
129.offset =0x00000000,
130.size =0x00040000,
131},
132[1]={
133.name ="Board_kernel",
134.offset =0x00200000,
135.size =0x00200000,
136},
137[2]={
138.name ="Board_yaffs2"
139.offset =0x00400000,
140.size =0x07BA0000,
141}
142 #elif defined(CONFIG_more_than_256MB_NAND)
143 [0]={
144.name ="Board_uboot",
145.offset =0x00000000,
146.size =0x00040000,
147},
148[1]={
149.name ="Board_kernel",
150.offset =0x00200000,
151.size =0x00200000,
152},
153[2]={
154.name ="Board_yaffs2",
155.offset =0x00400000,
156.size =0x0FB80000,
157}
158#endif
159};
2、$vimdrivers/mtd/nand/Kconfig
166 choice
167prompt "Nand Flash Capacity select"
168depends on MTD
169help
170Board Nand Flash Capacity select
171
172 config 64MB_NAND
173 boolean "64MB Nand for Board"
174depends on MTD
175help
176Set 64MB Nand parts
177
178 config 128MB_NAND
179boolean "128MB Nand for Board"
180depends on MTD
181help
182Set 128MB Nand parts
183
184 config more_than_256MB_NAND
185boolean "256MB~1GB Nand for Board"
186depends on MTD
187help
188Set 256MB~1GB Nand parts
189
190 endchoice
注：如果在make menuconfig中選中64MB_NAND，則在.config表現(xiàn)形式如下：
CONFIG _64MB_NAND=y
這實際是給C源文件提供預編譯變量，如#if defined(CONFIG_64MB_NAND).......
這個過程就是實現(xiàn)了內(nèi)核的定制，比如新增Nand驅(qū)動、或者去除wireless驅(qū)動。。。
十、移植yaffs2文件系統(tǒng)
1、獲取yaffs2源碼
http://www.aleph1.co.uk/cgi-bin/viewcvs.cgi/
www.aleph1.co.uk/home/aleph1/git/yaffs2
2、在內(nèi)核中添加對yaffs2的支持
在剛下載的yaffs2源碼中，執(zhí)行：
./patch-ker.sh c ../linux-2.6.30.4（兩個文件夾放一起）
此時在內(nèi)核fs目錄下，新增“yaffs2”目錄，同時fs/目錄下面的Makefile文件和Kconfig文件也添加了yaffs2的配置和編譯條件。
3、在配置單中添加對yaffs2的支持
$make menuconfig
File systems --->
[*]Miscellaneous filesystems --->
<*> YAFFS2 file system support
注意：假如在內(nèi)核中沒有添加對yaffs2的支持，則出現(xiàn)找不到或者掛載文件系統(tǒng)是失敗的提示：
Listof all partitions:
01004096 ram0 (driver?)
01014096 ram1 (driver?)
01024096 ram2 (driver?)
01034096 ram3 (driver?)
01044096 ram4 (driver?)
01054096 ram5 (driver?)
01064096 ram6 (driver?)
01074096 ram7 (driver?)
01084096 ram8 (driver?)
01094096 ram9 (driver?)
010a 4096 ram10 (driver?)
010b4096 ram11 (driver?)
010c 4096 ram12 (driver?)
010d4096 ram13 (driver?)
010e4096 ram14 (driver?)
010f 4096 ram15 (driver?)
1f00 256 mtdblock0 (driver?)
1f01 2048 mtdblock1 (driver?)
1f02 63168 mtdblock2 (driver?)
Nofilesystem could mount root, tried: ext3 ext2 cramfs msdos vfat romfs
Kernel panic - not syncing: VFS: Unable tomount root fs on unknown-block(31,2)
4、yaffs2移植完成，重新編譯內(nèi)核
十一、在內(nèi)核中添加tmpfs支持
如果不添加tmpfs支持，那么將會出現(xiàn)那/tmp掛載失敗的提示。關于tmpfs的作用待研究。
mount: mounting tmpfs on /tmp failed: Invalidargume
文件系統(tǒng)配置：
[root@ /]#cat /etc/fstab
proc /proc proc defaults 0 0
tmpfs /tmp tmpfs defaults 0 0
sysfs /sys sysfs defaults 0 0
tmpfs /dev tmpfs defaults 0 0
var /dev tmpfs defaults 0 0
File systems --->
Pseudo filesystems --->
[*] Virtual memory file system support(former shm fs)
[*]Tmpfs POSIX Access Control Lists
十二遇到的問題及解決方案
drivers/rtc/hctosys.c:unable to open rtc device (rtc0)
1. 內(nèi)核配置選項
--- Real TimeClock
[*] Set system time from RTC on startup andresume
(rtc0) RTC used to set the systemtime
[ ] RTC debugsupport
*** RTC interfaces***
[*] /sys/class/rtc/rtcN(sysfs)
[*] /dev/rtcN (characterdevices)
[ ] RTC UIE emulation on devinterface
*** on-CPU RTC drivers***
<*> Samsung S3Cseries SoC RTC
2. linux kernel 中 已經(jīng)支持S3C2410的RTC，但是并沒有添加到平臺設備初始化數(shù)組中，所以系統(tǒng)啟動時并不會初始化這一部分，需要修改文件mach-smdk.c
static struct platform_device*smdk2410_devices[] __initdata = {
&s3c_device_ohci,
&s3c_device_lcd,
&s3c_device_wdt,
&s3c_device_i2c0,
&s3c_device_iis,
&s3c_device_rtc, //新增代碼
};
3. 創(chuàng)建設備節(jié)點，在文件系統(tǒng)/dev目錄下執(zhí)行:
sudo mknod rtc c 10 135
4. 重新編譯內(nèi)核，查看啟動信息
s3c2410-rtcs3c2410-rtc: rtc disabled,re-enabling
s3c2410-rtcs3c2410-rtc: rtc core:registered s3c asrtc0
這里說明rtc驅(qū)動起來可以正常工作了
uncorrectable error :<3>end_request: I/O error, dev mtdblock2, sector 2
EXT3-fs: unable to readsuperblock
uncorrectable error :<3>end_request: I/O error, dev mtdblock2, sector 2
EXT2-fs: unable to readsuperblock
uncorrectable error :<3>end_request: I/O error, dev mtdblock2, sector 0
Buffer I/O error ondevice mtdblock2, logical block 0
uncorrectable error :<3>end_request: I/O error, dev mtdblock2, sector 0
Buffer I/O error ondevice mtdblock2, logical block 0
uncorrectable error :<3>end_request: I/O error, dev mtdblock2, sector 8
Buffer I/O error ondevice mtdblock2, logical block 1
uncorrectable error :<3>end_request: I/O error, dev mtdblock2, sector 8
Buffer I/O error ondevice mtdblock2, logical block 1
uncorrectable error :<3>end_request: I/O error, dev mtdblock2, sector 16
Buffer I/O error ondevice mtdblock2, logical block 2
uncorrectable error :<3>end_request: I/O error, dev mtdblock2, sector 16
Buffer I/O error ondevice mtdblock2, logical block 2
uncorrectable error :<3>end_request: I/O error, dev mtdblock2, sector 24
Buffer I/O error ondevice mtdblock2, logical block 3
uncorrectable error :<3>end_request: I/O error, dev mtdblock2, sector 24
Buffer I/O error ondevice mtdblock2, logical block 3
uncorrectable error :<3>end_request: I/O error, dev mtdblock2, sector 0
FAT: unable to read bootsector
VFS: Cannot open rootdevice "mtdblock2" or unknown-block(31,2)
Please append a correct"root=" boot option; here are the available partitions:
1f00 256 mtdblock0 (driver?)
1f01 2048 mtdblock1 (driver?)
1f02 257536 mtdblock2 (driver?)
Kernel panic - notsyncing: VFS: Unable to mount root fs on unknown-block(31,2)
MTD分區(qū)與bootloader不匹配
#elif defined(CONFIG_more_than_256MB_NAND)
[0]= {
.name = "Board_uboot",
.offset = 0x00000000,
.size = 0x00080000,
},
[1]= {
.name = "Board_kernel",
.offset= 0x00240000,
.size = 0x00200000,
},
[2]= {
.name = "Board_yaffs2",
.offset= 0x00440000,
.size = 0x0FB40000,
}
**************************************************************************************************************************************************************
[0]和[1]分區(qū)不連貫的表面原因 中間的部分存放uboot的參數(shù)以及開機畫面???環(huán)境變量
uboot分區(qū)信息：
0x0 到0x40000為uboot的分區(qū)，256K，
0x40000到0x4c000 為parameters分區(qū)，48K，
0x50000到0x70000 為eboot分區(qū)，128K，
0x70000到0x1F0000為logo分區(qū)，1536K，
0x1F0000 到0x3F0000為kernel分區(qū)，2M，
0x3F0000 到0x3FF8000 為root分區(qū)，60.03125M
nand分區(qū)信息：
static struct mtd_partition smdk_default_nand_part[] = {
[0] = {
.name = "TQ2440_uboot",
.size = 0x00040000,
.offset = 0x00000000,
},
[1] = {
.name = "TQ2440_kernel",
.offset = 0x0004C000,
.size = 0x00200000,
},
[2] = {
.name = "TQ2440_yaffs2",
.offset = 0x0024C000,
.size = 0x03DB0000,
}
};
uboot的分區(qū)和文件系統(tǒng)的分區(qū)，沒有聯(lián)系的。唯一的聯(lián)系就是uboot引導啟動的時候，命令要根據(jù)文件系統(tǒng)的分區(qū)信息來引導。比如要從mtdblock2啟動，那么bootcmd中的命令bootm0xXXXXXXX就要和mtdblock2的首地址一樣。。。。
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