立地成佛 回头是岸:SD和USB移植

USB和SD/MMC移植笔记发布时间：2009-07-29 00:10:02
USB和SD/MMC移植笔记
一、USB移植
在移植好内核和跟文件系统的基础上，进行USB的移植。
S3C2440集成了USB控制器支持USB1.1版本，支持USB主机和USB设备主机符合OHCI1.0版本，Linux2.6.29.1的内核支持USB控制器，只需在内核中配置即可。
在内核目录下，输入make menuconfig，进入配置菜单，如下：
Device Drivers-à
SCSI device support-à
<*>SCSI device support
[*]legacy /proc/scsi/ support
<*>SCSI disk support
<*>SCSI CDROM support
[*]HID Devices-à
<*> USB Human Interface Device(full HID)support
[*]   /dev/hiddev raw HID device support
[*]USB support-à
<*> support for Host-side USB
[*] USB device filesystem
[*] USB device class-devices(DEPRECATED)
<*>OHCI HCD support
<*>USB Mass storage support
先用make clean命令清除编译内核的垃圾文件，然后用命令make zImage编译内核。
在移植的根文件系统系统目录dev下建立如下的设备文件：
mknod sda1 b 8 1
把编译好的内核和根文件系统映像文件下载到开发板，启动开发板后插入U盘，终端出现如下信息：
[@MrFeng=W]#ls
bin         etc         linuxrc     proc        sys         var
boot        home        lost+found  root        tmp         www
dev         lib         mnt         sbin        usr
[@MrFeng=W]#usb 1-1: new full speed USB device using s3c2410-ohci and address 2
usb 1-1: New USB device found, idVendor="0204", idProduct="6025"
usb 1-1: New USB device strings: Mfr="0", Product="0", SerialNumber="0"
usb 1-1: configuration #1 chosen from 1 choice
scsi0 : SCSI emulation for USB Mass Storage devices
scsi 0:0:0:0: Direct-Access     USB A    Flash Disk       2.00 PQ: 0 ANSI: 2
sd 0:0:0:0: [sda] 506420 512-byte hardware sectors: (259 MB/247 MiB)
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Assuming drive cache: write through
sd 0:0:0:0: [sda] 506420 512-byte hardware sectors: (259 MB/247 MiB)
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Assuming drive cache: write through
sda: sda1
sd 0:0:0:0: [sda] Attached SCSI removable disk
[@MrFeng=W]#mount -t vfat /dev/sda1 /mnt/usb
FAT: utf8 is not a recommended IO charset for FAT filesystems, filesystem will be case sensitive!
使用命令mount挂载U盘：
[@MrFeng=W]#mount -t vfat /dev/sda1 /mnt/usb
[@MrFeng=W]#ls /mnt/usb
bootloader.tgz         logomaker.tgz          rootfs.img
busybox-1.13.3.tar.gz  mdev.txt               server.c
examples(1).tgz        mini2440_pwm.c         zImage
getaddrinfo.c          mkyaffsimage.tgz
led_driver.c           root_qtopia.img
拔下U盘后出现：
[@MrFeng=W]#usb 1-1: USB disconnect, address 2
二、SD/MMC移植
S3C2440集成了一个MMC/SD/SDIO主机控制器，用于访问外接的SD、MMC、SDIO卡，linux-2.6.29.1包含了MMC/SD驱动程序，只需在内核中配置即可。在内核里做如下配置：
Device Drivers-?
<*>MMC/SD/SDIO card support--->
<*>MMC block device driver
[*]Use bounce buffer for simple hosts
<*>Samsung S3C SD/MMC Card Interface support
配置好后，把编译的内核下载到开发板后，插入SD卡终端没有任何提示。细细一看，友善之臂的SD卡的写保护不是直接接地的，二是接到GPH8引脚的，于是我在内核文件/arch/arm/mash-s3c2440/mach-smdk2440.c中做如下修改：
static void __init smdk2440_machine_init(void)
{
s3c24xx_fb_set_platdata(&smdk2440_fb_info);
s3c_i2c0_set_platdata(NULL);
//开启LCD背光
s3c2410_gpio_cfgpin(S3C2410_GPG4,S3C2410_GPG4_OUTP);
s3c2410_gpio_setpin(S3C2410_GPG4,1);
//关闭SD卡写保护
s3c2410_gpio_cfgpin(S3C2410_GPH8,S3C2410_GPH8_OUTP);
s3c2410_gpio_setpin(S3C2410_GPH8,0);
platform_add_devices(smdk2440_devices, ARRAY_SIZE(smdk2440_devices));
smdk_machine_init();
}
重新编译内核，下载到开发板，将SD卡插入到卡座。在终端出现如下信息：
[@MrFeng=W]#mmc0: card 0002 removed
s3c2440-sdi s3c2440-sdi: powered down.
s3c2440-sdi s3c2440-sdi: running at 0kHz (requested: 0kHz).
s3c2440-sdi s3c2440-sdi: running at 198kHz (requested: 197kHz).
s3c2440-sdi s3c2440-sdi: running at 198kHz (requested: 197kHz).
s3c2440-sdi s3c2440-sdi: running at 198kHz (requested: 197kHz).
s3c2440-sdi s3c2440-sdi: running at 198kHz (requested: 197kHz).
s3c2440-sdi s3c2440-sdi: running at 198kHz (requested: 197kHz).
s3c2440-sdi s3c2440-sdi: running at 198kHz (requested: 197kHz).
s3c2440-sdi s3c2440-sdi: running at 198kHz (requested: 197kHz).
s3c2440-sdi s3c2440-sdi: running at 16875kHz (requested: 25000kHz).
s3c2440-sdi s3c2440-sdi: running at 16875kHz (requested: 25000kHz).
mmc0: new SD card at address 0002
mmcblk0: mmc0:0002 00000 1.90 GiB
mmcblk0:<4>mmcblk0: retrying using single block read
拔下SD卡出现：
[@MrFeng=W]#mmc0: card 0002 removed
s3c2440-sdi s3c2440-sdi: powered down.
总结：在高版本的Linux内核中，已集成了USB和SD卡驱动，所需的只是配置，低版本的内核需要打补丁然后配置。