USB和SD/MMC移植筆記發(fā)布時(shí)間：2009-07-29 00:10:02
USB和SD/MMC移植筆記
一、USB移植
在移植好內核和跟文件系統的基礎上，進(jìn)行USB的移植。
S3C2440集成了USB控制器支持USB1.1版本，支持USB主機和USB設備主機符合OHCI1.0版本，Linux2.6.29.1的內核支持USB控制器，只需在內核中配置即可。
在內核目錄下，輸入make menuconfig，進(jìn)入配置菜單，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命令清除編譯內核的垃圾文件，然后用命令make zImage編譯內核。
在移植的根文件系統系統目錄dev下建立如下的設備文件：
mknod sda1 b 8 1
把編譯好的內核和根文件系統映像文件下載到開(kāi)發(fā)板，啟動(dòng)開(kāi)發(fā)板后插入U盤(pán)，終端出現如下信息：
[@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掛載U盤(pán)：
[@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盤(pán)后出現：
[@MrFeng=W]#usb 1-1: USB disconnect, address 2
二、SD/MMC移植
S3C2440集成了一個(gè)MMC/SD/SDIO主機控制器，用于訪(fǎng)問(wèn)外接的SD、MMC、SDIO卡，linux-2.6.29.1包含了MMC/SD驅動(dòng)程序，只需在內核中配置即可。在內核里做如下配置：
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，把編譯的內核下載到開(kāi)發(fā)板后，插入SD卡終端沒(méi)有任何提示。細細一看，友善之臂的SD卡的寫(xiě)保護不是直接接地的，二是接到GPH8引腳的，于是我在內核文件/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);
//開(kāi)啟LCD背光
s3c2410_gpio_cfgpin(S3C2410_GPG4,S3C2410_GPG4_OUTP);
s3c2410_gpio_setpin(S3C2410_GPG4,1);
//關(guān)閉SD卡寫(xiě)保護
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();
}
重新編譯內核，下載到開(kāi)發(fā)板，將SD卡插入到卡座。在終端出現如下信息：
[@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卡出現：
[@MrFeng=W]#mmc0: card 0002 removed
s3c2440-sdi s3c2440-sdi: powered down.
總結：在高版本的Linux內核中，已集成了USB和SD卡驅動(dòng)，所需的只是配置，低版本的內核需要打補丁然后配置。
