嵌入式Linux USB WIFI驱动的移植
硬件平台：飞思卡尔MX258开发板
操作系统：Linux2.6.31
WIFI： RT2860 USB WIFI模组
交叉编译环境：gcc version 4.1.2
调试步骤：
第一步：测试USB HOST接口
在menuconfig中将USB HOST设置为内核模式：
重新编译内核后启动开发板，插入U盘并挂载：
mount /dev/sda1 /tmp
ls /tmp
可以看到U盘已经正常挂载，测试USB HOST OK!
第二步：网上下载雷凌最新的USB驱动，
2011_0107_RT3070_RT3370_Linux_STA_v2[1].5.0.1_DPO.tar.bz2
拷备到Linux目录并解压：
tar jxf 2011_0107_RT3070_RT3370_Linux_STA_v2[1].5.0.1_DPO.tar.bz2
由于上面名字很长，可以修改为简短的名字：
mv 2011_0107_RT3070_RT3370_Linux_STA_v2[1].5.0.1_DPO RT3070_Linux_STA
第三步：进入RT3070_Linux_STA目录，看到有一个README_STA_usb文件，里面介绍了如何加载该驱动：
=======================================================================
Build Instructions:
====================
1> $tar -xvzf DPB_RT2870_Linux_STA_x.x.x.x.tgz
go to "./DPB_RT2870_Linux_STA_x.x.x.x" directory.
2> In Makefile
set the "MODE = STA" in Makefile and chose the TARGET to Linux by set "TARGET = LINUX"
define the linux kernel source include file path LINUX_SRC
modify to meet your need.
3> In os/linux/config.mk
define the GCC and LD of the target machine
define the compiler flags CFLAGS
modify to meet your need.
** Build for being controlled by NetworkManager or wpa_supplicant wext functions
Please set 'HAS_WPA_SUPPLICANT=y' and 'HAS_NATIVE_WPA_SUPPLICANT_SUPPORT=y'.
=> #>cd wpa_supplicant-x.x
=> #>./wpa_supplicant -Dwext -ira0 -c wpa_supplicant.conf -d
** Build for being controlled by WpaSupplicant with Ralink Driver
Please set 'HAS_WPA_SUPPLICANT=y' and 'HAS_NATIVE_WPA_SUPPLICANT_SUPPORT=n'.
=> #>cd wpa_supplicant-0.5.7
=> #>./wpa_supplicant -Dralink -ira0 -c wpa_supplicant.conf -d
4> $make
# compile driver source code
# To fix "error: too few arguments to function ˉiwe_stream_add_event"
=> $patch -i os/linux/sta_ioctl.c.patch os/linux/sta_ioctl.c
5> $cp RT2870STA.dat /etc/Wireless/RT2870STA/RT2870STA.dat
6> load driver, go to "os/linux/" directory.
#[kernel 2.4]
# $/sbin/insmod rt2870sta.o
# $/sbin/ifconfig ra0 inet YOUR_IP up
#[kernel 2.6]
# $/sbin/insmod rt2870sta.ko
# $/sbin/ifconfig ra0 inet YOUR_IP up
7> unload driver
$/sbin/ifconfig ra0 down
$/sbin/rmmod rt2870sta
这里go to "./DPB_RT2870_Linux_STA_x.x.x.x" directory.即我们刚解压的RT3070_Linux_STA目录。修改该目录下的makefile文件，以下只给出修改部分：
#PLATFORM = PC
PLATFORM = RALINK_2880
ifeq ($(PLATFORM), RALINK_2880)
LINUX_SRC = /home/lqm/share/G360/kernel_kfb
CROSS_COMPILE = /opt/freescale/usr/local/gcc-4.1.2-glibc-2.5-nptl-3/arm-none-linux-gnueabi/bin/arm-none-linux-gnueabi-
endif
ifeq ($(RT28xx_MODE),APSTA)
cp -f $(RT28xx_DIR)/os/linux/rt$(CHIPSET)apsta.ko /tftpboot
ifeq ($(OSABL),YES)
cp -f $(RT28xx_DIR)/os/linux/rtutil$(CHIPSET)apsta.ko /tftpboot
cp -f $(RT28xx_DIR)/os/linux/rtnet$(CHIPSET)apsta.ko /tftpboot
endif
else
cp -f $(RT28xx_DIR)/os/linux/rt$(CHIPSET)sta.ko /home/lqm/share/NFS/tmp
注意，虽然我们使用的是2860模组，我们这里仍然可以定义PLATFORM为RALINK_2880，只要后面对应的编译环境正确就可以了。LINUX_SRC表示内核的目录，CORSS_COMPILE为交叉编译环境，最末一行为编译完后将生成的KO文件复制到NFS文件系统的tmp目录。
第四步：按照第三步README_STA_usb给出的提示，修改config.mk文件，这里也只给出修改部分：
# Support Wpa_Supplicant
HAS_WPA_SUPPLICANT=y
# Support Native WpaSupplicant for Network Maganger
HAS_NATIVE_WPA_SUPPLICANT_SUPPORT=n
CC := /opt/freescale/usr/local/gcc-4.1.2-glibc-2.5-nptl-3/arm-none-linux-gnueabi/bin/arm-none-linux-gnueabi-gcc
LD := /opt/freescale/usr/local/gcc-4.1.2-glibc-2.5-nptl-3/arm-none-linux-gnueabi/bin/arm-none-linux-gnueabi-ld
ifeq ($(PLATFORM), RALINK_2880)
EXTRA_CFLAGS := -D__KERNEL__ -I$(LINUX_SRC)/include -I$(RT28xx_DIR)/include -Wall -Wstrict-prototypes -Wno-trigraphs -O2 -fno-strict-aliasing -fno-common -Uarm -fno-common -pipe -D__LINUX_ARM_ARCH__=5 -march=armv5te -msoft-float -Uarm -DMODULE -DMODVERSIONS -include $(LINUX_SRC)/include/config/modversions.h $(WFLAGS)
export EXTRA_CFLAGS
endif
注意，这里CC为交叉编译环境，LD为交叉编译的链接。默认EXTRA_CFLAGS为CFLAGS，这里需要修改为EXTRA_CFLAGS，否则编译时会提示如下错误：
scripts/Makefile.build:49: *** CFLAGS was changed in "/home/lqm/share/RT3070_Linux_STA/os/linux/Makefile". Fix it to use EXTRA_CFLAGS。 停止。
LINUX_ARM_ARCH一定要设置为5，-march一定要设置得和CPU匹配，由于这里为MX258，因此设置为armv5te，不可设置为armv5t或armv5，否则出现如下错误：
CC [M] /home/lqm/share/RT3070_Linux_STA/os/linux/../../os/linux/rt_main_dev.o
{standard input}: Assembler messages:
{standard input}:340: Error: selected processor does not support `pld [r5,#0]'
{standard input}:349: Error: selected processor does not support `pld [r5,#0]'
make[2]: *** [/home/lqm/share/RT3070_Linux_STA/os/linux/../../os/linux/rt_main_dev.o] 错误 1
make[1]: *** [_module_/home/lqm/share/RT3070_Linux_STA/os/linux] 错误 2
make[1]: Leaving directory `/home/lqm/share/G360/kernel_kfb'
make: *** [LINUX] 错误 2
[root@lqm RT3070_Linux_STA]#