利用uboot传递参数进行内核的不同配置

    如果一个硬件有不同的驱动支持，那么每次还得重新编译内核才能重新加载驱动吗？内核提供了一种很方便的机制，可以让我们通过uboot的命令参数来传递，调用不同的内核驱动。

__setup("xxx=", xxx_setup);

/**
* fb_get_options - get kernel boot parameters
* @name:
framebuffer name as it would appear in
*
the boot parameter line
*
(video=<name>:<options>)
* @option: the option will be stored here
*
* NOTE: Needed to maintain backwards compatibility
*/
int fb_get_options(char *name, char **option)
{
char *opt, *options = NULL;
int retval = 0;
int name_len = strlen(name), i;
if (name_len && ofonly && strncmp(name, "offb", 4))
retval = 1;
if (name_len && !retval) {
for (i = 0; i < FB_MAX; i++) {
if (video_options[i] == NULL)
continue;
if (!video_options[i][0])
continue;
opt = video_options[i];
if (!strncmp(name, opt, name_len) &&
opt[name_len] == ':')
options = opt + name_len + 1;
}
}
if (options && !strncmp(options, "off", 3))
retval = 1;
if (option)
*option = options;
return retval;
}
#ifndef MODULE
/**
*	video_setup - process command line options
*	@options: string of options
*
*	Process command line options for frame buffer subsystem.
*
*	NOTE: This function is a __setup and __init function.
*
It only stores the options.
Drivers have to call
*
fb_get_options() as necessary.
*
*	Returns zero.
*
*/
static int __init video_setup(char *options)
{
int i, global = 0;
if (!options || !*options)
global = 1;
if (!global && !strncmp(options, "ofonly", 6)) {
ofonly = 1;
global = 1;
}
if (!global && !strstr(options,"fb:")) {
fb_mode_option = options;
global = 1;
}
if (!global) {
for (i = 0; i < FB_MAX; i++) {
if (video_options[i] == NULL) {
video_options[i] = options;
break;
}
}
}
return 1;
}
__setup("video=", video_setup);

int fb_get_options(char *name, char **option)

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