Hello,
> I have written a framebuffer device driver for kernel 2.6.21-ts. It
> works fine (tested with embedded qt and other programs which use the
> framebuffer device) but the big problem is that I have to pass the
> screen resolution as a parameter. At
> http://tech.groups.yahoo.com/group/ts-7000/message/6327 I saw that the
> TS driver for kernel version 2.4 can automatically detect the screen
> resolution. How can this be done?
> I would also like to know how can I load my own firmware. Are there any
> sources?
The bit blit functionality is implemented in the firmware. So the bit
blit knows what the resolution of the screen. In order to determine the
screen resolution you can write 0xFF to the first two rows, then bit
blit a rectangle 2 pixels tall by 1 pixel wide of color 0x0. Then start
looking for the offset of the second pixel that is 0x0. This would give
you the width of the screen. We assume the aspect ratio is 4:3, and
calculate the video height. Below is the routine to accomplish this in
the 2.4 framebuffer driver...
/* Use a bit blit to determine the screen resolution, assumes 4:3 aspect
ratio*/
int detect_screen_width()
{
unsigned int i=0, found = 0;
unsigned short *mem = (unsigned short *) fb_info.fb_virt_start;
ts7300_blt(0xFFFF, 0, MAX_WIDTH-1, 2, 1);
ts7300_blt(0, 0, 1-1, 2, 1);
for(i=0;i<(MAX_WIDTH*2);i++) {
if(mem[i] == 0x0) found++;
if(found == 2) break;
}
if(found != 2) {
printk("Framebuffer doesn't support this video core\n");
return 0;
} else { //Assumes a 4:3 aspect ratio
fb_info.xres=i;
fb_info.yres=i*3/4;
printk("Detected %dx%d video core\n",
fb_info.xres, fb_info.yres);
}
return 1;
}
--
Best Regards,
________________________________________________________________
Eddie Dawydiuk, Technologic Systems | voice: (480) 837-5200
16610 East Laser Drive Suite 10 | fax: (480) 837-5300
Fountain Hills, AZ 85268 | web: www.embeddedARM.com
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