On Thu, Aug 28, 2014 at 7:00 PM, jonsmirl@xxxxxxxxx <jonsmirl@xxxxxxxxx> wrote: > On Thu, Aug 28, 2014 at 9:54 PM, Alexandre Courbot <gnurou@xxxxxxxxx> wrote: >> On Thu, Aug 28, 2014 at 6:40 PM, jonsmirl@xxxxxxxxx <jonsmirl@xxxxxxxxx> wrote: >>> On Thu, Aug 28, 2014 at 9:36 PM, Alexandre Courbot <gnurou@xxxxxxxxx> wrote: >>>> On Thu, Aug 28, 2014 at 12:19 PM, jonsmirl@xxxxxxxxx <jonsmirl@xxxxxxxxx> wrote: >>>>> Is there some existing way to do early printk type output to a >>>>> framebuffer that has been set up by the bootloader? early printk is >>>>> before any device drivers are loaded. >>>>> >>>>> If not, what would it take to create a way to do this? Something along >>>>> the lines of build in the fbdev library and give it an address plus >>>>> x/y layout of the buffer. Assume that everything else is set up and >>>>> anything written to the buffer will appear on the display. Then hook >>>>> into where the kernel does early printk on uarts and add in support >>>>> for this buffer. The core fbdev library implements scrolling and >>>>> graphical characters. >>>> >>>> simplefb does something like this (implement a console on top of a >>>> framebuffer set up by the bootloader), but I don't think you can use >>>> it for earlyprintk. It would be a very interesting option though (and >>> >>> simplefb is a device driver so it doesn't process the early output. >>> This would need to be some custom code that gets the framebuffer >>> address and x/y setup very early in the boot process. I'm fairly sure >>> nothing like it current exists. >> >> You're right AFAICT. And although simplefb shares part of of idea it >> also doesn't operate at the required level. Also contrary to what I >> said it also does not implement a console, but just a framebuffer >> device on top of which you need some more logic before you can think >> about displaying strings. > > turn on fbconsole support and it should work. Yeah, but my point was, that I don't think you can use fbconsole that early in the kernel? -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
