On Sat, Aug 2, 2014 at 10:06 AM, Luc Verhaegen <[email protected]> wrote: > This patch adds a cfb console driver to u-boot. This patch has 2 functions: > * Make it easier to debug booting issues without UART (but will not solve > all problems). > * Provide a temporary solution to the lack of a full display driver, through > simplefb, while sunxi kms is still worked on. > > This patch: > * claims 8MB of RAM off the top. This will be re-used when a proper display > driver is present, but this is currently lost if not used for a simplefb > fb driver. > * HPD detects whether a HDMI monitor is present. This even works fine on A13 > as well: it correctly fails to detect a monitor. > * sets up 1024x768. It does not do EDID due to the display infrastructure > inside u-boot being very last millenium. Modesetting is fully algorithmic > (what else?) so you can, if you want, provide your own modeline in the code.
modeline in uboot var? > * sets up simplefb over devicetree which allows the mainline kernel (with > some clocking fixes, see "ARM: clk: sunxi: claim clocks used by simplefb" > patches on our ml) to use the framebuffer set up by u-boot. > > Due to the rather poor console code in u-boot, it is non-trivial to have both > serial and hdmi function as u-boot consoles in parallel. Again, i did not want > to rewrite half u-boot, so the following will need to happen to make it work. > Add: > setenv stdout serial,vga > setenv stderr serial,vga > to your boot.cmd, and you will see the u-boot console. The default environment > also has this. About the keyword "vga", don't ask. > > This version of the patch makes it so that you need to append NO_VIDEO to the > list of board options to disable this code. My feeling is that this logic > will end up getting reversed, so i will need to go touch many boards config > lines (or files, apparently, for mainline). > > simplefb caveat: all the kernel gets is a memory address, and the size and > layout of this memory. There is no two way communication. You do not get DPMS > or anything. If it is on, then it stays on. There is no way to switch modes. > Wait for a full blown display driver for all the normal display driver > goodness. > > Luc Verhaegen. > > -- > You received this message because you are subscribed to the Google Groups > "linux-sunxi" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. -- Jon Smirl [email protected] -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
