[RPI BSP] fbcon implementation

Gedare Bloom gedare at gwu.edu
Wed Jun 3 14:10:41 UTC 2015

On Tue, Jun 2, 2015 at 5:45 PM, Pavel Pisa <ppisa4lists at pikron.com> wrote:
> Hello Yang Qiao,
> On Tuesday 02 of June 2015 22:58:09 QIAO YANG wrote:
>> 2. The mmu configuration for framebuffer. I'm still confused about how to
>> deal with it.
>>     Is there anyway to setup the memory in the code ? For exemple: after
>> detected the size and start point of framebuffer, setup a given block
>> (range) to  ARMV7_MMU_DATA_READ_WRITE in the code?
>>    I prefer to setup the mmu table after the fb initialized. If it's not
>> possible, like we've discussed earlier, we should enable all possible area
>> at startup. Since the start point varies for different devices, how can I
>> find out the pages to be activate?
> I believe that it is possible if space in page table is reserved at startup.
Find the mmu_config_table or whatever it's called there. So far RTEMS
only supports a static mapping at startup, so it is best to know what
the address range will be at compile- or link-time.

>> 3. Not like in i386, I've got to take a ascii font file for drawing
>> characters. I've taken the hard cored 8*16 font from UBOOT code. I think
>> maybe we can move the font file in a common directory for all bsps. It's
>> not so important, just a suggestion. Also the EDID header may be moved for
>> all bsps as well.
> I agree and suggest to put EDID header files to shared place where
> all BSPs can select/enable their copy to installed include files
> location.
> I expect, that next location is right
>   rtems/c/src/lib/libbsp/shared/include

> The font(s) should be moved to BSP independent location as well.
> So I agree with proposal. I am not sure about the best location.
> The location should be negotiated with RTEMS core developers ...
> Joel, Chris, Gedare, Sebastian. I suggest next location to have
> some start point for discussion
>   rtems/c/src/lib/libbsp/shared/fonts
I have no problem with this location.

> The U-boot taken file license can be a problem. But we have
> had tool to generate Micro Windows compatible font from
> TTF fonts and there are MPL or even less restrictive licensed
> fixed size fonts in Microwindows for example.
> So finding reasonable font wit suitable license should not be
> a problem.
Yes, check the licenses carefully before you copy code (including
fonts), or identify where the code comes from and ask someone else to
evaluate for you. Pure GPL and LGPL code is not acceptable.


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