Am 28.04.2010 08:44, schrieb Wolfgang Denk:
Dear Matthias,
in message4BD7D5DD.6080701@arcor.de you wrote:
- pGD->memSize = VIDEO_MEM_SIZE;
- pGD->frameAdrs = PHYS_SDRAM + PHYS_SDRAM_SIZE - VIDEO_MEM_SIZE;
Please pay attention to the global memory map requirements. PRAM might go first.
Can you please explain this a bit more in detail? I checked the source and README for CONFIG_PRAM and it seems to be reserving some space at the end of RAM. But I have only found reference to it in ppc and m68k code.
Right. But there is a chance that the ARM implementation might be reworked soon, and then it will follow the documented approach as well, so better start correctly from the beginning so you don;t run into conflicts soon.
I totally agree with you, but...
What would be the correct way to reserve some 2MB-4MB at the end of system RAM as a framebuffer for the integrated graphics device?
See the PPC implementation for reference.
I had a look into the PPC code and its clear to me how it is done there. But I currently do not see how this can be done on ARM without a couple of changes to arch/arm/lib/board.c
Another question regarding the video driver: I have seen some video drivers in driver/video/... and some are in arch/.../cpu/...
What would be the right place for mine? As it is integrated into the SoC I tend to put it in arch/arm/cpu/arm/arm926ejs/mb86r0x and not into drivers/video. On the other hand there is a imx31 related video driver in drivers/video.
Thanks for you patience Matthias