On Tue, 22 Apr 2008, Scott D. Davilla wrote:

quoted

On Tue, 22 Apr 2008, Scott D. Davilla wrote:

quoted

 >On Tue, 22 Apr 2008, Benjamin Herrenschmidt wrote:
 >>  We currently have a problem with those two members of struct
 >>  fb_fix_screeninfo. The struct contains an "unsigned long" which means
 >>  that:
 >>
 >>  - 64 bits kernels with 32 bits userspace can't pass a complete
address
 >>  - 32 bits machines with 64 bits resource_size_t can't pass a complete
 >>  address
 >>  - The structure isn't even properly padded to be 32/64 bits neutral
in
 >>  the first place.
 >>
 >  > We could define new versions of the struct with new get/set ioctls,
 >>  or we could try to just deprecate those fields. What do you guys
think ?
 >
 >As userspace doesn't really need those fields[1], we can easily
 >deprecate them.

 > kexec uses FBIOGET_FSCREENINFO and FBIOGET_VSCREENINFO. So if these
 > ioctls changes, it will possibly break kexec under vesafb and efifb.

Does kexec use the smem_start and mmio_start fields of
fb_fix_screeninfo?

In "kexec/arch/i386/x86-linux-setup.c", the routine "setup_linux_vesafb" uses
smem_start, smem_len, and line_length.

This is used for vesafb and efifb framebuffer kernel boot param setup. This is
required for PC hardware that do not contain a PC-BIOS and need the bootloader
to setup the kernel video boot params.

OK, but the problem doesn't show up on x86-32 (no >32-bit physical
addresses yet), as x86_linux_param_header.lfb_base is uint32_t and there's no
way it's gonna change.

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

-------------------------------------------------------------------------
This SF.net email is sponsored by the 2008 JavaOne(SM) Conference 
Don't miss this year's exciting event. There's still time to save $100. 
Use priority code J8TL2D2. 
http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone