Thread (5 messages) 5 messages, 4 authors, 2001-01-25

Re: [linux-fbdev] Matrox and XFree86 4.0.2 update

From: Kostas Gewrgiou <hidden>
Date: 2001-01-25 11:08:24

On Thu, 25 Jan 2001, Geert Uytterhoeven wrote:
On Thu, 25 Jan 2001, Kostas Gewrgiou wrote:
quoted
On Wed, 24 Jan 2001, Petr Vandrovec wrote:

Nope it won't cause any problems, none of the XF[86][68]_FBDev servers where
accelerated for matrox, other libs (SDL etc) that have accel for matroxfb
don't work correctly for ppc either.
XF68_FBDev is accelerated for matroxfb, at least on the PPC platform.
Ops i forgot about it, it will be easy to change it though, although
backwards compatibility will be a nightmare :(
quoted
Changing the endian to little is the *right* thing, big-endian mode doesn't
offer us anything beyond problems in matroxfb 8/16 bit accesses become a
nightmare there...
8/16 bit accesses? I assume you're talking about the frame buffer, not about
the register accesses?
No i am talking about register accesses, for example
the mga driver in xfree86 uses
 #define MGAISBUSY() (INREG8(MGAREG_Status + 2) & 0x01)
SDL uses
 #define mga_wait(space)  {                                             \
        while ( mga_in8(MGAREG_FIFOSTATUS) < space );                   \
 }

Both will fail under big-endian mode in PPC, the addressing is changed
so you have to use something like *(addr + (3-addr%4) to get the right
byte (i hope i got it right, its still early here)
Currently XF68_FBDev needs a big-endian frame buffer on big-endian machines.
And i don't expect it to change ;P

 Kostas


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