Hello Mark and Xpert list Do you happen to have an email address for Egbert Eich handy?
Actually I already have the two video cards working as I suggested in my previos email. To do so took a lot of work. And to do so I needed to get a datasheet from ATI to accomplish control of the AGP card via my kernel module. This limits me to the ATI Radeon 7500 card only. I would like to branch out to other cards as well in case ATI can not continue provide me with docs for their newer cards. So now I am wondering if their exists a way to write to the legacy ports using an address something like base_address + legacy_port_offset where legacy address would possibly be obtained from PCI config-space. Any help appreciated, Daniel >> Hello Expert lixt >> >> Does anyone know if there is a standard way to access legacy VGA >>registers through mappe-memory registers in most video cards. I > It\\\'s not standard. I think nearly all cards can do it, and >there are some similarities between a subset of cards, but there\\\'s >no standard way, either in where the registers are mapped or >how they are laid out within that mapping. >> am asking this question because in woul like to be able to driver >> a PCI card with the normal Xserver while driving an AGP card with >> a custom driver. The custom driver would make use of legacy addresses >> but doing this without altering the behavior of both cards is >> my problem. >> > As two separate processes this will be difficult. Even for >an XFree86 driver that can manage without doing any port I/O, >and many are that way, you still need legacy access to save >the fonts. Perhaps if the Xserver was on the secondary card >so it didn\\\'t have to save fonts, it might never need to touch >the legacy vga. But still, there probably needs to be some >X-server hacking to keep XFree86 from disabling access to your >vga card. I think in many cases it probably proactively pulls >the other card off of the bus to keep it from interfering with >the operating X-server. Egbert Eich is the expert in this area. >XFree86 actually has a mechanism where it can run N cards that >only do port I/O to legacy registers simultaneously. It does >this by enabling and disabling access at appropriate times. >But these are all managed within the same process so it can >keep track of this stuff. A third party would complicate things. > Mark. _______________________________________________ Xpert mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/xpert
