[U-Boot-Users] PCI video display in MPC8270
Hi All,
We currently just enabled the PCI bus on our MPC8270 custom board. We intend to put a video chip in the PCI bus (XGI Volari Z7). For testing, we got the Z7 PCI demo board. We are using u-boot and Linux kernel 2.4.25 in our system. I had a pre-conception that the Linux kernel will be able to handle the VGA console by itself without any BIOS help (or in this case U-boot). After configuring the kernel to support VGA console, the PCI video card did not give any display (probably no sync at all). AFAIK, the PCI bus is working correctly. I did test a Netgear PCI network card to verify it (and it passed).
The Z7 demo card works ok on a regular Linux PC with a standard BIOS on it.
1. Does our system require a VGA BIOS (aside from U-boot) to display console (and later on to display a GUI, i.e. X Windows, Tiny X)?
2. Is it possible to configure the Kernel to do the PCI video card initialization without involving U-boot so that it will at least display a VGA console 80x25?
3. Do I actually need to write a driver for the Z7 in U-boot (similar to CT9000, SMI 710/712/810) to configure the video chip correctly before Linux takes over?
4. I still like to send U-boot console messages to the MPC8270 (SCC) serial port and just start the VGA console once Linux takes over. Is this possible?
I greatly appreciate any insights about this issue.
thanks in advance, Maynard
Hello,
in message 38948EB93E24844E9911E0E932C0466470B1CC@plum.raritan.com you wrote:
- Does our system require a VGA BIOS (aside from U-boot) to display
console (and later on to display a GUI, i.e. X Windows, Tiny X)?
Probably yes; alternatively you can try an enable the x86 emulation code in U-Boot and use this to run the card BIOS init code.
- Is it possible to configure the Kernel to do the PCI video card
initialization without involving U-boot so that it will at least display a VGA console 80x25?
Everthing is possible, if you spend enough effort on it. In this case you will probably need some form of x86 emulation in Linux.
- Do I actually need to write a driver for the Z7 in U-boot (similar to
CT9000, SMI 710/712/810) to configure the video chip correctly before Linux takes over?
YOu probably don't need a graphics driver but somce code to initialize the card, either in U-Boot or in Linux. Given the fact that you will most probably have to run the card's BIOS code yuou need an x86 emulation. This is easier in the U-Boot context than in Linux.
- I still like to send U-boot console messages to the MPC8270 (SCC)
serial port and just start the VGA console once Linux takes over. Is this possible?
Yes, of course.
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Best regards,
Wolfgang Denk
participants (2)
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Maynard Cabiente -
Wolfgang Denk