On Sun, Nov 15, 2009 at 10:16 PM, Stefan Weil <w...@mail.berlios.de> wrote: > malc schrieb: >> On Sun, 15 Nov 2009, Gleb Natapov wrote: >> >>> On Sun, Nov 15, 2009 at 06:22:40PM +0300, malc wrote: >>>> On Sun, 15 Nov 2009, Blue Swirl wrote: >>>> >>>>> On Sun, Nov 15, 2009 at 3:25 AM, malc <av1...@comtv.ru> wrote: >>>>>> debian-503-i386-netinst.iso when booted on a machine with `-vga >>>>>> std' just >>>>>> shows black screen (after bios' setup screen) >>>>> Just some observations: >>>>> - if you press enter, installer starts and Linux is able to fix the >>>>> display >>>>> - the screen is fine with -bios pcbios.bin, so the issue is related >>>>> to SeaBIOS >>>> Yes i forgot to mention that -bios works, also worth noting is that >>>> before >>>> the commit that fixed cirrus -bios hack also made it work. > > > Here is a summary of my analysis of this problem: > > Graphics mode memory (ram 0xe0000000 ...) is not mapped > in QEMU address space (which results in unassigned > memory writes) for standard pci vga (-vga std), so users > don't get vga display output with grub (in graphical mode), > debian installer (in graphical mode) or similar boot software. > > This happens for PC system emulation using SeaBIOS. > It won't happen when using Bochs BIOS. > > Other system emulations which can run standard pci vga > seem to suffer from the same problem: when I run mips > malta using -vga std, it won't display anything on the vga > screen (it works with cirrus pci vga). > > Malta has no vga bios, so the error might be in QEMU's > vga code (hw/vga-pci.c). Maybe wrong initial PCI mappings? > Maybe this has always be wrong (which would explain why > git bisect does not work). > > pci_vga_init() is called by sun4u, ppc_prep, ppc_oldworld, > ppc_newworld, pc and mips, so all these emulations > share the same potential problem.
At least sun4u, ppc_oldworld and ppc_newworld are fine with -vga std. There is no VGA BIOS.
