[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] Standard vga breakage

From: Blue Swirl
Subject: Re: [Qemu-devel] Standard vga breakage
Date: Sun, 15 Nov 2009 23:35:29 +0200

On Sun, Nov 15, 2009 at 11:21 PM, malc <address@hidden> wrote:
> On Sun, 15 Nov 2009, Stefan Weil wrote:
>> malc schrieb:
>> > On Sun, 15 Nov 2009, Gleb Natapov wrote:
> [..snip..]
>> 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).
> git bisect doesn't work because most of the time:
> a. Compilation fails
> b. Compilation succeeds but qemu segfaults before even trying to
>   execute any guest code

With infinite time and resources, we could construct a fully
bisectable tree with the following properties:
- buggy commits (especially commits that break build or require manual
reconfiguration) are replaced with corrected commits by changing the
- no merges, linear history
- compound commits are broken down to simple, atomic versions
- documentation is added by the first commit to reduce the number of commits
- spelling fixes applied by changing history, not as a separate commit
- each commit should still have some relation to some real tree commit

reply via email to

[Prev in Thread] Current Thread [Next in Thread]