On Sun, Nov 15, 2009 at 11:21 PM, malc <av1...@comtv.ru> 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 history - 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