On Sun, May 29, 2011 at 1:55 PM, <cinap_len...@gmx.de> wrote: > Hi, > > working on a bootloader, we added apm initialization code to the bootloader > so the kernel doesnt have to switch to realmode and can just do 32 protected > mode calls. > > the bootloader does the following things in realmode before starting the > kernel: > > 1) do apm installation check (INT 0x15, AX=0x5300) > 2) do apm disconnect (INT 0x15, AX=0x5304) > 3) do apm connect to 32bit protected mode interface (INT 0x15, AX=0x5303, > BX=0) > 4) save and pass the register contents after the connect call in some form to > the kernel > > but doing this seems to disable VESA bios functionality on some machines (via > epia > and p3-sbc) (INT 0x10, AX=0x4F00 doesnt return any modes) > > i dont have the machines where this happens and i dont know the exact return > conditions of the vbe calls yet, but i plan to debug this using our realmode > emulator > but it might take us some time... > > my question is are we on the right track? is it possible that doing these APM > calls disables VBE? > > -- > cinap >
Hi cinap, It sounds like you may have an interrupt vector chaining problem or register corruption problem in you interrupt installation. Marc -- http://se-eng.com -- coreboot mailing list: coreboot@coreboot.org http://www.coreboot.org/mailman/listinfo/coreboot
