Description of problem: GRUB has two builtin commands "vbeprobe" and "testvbe" which are intended to test VESA VBE BIOS graphics modes (e.g. for manually testing the correct Linux VESA framebuffer mode before setting the vga= kernel command line value). However, on many recent graphics cards which are VESA 3.0 compliant these commands do not work. The reason is a wrong definition of the vbe_mode structure in stage2/shared.h. The VBE mode info structure should be 256 bytes long, but here it is actually only 255 bytes long, the array "unsigned char reserved3[189]" should be actually declared as "unsigned char reserved3[190]" (frankly, the same mistake is also present in the official VESA VBE 3.0 specification document). As the vbe_mode structure is allocated on stack in vbeprobe_func() and testvbe_func() (stage2/builtins.c), if the VESA BIOS actually stores all 256 bytes in the 0x4f01 call (Get Mode Info), the last byte overruns the structure and ends in a different variable on the stack (mode_number in case of vbeprobe_func()), thus rendering both routines unfunctional. Version-Release number of selected component (if applicable): grub-0.97-68.fc14.x86_64 (affects probably all releases of GRUB Legacy) How reproducible: Always on many recent graphics cards with VGA BIOS compliant to VESA VBE 3.0 which actually store 256 bytes in the 0x4f01 call. Steps to Reproduce: 1. While in GRUB (during boot time) go to the command line. 2. Try using the "vbeprobe" or "testvbe" commands. Actual results: No list of supported VESA modes is printed and no VESA mode can be tested (even those which are definitively supported by the hardware). Expected results: The "vbeprobe" should print out a list of supported VESA modes and "testvbe" should be able to test them.
Created attachment 461753 [details] Patch changing the size of "struct vbe_mode" to 256 bytes
This message is a notice that Fedora 14 is now at end of life. Fedora has stopped maintaining and issuing updates for Fedora 14. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At this time, all open bugs with a Fedora 'version' of '14' have been closed as WONTFIX. (Please note: Our normal process is to give advanced warning of this occurring, but we forgot to do that. A thousand apologies.) Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, feel free to reopen this bug and simply change the 'version' to a later Fedora version. Bug Reporter: Thank you for reporting this issue and we are sorry that we were unable to fix it before Fedora 14 reached end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged to click on "Clone This Bug" (top right of this page) and open it against that version of Fedora. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete. The process we are following is described here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping