What steps will reproduce the problem? 1. Make VHD disk image 767 MB with Windows 7 diskpart. VHD footer geometry is H/S = 16/63 2. Create a primary partition with Windows 7 diskpart or disk management and format NTFS. MBR,PBR geometry is H/S = 255/63 4. Attach VHD to VirtualBox VM as second disk and another disk with grub4dos installed as first disk. 5. Boot VM. From VirtualBox Log 00:00:00.669 Guest Log: BIOS: ata0-1: PCHS=779/16/63 LCHS=779/32/63 BIOS geometry is H/S = 32/63 6. grub> map --harddrives=2
(write 2 to address 0x475 which has wrong value 1 when in VirtualBox) 7. grub> debug 2 grub> geometry (hd1) grub> geometry --tune --sync (hd1) grub> geometry (hd1)

What is the expected output? GRUB4DOS geometry is the same as BIOS int13/AH=8 geometry.

What do you see instead? BIOS int13/AH=8 reports 779/32/63. GRUB4DOS geometry is still unchanged 98/255/63.

--tune fail to detect the correct geometry that BIOS use.

MBR geometry and BIOS geometry can disagree when user move disk between (virtual) machine. I want to add an option of geometry command that user can use to tell GRUB4DOS to use geometry reported by BIOS to update MBR,PBR with --sync.

thanks.already apply this patch at r68.

Previous patch add geometry --bios option to allow user to force use of BIOS reported geometry.

This patch fix geometry_tune function (called by geometry --tune) that previously return wrong result when number of heads and number of sectors calculated from MBR exceed correct numbers.

Ok,will patch next version.