Qemu
Qemu is an open source processor emulator. It emulates a variety of different CPUs and systems, and achieves good speed by using dynamic translation.
Reference
Articles
- Qemu on Linux: setting up and using Qemu under Linux
- Win98 in Qemu: installing and running Windows 98 inside Qemu
Notes
Creating the disk image
qemu-img create win98hd.img 2G qemu -hda win98hd.img -cdrom win98.iso -boot d
Accessing the disk image from Linux
In general, assuming the image file was made with the default disk head/sector parameters:
sudo mount -o loop,offset=32256 /path/to/image /path/to/directory/
Specific example (Woozle's system):
sudo mount -o loop,offset=32256 /home/woozle/win98/c.img /mnt/qemu
The reason for the offset is that the image represents an entire disk; you can only mount a partition, not the entire disk. The offset is where the main partition starts. You can find out where partitions are in a disk image by using fdisk:
fdisk /path/to/image
Woozle example:
fdisk /home/woozle/win98/c.img
This takes you to a menu, where you type "p" to get a partition table:
Command (m for help): p Disk c.img: 0 MB, 0 bytes 64 heads, 63 sectors/track, 0 cylinders Units = cylinders of 4032 * 512 = 2064384 bytes Device Boot Start End Blocks Id System c.img1 * 1 520 1048288+ c W95 FAT32 (LBA)
Based on what I worked out below (which you don't need to read unless that sort of thing interests you), you work this equation to find the correct offset:
[Start] x [bytes-per-sector] x [sectors/track]
...where [bytes-per-sector] is the number after the "*" in "cylinders of..."
(Working backwards from the knowledge that 32256 – which was a Magic Number found by Tenebram – is the correct number, and trying to figure out why it is correct: If we presume that "sectors/track" means the number of sectors per track for a single head, then 4032 (which is 64 x 63) must be the number of sectors per track for all heads, and 512 is probably the sector size in bytes. The offset to a given sector, then (waving a magic wand at all this so that it matches reality somehow) is [start] x [bytes-per-sector] x [sectors-per-track] – which leads us to deduce that the units for the [start] number must be "tracks".)
Accelerator
For linux host systems, there is a loadable kernel module (called kqemu) that will allow qemu to run at near native speeds. At the time of this writing, there aren't distributed packages available with the module built, so you'll need to download the source from the website and compile it locally.
First download the qemu source and untar it. Then download the kqemu source and untar it within the qemu source directory. Then run ./configure && make && sudo make install. You might also want to install the vgabios package from your package manager.
Editor's note: I had this -- "If you're wanting to run Windows 98 under qemu, this option is moot because kqemu and Win98 don't get along." written here, but I think that only applies to kqemu and maybe qemu-fast (I'm not clear on what the difference is between the two).