2020-06-23 03:32:50 +10:00
|
|
|
# PC/AT
|
2020-06-13 04:01:24 +10:00
|
|
|
|
2020-06-23 03:32:50 +10:00
|
|
|
PC-compatible machines need no introduction. They are one of the most popular
|
|
|
|
|
machines of all time. Collapse OS has a 8086 assembler and has boot code
|
|
|
|
|
allowing it to run on a PC/AT-compatible machine, using BIOS interrupts in
|
|
|
|
|
real mode. Collapse OS always runs in real mode.
|
|
|
|
|
|
|
|
|
|
In this recipe, we will compile Collapse OS and write it to a USB drive that
|
|
|
|
|
is bootable on a modern PC-compatible machine.
|
|
|
|
|
|
|
|
|
|
## Gathering parts
|
|
|
|
|
|
|
|
|
|
* A modern PC-compatible machine that can boot from a USB drive.
|
|
|
|
|
* A USB drive
|
|
|
|
|
|
|
|
|
|
## Build the binary
|
|
|
|
|
|
|
|
|
|
Running `make` in this folder with yield:
|
|
|
|
|
|
|
|
|
|
* mbr.bin: a 512 byte binary that goes at the beginning of the disk
|
|
|
|
|
* os.bin: 8086 Collapse OS binary
|
|
|
|
|
* disk.bin: a concatenation of the above, with `blkfs` appended to it starting at
|
|
|
|
|
`0x2000`.
|
|
|
|
|
|
|
|
|
|
`disk.bin` is what goes on the drive.
|
|
|
|
|
|
|
|
|
|
This binary has `BLK` and `AT-XY` support, which means you have disk I/Os and
|
|
|
|
|
can run `VE`.
|
|
|
|
|
|
|
|
|
|
## Emulation
|
|
|
|
|
|
2020-10-26 01:27:52 +11:00
|
|
|
You can run the built binary in Collapse OS' 8086 emulator using `make emul`.
|
|
|
|
|
|
|
|
|
|
The 8086 emulator is barbone. If you prefer to use it on a more realistic
|
|
|
|
|
setting, use QEMU. The command is:
|
|
|
|
|
|
|
|
|
|
qemu-system-i386 -drive file=disk.bin,if=floppy,format=raw
|
2020-06-23 03:32:50 +10:00
|
|
|
|
|
|
|
|
## Running on a modern PC
|
|
|
|
|
|
|
|
|
|
First, copy `disk.bin` onto your USB drive. For example, on an OpenBSD machine,
|
|
|
|
|
it could look like:
|
|
|
|
|
|
|
|
|
|
doas dd if=disk.bin of=/dev/sd1c
|
|
|
|
|
|
|
|
|
|
Your USB drive is now BIOS-bootable. Boot your computer and enter your BIOS
|
|
|
|
|
setup to make sure that "legacy boot" (non-EFI boot, that is, BIOS boot) is
|
|
|
|
|
enabled. Configure your boot device priority to ensure that the USB drive has
|
|
|
|
|
a chance to boot.
|
|
|
|
|
|
|
|
|
|
Reboot, you have Collapse OS. Boot is of course instantaneous (we're not used
|
|
|
|
|
to this with modern software...).
|
