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