41 lines
1.3 KiB
Plaintext
41 lines
1.3 KiB
Plaintext
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# $Source$
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# $State$
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# $Revision$
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The pc86 platform
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=================
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pc86 is an i86-based BSP that produces bootable floppy disk images that can
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be run on most PCs. It is intended to be quick and dirty rather than actually
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useful, although it may come in handy for hardware test purposes, boot
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loaders, and the like.
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The code runs in TINY mode, where CS, DS and SS all share the same segment.
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This means that there's not very much memory available. It would be very easy
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to change it to run in SMALL mode, where CS occupies one segment and DS and SS
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another, which would give 64kB for nearly all programs; I just haven't done it.
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IEEE floating point is available, but requires an FPU.
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This port only implements a very limited set of syscalls --- and most of those
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are stubs required to make the demo apps link. File descriptors 0, 1 and 2
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represent the console. All reads block. There's enough TTY emulation to allow
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\n conversion and local echo (but it can't be turned off).
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Console output is echoed to the serial port (without any setup). This is used
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by qemu for running tests.
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Example command line
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====================
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ack -mpc86 -O -o pc86.img examples/paranoia.c
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The file pc86.img can then be copied onto a floppy and booted, or run via qemu
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or somesuch emulator.
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David Given
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dg@cowlark.com
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