51 lines
1.1 KiB
Forth
51 lines
1.1 KiB
Forth
# x86 Device Drivers
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This exposes the low level port I/O device to RETRO. These
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will be used in the implementation of the device drivers.
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~~~
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{{
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'io:X86 var
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:identify
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@io:X86 n:zero? [
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#2000 io:scan-for dup n:negative?
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[ drop 'IO_DEVICE_TYPE_2000_NOT_FOUND s:put nl ]
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[ !io:X86 ] choose ] if ;
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---reveal---
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:io:x86 identify @io:X86 io:invoke ;
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}}
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~~~
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# I/O Ports
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~~~
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:pio:in-byte (p-n) #0 io:x86 ;
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:pio:out-byte (vp-) #1 io:x86 ;
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~~~
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# Access to Physical RAM
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~~~
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:ram:store (va-) #2 io:x86 ;
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:ram:fetch (a-v) #3 io:x86 ;
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:ram:store-byte (va-) #4 io:x86 ;
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:ram:fetch-byte (a-v) #5 io:x86 ;
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~~~
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# Hexadecimal
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Since most resources list the values and ports in hex, I
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am defining a prefix to be used. This will allow for hex
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values to be specified like `0xC3`. They must be caps, and
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negative values are not supported.
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~~~
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{{
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'Number var
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'0123456789ABCDEF 'DIGITS s:const
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:convert (c-) &DIGITS swap s:index-of @Number #16 * + !Number ;
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---reveal---
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:prefix:0 (s-n)
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n:inc #0 !Number [ convert ] s:for-each @Number class:data ; immediate
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}}
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~~~
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