50 lines
1.8 KiB
PHP
50 lines
1.8 KiB
PHP
; Copyright (c) 2024 Elaina Claus
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;
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; Permission is hereby granted, free of charge, to any person obtaining a copy
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; of this software and associated documentation files (the "Software"), to deal
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; in the Software without restriction, including without limitation the rights
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; to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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; copies of the Software, and to permit persons to whom the Software is
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; furnished to do so, subject to the following conditions:
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;
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; The above copyright notice and this permission notice shall be included in all
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; copies or substantial portions of the Software.
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;
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; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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; AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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; OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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; SOFTWARE.
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%macro ERROR 1
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xor ax, ax
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mov al, %1
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jmp error
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%endmacro
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; pass error as ascii character in al, errors a-zA-Z or 0-9
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error:
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; fs = 0xb800 => fs:0x0000 = 0xb8000
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mov dx, 0xB800
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mov fs, dx
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mov dx, STEVIA_DEBUG_OK
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cmp ax, dx
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jge error.debug_err
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mov dh, 0x4F ; color 0x4F is white text/red background
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jmp error.print
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.debug_err:
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mov dh, 0x5F ; debug case is white text/purple background
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; the characters are two bytes in the order of 0xb8000: byte c, byte attribute
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; since x86 is le, we store the attribute in the MSB of dx
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.print:
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mov dl, al
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mov word [fs:0x0000], dx
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jmp error.stop
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.stop:
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hlt
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jmp short error.stop |