cosmopolitan/libc/vga/tty-graph.c
tkchia d3efa47f81
Show "screen of death" on VGA console upon program crash (#650)
* [metal] Refactoring: separate out sys_writev_vga() and _vga_init() modules

* [metal] Read VGA info from BDA before long mode entry, not after

If using a pre-existing VGA text console, the VGA initialization
code now retrieves the cursor position & character height from
the BIOS data area while still in real mode — rather than
reading from the BIOS data area only after entering long mode.

(This should help make the code more correct, if Cosmopolitan
were to support UEFI graphics output in the future.  If the
program were booted via UEFI, then the long mode IsMetal()
code would still be activated, but the BIOS data area might
not have been initialized in that case.)

This change also means that there are now a few more fields
in the `struct mman`.

* [metal] VGA console can now show "screen of death" upon a crash

There is now a new function _klog_vga(), which can be called
by kprintf() to output system messages — e.g. information about
CPU exceptions — on the VGA screen.

* [metal] CPU exception handler now dumps cr2 value
* [metal] Add demo of program crash reporting w/ bare metal VGA TTY
* [metal] Reduce size of "screen of death" code
2022-10-06 05:36:15 -07:00

54 lines
3.2 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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│ This is free and unencumbered software released into the public domain. │
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│ distribute this software, either in source code form or as a compiled │
│ binary, for any purpose, commercial or non-commercial, and by any │
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│ In jurisdictions that recognize copyright laws, the author or authors │
│ of this software dedicate any and all copyright interest in the │
│ software to the public domain. We make this dedication for the benefit │
│ of the public at large and to the detriment of our heirs and │
│ successors. We intend this dedication to be an overt act of │
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│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, │
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╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/intrin/newbie.h"
#include "libc/macros.internal.h"
#include "libc/str/str.h"
#include "libc/vga/vga.internal.h"
/**
* @fileoverview Instantiation of routines for normal console output in
* graphical video modes.
*
* @see libc/vga/tty-graph.inc
*/
#undef KLOGTTY
#define MAYUNROLLLOOPS unrollloops
#define COLOR TtyCanvasColor
#define BPP 32
#define MAPCOLOR TtyGraphMapColor
#define DIRTY TtyGraphDirty
#undef UPDATE
#define RESETDIRTY TtyGraphResetDirty
#define DRAWBITMAP TtyGraphDrawBitmap
#define FILLRECT TtyGraphFillRect
#define MOVERECT TtyGraphMoveRect
#define DRAWCHAR _TtyGraphDrawChar
#define ERASELINECELLS _TtyGraphEraseLineCells
#define MOVELINECELLS _TtyGraphMoveLineCells
#include "libc/vga/tty-graph.inc"