cosmopolitan/libc/vga/writev-vga.c

84 lines
4.1 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│
╞══════════════════════════════════════════════════════════════════════════════╡
│ This is free and unencumbered software released into the public domain. │
│ │
│ Anyone is free to copy, modify, publish, use, compile, sell, or │
│ distribute this software, either in source code form or as a compiled │
│ binary, for any purpose, commercial or non-commercial, and by any │
│ means. │
│ │
│ 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 │
│ relinquishment in perpetuity of all present and future rights to this │
│ software under copyright law. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, │
│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF │
│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. │
│ IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR │
│ OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, │
│ ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR │
│ OTHER DEALINGS IN THE SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/struct/fd.internal.h"
#include "libc/calls/struct/iovec.h"
#include "libc/calls/struct/iovec.internal.h"
#include "libc/dce.h"
#include "libc/vga/vga.internal.h"
#include "libc/runtime/pc.internal.h"
#include "libc/str/str.h"
#ifdef VGA_USE_WCS
static wchar_t vga_wcs[VGA_TTY_HEIGHT * VGA_TTY_WIDTH];
#else
static wchar_t * const vga_wcs = NULL;
#endif
struct Tty _vga_tty;
ssize_t sys_writev_vga(struct Fd *fd, const struct iovec *iov, int iovlen) {
size_t i, wrote = 0;
ssize_t res = 0;
for (i = 0; i < iovlen; ++i) {
void *output = iov[i].iov_base;
size_t len = iov[i].iov_len;
res = _TtyWrite(&_vga_tty, output, len);
if (res < 0)
break;
wrote += res;
if (res != len)
return wrote;
}
if (!wrote)
return res;
return wrote;
}
__attribute__((__constructor__)) static textstartup void _vga_init(void) {
if (IsMetal()) {
void * const vid_buf = (void *)(BANE + 0xb8000ull);
/*
* Get the initial cursor position from the BIOS data area. Also get
* the height (in scan lines) of each character; this is used to set the
* cursor shape.
*/
typedef struct {
unsigned char col, row;
} bios_curs_pos_t;
bios_curs_pos_t pos = *(bios_curs_pos_t *)(BANE + 0x0450ull);
uint8_t chr_ht = *(uint8_t *)(BANE + 0x0485ull),
chr_ht_hi = *(uint8_t *)(BANE + 0x0486ull);
if (chr_ht_hi != 0 || chr_ht > 32)
chr_ht = 32;
/*
* Initialize our tty structure from the current screen contents,
* current cursor position, & character height.
*/
_StartTty(&_vga_tty, VGA_TTY_HEIGHT, VGA_TTY_WIDTH, pos.row, pos.col,
chr_ht, vid_buf, vga_wcs);
}
}