cosmopolitan/tool/build/lib/ioports.c

98 lines
3.4 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│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/struct/iovec.h"
#include "libc/nexgen32e/uart.internal.h"
#include "libc/sysv/consts/fileno.h"
#include "tool/build/lib/ioports.h"
static int OpE9Read(struct Machine *m) {
int fd;
uint8_t b;
fd = STDIN_FILENO;
if (fd >= m->fds.i) return -1;
if (!m->fds.p[fd].cb) return -1;
if (m->fds.p[fd].cb->readv(m->fds.p[fd].fd, &(struct iovec){&b, 1}, 1) == 1) {
return b;
} else {
return -1;
}
}
static void OpE9Write(struct Machine *m, uint8_t b) {
int fd;
fd = STDOUT_FILENO;
if (fd >= m->fds.i) return;
if (!m->fds.p[fd].cb) return;
m->fds.p[fd].cb->writev(m->fds.p[fd].fd, &(struct iovec){&b, 1}, 1);
}
static int OpSerialIn(struct Machine *m, int r) {
switch (r) {
case UART_DLL:
if (!m->dlab) {
return OpE9Read(m);
} else {
return 0x01;
}
case UART_LSR:
return UART_TTYDA | UART_TTYTXR | UART_TTYIDL;
default:
return 0;
}
}
static void OpSerialOut(struct Machine *m, int r, uint32_t x) {
switch (r) {
case UART_DLL:
if (!m->dlab) {
return OpE9Write(m, x);
}
break;
case UART_LCR:
m->dlab = !!(x & UART_DLAB);
break;
default:
break;
}
}
uint64_t OpIn(struct Machine *m, uint16_t p) {
switch (p) {
case 0xE9:
return OpE9Read(m);
case 0x3F8 ... 0x3FF:
return OpSerialIn(m, p - 0x3F8);
default:
return -1;
}
}
void OpOut(struct Machine *m, uint16_t p, uint32_t x) {
switch (p) {
case 0xE9:
OpE9Write(m, x);
break;
case 0x3F8 ... 0x3FF:
OpSerialOut(m, p - 0x3F8, x);
break;
default:
break;
}
}