56 lines
2.6 KiB
C
56 lines
2.6 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "ape/lib/pc.h"
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#include "libc/calls/internal.h"
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#include "libc/nexgen32e/uart.internal.h"
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static bool IsDataAvailable(struct Fd *fd) {
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return inb(fd->handle + UART_LSR) & UART_TTYDA;
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}
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static int GetFirstIov(struct iovec *iov, int iovlen) {
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int i;
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for (i = 0; i < iovlen; ++i) {
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if (iov[i].iov_len) {
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return i;
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}
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}
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return -1;
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}
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ssize_t readv$serial(struct Fd *fd, const struct iovec *iov, int iovlen) {
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size_t i, j, got = 0;
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if ((i = GetFirstIov(iov, iovlen)) != -1) {
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while (!IsDataAvailable(fd)) asm("pause");
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i = 0;
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j = 0;
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do {
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++got;
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((char *)iov[i].iov_base)[j] = inb(fd->handle);
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if (++j == iov[i].iov_len) {
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j = 0;
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if (++i == iovlen) {
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break;
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}
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}
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} while (IsDataAvailable(fd));
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}
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return got;
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}
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