33 lines
676 B
C
33 lines
676 B
C
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/*
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* Copyright (C) 2020 Embecosm Limited
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <machine/syscall.h>
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#include <errno.h>
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#include <sys/types.h>
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#include "semihost_syscall.h"
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#include "semihost_fdtable.h"
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/* Read from a file. */
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ssize_t _read (int file, void *ptr, size_t len)
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{
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struct fdentry *fd =__get_fdentry (file);
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long data_block[3];
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long res;
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if (fd == NULL)
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return -1;
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data_block[0] = fd->handle;
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data_block[1] = (long) ptr;
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data_block[2] = len;
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res = syscall_errno (SEMIHOST_read, data_block);
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if (res >= 0)
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{
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ssize_t bytes_read = len - res;
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fd->pos += bytes_read;
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return bytes_read;
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}
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return -1;
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}
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