71 lines
1.2 KiB
C
71 lines
1.2 KiB
C
/*
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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 <unistd.h>
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#include "semihost_syscall.h"
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#include "semihost_fdtable.h"
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extern int errno;
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/* Set position in a file. */
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off_t
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_lseek (int file, off_t offset, int dir)
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{
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long data_block[2];
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long flen;
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long res;
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struct fdentry *fd;
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off_t abs_pos;
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fd =__get_fdentry (file);
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if (fd == NULL)
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{
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errno = EBADF;
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return -1;
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}
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if (dir == SEEK_CUR && offset == 0)
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return fd->pos;
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data_block[0] = fd->handle;
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switch (dir)
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{
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case SEEK_SET:
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abs_pos = offset;
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break;
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case SEEK_CUR:
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abs_pos = fd->pos + offset;
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break;
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case SEEK_END:
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data_block[1] = 0;
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flen = syscall_errno (SEMIHOST_flen, data_block);
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if (flen == -1)
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return -1;
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abs_pos = flen + offset;
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break;
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default:
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errno = EINVAL;
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return -1;
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}
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if (abs_pos < 0)
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{
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errno = EINVAL;
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return -1;
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}
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data_block[1] = abs_pos;
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res = syscall_errno (SEMIHOST_seek, data_block);
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if (res == 0)
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{
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fd->pos = abs_pos;
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return abs_pos;
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}
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return res;
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}
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