newlib-cygwin/libgloss/riscv/semihost_syscall.h

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2020-12-15 20:00:27 +08:00
/*
* Copyright (C) 2020 Embecosm Limited
* SPDX-License-Identifier: BSD-2-Clause
*/
#ifndef _INTERNAL_SYSCALL_H
#define _INTERNAL_SYSCALL_H
extern int errno;
static inline long
__semihost_syscall (long id, long *data_block)
{
register long a0 asm ("a0") = id;
register long a1 asm ("a1") = (long) data_block;
/* RISC-V semihosting trap sequence. Must be uncompressed and must not
cross page boundary. */
asm volatile (
".balign 16 \n"
".option push \n"
".option norvc \n"
"slli zero, zero, 0x1f \n"
"ebreak \n"
"srai zero, zero, 0x7 \n"
".option pop \n"
: "+r"(a0) : "r"(a1) : "memory");
return a0;
}
static inline long
__syscall_error ()
{
errno = __semihost_syscall (SEMIHOST_errno, 0);
return -1;
}
static inline long
syscall_errno (long id, long *data_block)
{
long res = __semihost_syscall (id, data_block);
if (res < 0)
return __syscall_error ();
return res;
}
#endif