risc-v: initial 64 bit port, static only (no TLS/NPTL)

Only a simple hello world is tested in qemu system emulation.

1 files changed, 125 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/riscv64/sysdep.h b/libc/sysdeps/linux/riscv64/sysdep.h
new file mode 100644
index 000000000..b12329332
--- /dev/null
+++ b/libc/sysdeps/linux/riscv64/sysdep.h
@@ -0,0 +1,125 @@
+/* Assembly macros for RISC-V.
+   Copyright (C) 2011-2018
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _LINUX_RISCV_SYSDEP_H
+#define _LINUX_RISCV_SYSDEP_H 1
+
+#include <common/sysdep.h>
+
+#ifdef __ASSEMBLER__
+
+# include <sys/asm.h>
+
+# define ENTRY(name) LEAF(name)
+
+# define L(label) .L ## label
+
+/* Performs a system call, handling errors by setting errno.  Linux indicates
+   errors by setting a0 to a value between -1 and -4095.  */
+# undef PSEUDO
+# define PSEUDO(name, syscall_name, args)			\
+  .text;							\
+  .align 2;							\
+  ENTRY (name);							\
+  li a7, SYS_ify (syscall_name);				\
+  scall;							\
+  li a7, -4096;							\
+  bgtu a0, a7, .Lsyscall_error ## name;
+
+# undef PSEUDO_END
+# define PSEUDO_END(sym) 					\
+  SYSCALL_ERROR_HANDLER (sym)					\
+  ret;								\
+  END (sym)
+
+# if !IS_IN_libc
+#  if defined (__PIC__)
+#   define SYSCALL_ERROR_HANDLER(name)				\
+.Lsyscall_error ## name:					\
+        la.tls.ie t1, errno;					\
+	add t1, t1, tp;						\
+	neg a0, a0;						\
+	sw a0, 0(t1);						\
+        li a0, -1;
+#  else
+#   define SYSCALL_ERROR_HANDLER(name)				\
+.Lsyscall_error ## name:					\
+        lui t1, %tprel_hi(errno);				\
+        add t1, t1, tp, %tprel_add(errno);			\
+	neg a0, a0;						\
+        sw a0, %tprel_lo(errno)(t1);				\
+        li a0, -1;
+#  endif
+# else
+#  define SYSCALL_ERROR_HANDLER(name)				\
+.Lsyscall_error ## name:					\
+        j       __syscall_error;
+# endif
+
+/* Performs a system call, not setting errno.  */
+# undef PSEUDO_NEORRNO
+# define PSEUDO_NOERRNO(name, syscall_name, args)	\
+  .align 2;						\
+  ENTRY (name);						\
+  li a7, SYS_ify (syscall_name);			\
+  scall;
+
+# undef PSEUDO_END_NOERRNO
+# define PSEUDO_END_NOERRNO(name)			\
+  END (name)
+
+# undef ret_NOERRNO
+# define ret_NOERRNO ret
+
+/* Perfroms a system call, returning the error code.  */
+# undef PSEUDO_ERRVAL
+# define PSEUDO_ERRVAL(name, syscall_name, args) 	\
+  PSEUDO_NOERRNO (name, syscall_name, args)		\
+  neg a0, a0;
+
+# undef PSEUDO_END_ERRVAL
+# define PSEUDO_END_ERRVAL(name)			\
+  END (name)
+
+# undef ret_ERRVAL
+# define ret_ERRVAL ret
+
+#endif /* __ASSEMBLER__ */
+
+/* In order to get __set_errno() definition in INLINE_SYSCALL.  */
+#ifndef __ASSEMBLER__
+# include <errno.h>
+#endif
+
+#undef SYS_ify
+#define SYS_ify(syscall_name)	__NR_##syscall_name
+
+#ifndef __ASSEMBLER__
+
+/* List of system calls which are supported as vsyscalls.  */
+# define HAVE_CLOCK_GETRES_VSYSCALL	1
+# define HAVE_CLOCK_GETTIME_VSYSCALL	1
+# define HAVE_GETTIMEOFDAY_VSYSCALL	1
+# define HAVE_GETCPU_VSYSCALL		1
+
+
+extern long int __syscall_error (long int neg_errno);
+
+#endif /* ! __ASSEMBLER__ */
+
+#endif /* linux/riscv/sysdep.h */