arch-sh.h

  1/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
  2/*
  3 * SuperH specific definitions for NOLIBC
  4 * Copyright (C) 2025 Thomas Weißschuh <linux@weissschuh.net>
  5 */
  6
  7#ifndef _NOLIBC_ARCH_SH_H
  8#define _NOLIBC_ARCH_SH_H
  9
 10#include "compiler.h"
 11#include "crt.h"
 12
 13/*
 14 * Syscalls for SuperH:
 15 *   - registers are 32bit wide
 16 *   - syscall number is passed in r3
 17 *   - arguments are in r4, r5, r6, r7, r0, r1, r2
 18 *   - the system call is performed by calling trapa #31
 19 *   - syscall return value is in r0
 20 */
 21
 22#define my_syscall0(num)                                                      \
 23({                                                                            \
 24	register long _num __asm__ ("r3") = (num);                            \
 25	register long _ret __asm__ ("r0");                                    \
 26									      \
 27	__asm__ volatile (                                                    \
 28		"trapa #31"                                                   \
 29		: "=r"(_ret)                                                  \
 30		: "r"(_num)                                                   \
 31		: "memory", "cc"                                              \
 32	);                                                                    \
 33	_ret;                                                                 \
 34})
 35
 36#define my_syscall1(num, arg1)                                                \
 37({                                                                            \
 38	register long _num __asm__ ("r3") = (num);                            \
 39	register long _ret __asm__ ("r0");                                    \
 40	register long _arg1 __asm__ ("r4") = (long)(arg1);                    \
 41									      \
 42	__asm__ volatile (                                                    \
 43		"trapa #31"                                                   \
 44		: "=r"(_ret)                                                  \
 45		: "r"(_num), "r"(_arg1)                                       \
 46		: "memory", "cc"                                              \
 47	);                                                                    \
 48	_ret;                                                                 \
 49})
 50
 51#define my_syscall2(num, arg1, arg2)                                          \
 52({                                                                            \
 53	register long _num __asm__ ("r3") = (num);                            \
 54	register long _ret __asm__ ("r0");                                    \
 55	register long _arg1 __asm__ ("r4") = (long)(arg1);                    \
 56	register long _arg2 __asm__ ("r5") = (long)(arg2);                    \
 57									      \
 58	__asm__ volatile (                                                    \
 59		"trapa #31"                                                   \
 60		: "=r"(_ret)                                                  \
 61		: "r"(_num), "r"(_arg1), "r"(_arg2)                           \
 62		: "memory", "cc"                                              \
 63	);                                                                    \
 64	_ret;                                                                 \
 65})
 66
 67#define my_syscall3(num, arg1, arg2, arg3)                                    \
 68({                                                                            \
 69	register long _num __asm__ ("r3") = (num);                            \
 70	register long _ret __asm__ ("r0");                                    \
 71	register long _arg1 __asm__ ("r4") = (long)(arg1);                    \
 72	register long _arg2 __asm__ ("r5") = (long)(arg2);                    \
 73	register long _arg3 __asm__ ("r6") = (long)(arg3);                    \
 74									      \
 75	__asm__ volatile (                                                    \
 76		"trapa #31"                                                   \
 77		: "=r"(_ret)                                                  \
 78		: "r"(_num), "r"(_arg1), "r"(_arg2), "r"(_arg3)               \
 79		: "memory", "cc"                                              \
 80	);                                                                    \
 81	_ret;                                                                 \
 82})
 83
 84#define my_syscall4(num, arg1, arg2, arg3, arg4)                              \
 85({                                                                            \
 86	register long _num __asm__ ("r3") = (num);                            \
 87	register long _ret __asm__ ("r0");                                    \
 88	register long _arg1 __asm__ ("r4") = (long)(arg1);                    \
 89	register long _arg2 __asm__ ("r5") = (long)(arg2);                    \
 90	register long _arg3 __asm__ ("r6") = (long)(arg3);                    \
 91	register long _arg4 __asm__ ("r7") = (long)(arg4);                    \
 92									      \
 93	__asm__ volatile (                                                    \
 94		"trapa #31"                                                   \
 95		: "=r"(_ret)                                                  \
 96		: "r"(_num), "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4)   \
 97		: "memory", "cc"                                              \
 98	);                                                                    \
 99	_ret;                                                                 \
100})
101
102#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5)                        \
103({                                                                            \
104	register long _num __asm__ ("r3") = (num);                            \
105	register long _ret __asm__ ("r0");                                    \
106	register long _arg1 __asm__ ("r4") = (long)(arg1);                    \
107	register long _arg2 __asm__ ("r5") = (long)(arg2);                    \
108	register long _arg3 __asm__ ("r6") = (long)(arg3);                    \
109	register long _arg4 __asm__ ("r7") = (long)(arg4);                    \
110	register long _arg5 __asm__ ("r0") = (long)(arg5);                    \
111									      \
112	__asm__ volatile (                                                    \
113		"trapa #31"                                                   \
114		: "=r"(_ret)                                                  \
115		: "r"(_num), "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4),  \
116		  "r"(_arg5)                                                  \
117		: "memory", "cc"                                              \
118	);                                                                    \
119	_ret;                                                                 \
120})
121
122#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6)                  \
123({                                                                            \
124	register long _num __asm__ ("r3") = (num);                            \
125	register long _ret __asm__ ("r0");                                    \
126	register long _arg1 __asm__ ("r4") = (long)(arg1);                    \
127	register long _arg2 __asm__ ("r5") = (long)(arg2);                    \
128	register long _arg3 __asm__ ("r6") = (long)(arg3);                    \
129	register long _arg4 __asm__ ("r7") = (long)(arg4);                    \
130	register long _arg5 __asm__ ("r0") = (long)(arg5);                    \
131	register long _arg6 __asm__ ("r1") = (long)(arg6);                    \
132									      \
133	__asm__ volatile (                                                    \
134		"trapa #31"                                                   \
135		: "=r"(_ret)                                                  \
136		: "r"(_num), "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4),  \
137		  "r"(_arg5), "r"(_arg6)                                      \
138		: "memory", "cc"                                              \
139	);                                                                    \
140	_ret;                                                                 \
141})
142
143#ifndef NOLIBC_NO_RUNTIME
144/* startup code */
145void _start_wrapper(void);
146void __attribute__((weak,noreturn)) __nolibc_entrypoint __no_stack_protector _start_wrapper(void)
147{
148	__asm__ volatile (
149		".global _start\n"           /* The C function will have a prologue,         */
150		".type _start, @function\n"  /* corrupting "sp"                              */
151		".weak _start\n"
152		"_start:\n"
153
154		"mov sp, r4\n"               /* save argc pointer to r4, as arg1 of _start_c */
155		"bsr _start_c\n"             /* transfer to c runtime                        */
156		"nop\n"                      /* delay slot                                   */
157
158		".size _start, .-_start\n"
159	);
160	__nolibc_entrypoint_epilogue();
161}
162#endif /* NOLIBC_NO_RUNTIME */
163
164#endif /* _NOLIBC_ARCH_SH_H */