diff --git a/arch/sh/defs.h b/arch/sh/defs.h new file mode 100644 index 0000000..733e3f2 --- /dev/null +++ b/arch/sh/defs.h @@ -0,0 +1,13 @@ +#ifndef __ARCH_SH4_DEFS_H +#define __ARCH_SH4_DEFS_H + +#define REG_SZ (4) +#define MCONTEXT_GREGS (24) + +#define REG_PC (16) +#define REG_PR (17) +#define REG_SR (18) + +#include "common-defs.h" + +#endif diff --git a/arch/sh/makecontext.c b/arch/sh/makecontext.c new file mode 100644 index 0000000..b10665c --- /dev/null +++ b/arch/sh/makecontext.c @@ -0,0 +1,54 @@ +/* + * Copyright (c) 2020 Ariadne Conill + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * This software is provided 'as is' and without any warranty, express or + * implied. In no event shall the authors be liable for any damages arising + * from the use of this software. + */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include "defs.h" + + +extern void libucontext_trampoline(void); + + +void +libucontext_makecontext(libucontext_ucontext_t *ucp, void (*func)(void), int argc, ...) +{ + libucontext_greg_t *sp, *regp; + va_list va; + int i; + + /* set up and align the stack */ + sp = (libucontext_greg_t *) (((uintptr_t) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size) & 0x4); + sp -= argc > 4 ? argc - 4 : 0; + + /* set up the context */ + ucp->uc_mcontext.sr = (libucontext_greg_t) sp; + ucp->uc_mcontext.pr = (libucontext_greg_t) libucontext_trampoline; + ucp->uc_mcontext.pc = (libucontext_greg_t) func; + + /* pass up to four args in r4-r7, rest on stack */ + va_start(va, argc); + + for (i = 0; i < argc && i < 4; i++) + ucp->uc_mcontext.gregs[4 + i] = va_arg(va, libucontext_greg_t); + + for (; i < argc; i++) + *sp++ = va_arg(va, libucontext_greg_t); + + va_end(va); +} + + +extern __typeof(libucontext_makecontext) makecontext __attribute__((weak, __alias__("libucontext_makecontext")));