arch: ppc: new port

README.md

@@ -17,3 +17,4 @@ Right now these archs are supported:
  * x86_64
  * armv6+ (`arm`)
  * aarch64
+ * ppc

arch/ppc/defs.h

@@ -0,0 +1,62 @@
+#ifndef __ARCH_PPC_DEFS_H
+#define __ARCH_PPC_DEFS_H
+
+#define REG_R0		(0)
+#define REG_R1		(1)
+#define REG_R2		(2)
+#define REG_R3		(3)
+#define REG_R4		(4)
+#define REG_R5		(5)
+#define REG_R6		(6)
+#define REG_R7		(7)
+#define REG_R8		(8)
+#define REG_R9		(9)
+#define REG_R10		(10)
+#define REG_R11		(11)
+#define REG_R12		(12)
+#define REG_R13		(13)
+#define REG_R14		(14)
+#define REG_R15		(15)
+#define REG_R16		(16)
+#define REG_R17		(17)
+#define REG_R18		(18)
+#define REG_R19		(19)
+#define REG_R20		(20)
+#define REG_R21		(21)
+#define REG_R22		(22)
+#define REG_R23		(23)
+#define REG_R24		(24)
+#define REG_R25		(25)
+#define REG_R26		(26)
+#define REG_R27		(27)
+#define REG_R28		(28)
+#define REG_R29		(29)
+#define REG_R30		(30)
+#define REG_R31		(31)
+#define REG_R32		(32)
+#define REG_R33		(33)
+#define REG_R34		(34)
+#define REG_R35		(35)
+#define REG_R36		(36)
+#define REG_R37		(37)
+#define REG_R38		(38)
+#define REG_R39		(39)
+#define REG_R40		(40)
+#define REG_R41		(41)
+#define REG_R42		(42)
+#define REG_R43		(43)
+#define REG_R44		(44)
+#define REG_R45		(45)
+#define REG_R46		(46)
+#define REG_R47		(47)
+
+/* sp register is actually %r1 */
+#define REG_SP		REG_R1
+
+/* nip register is actually %srr0 (r32) */
+#define REG_NIP		REG_R32
+
+/* lnk register is actually r32 */
+#define REG_LNK		REG_R36
+
+#endif

arch/ppc/getcontext.c

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2018 William Pitcock <nenolod@dereferenced.org>
+ *
+ * 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 <stddef.h>
+#include <stdarg.h>
+#include <signal.h>
+#include <string.h>
+#include <stdint.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+
+
+int
+__getcontext(ucontext_t *ucp)
+{
+#ifdef SYS_swapcontext
+	int r;
+
+	r = syscall(SYS_swapcontext, ucp, NULL, sizeof(ucontext_t));
+	if (r < 0)
+	{
+		errno = -r;
+		return -1;
+	}
+
+	return 0;
+#else
+	errno = ENOSYS;
+	return -1;
+#endif
+}
+
+
+extern __typeof(__getcontext) getcontext __attribute__((weak, __alias__("__getcontext")));

arch/ppc/makecontext.c

@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2018 William Pitcock <nenolod@dereferenced.org>
+ *
+ * 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 <stddef.h>
+#include <stdarg.h>
+#include <signal.h>
+#include <string.h>
+#include <stdint.h>
+
+
+#include "defs.h"
+
+
+extern void __start_context(void);
+
+
+void
+__makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...)
+{
+	greg_t *sp, *argp;
+	va_list va;
+	int i;
+	unsigned int uc_link, stack_args;
+
+	stack_args = argc > 8 ? argc - 8 : 0;
+	uc_link = stack_args + 1;
+
+	sp = (greg_t *) ((uintptr_t) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
+	sp -= (uc_link + 1);
+	sp = (greg_t *) (((uintptr_t) sp & -16L) - 8);
+
+	ucp->uc_mcontext.gregs[REG_NIP]  = (uintptr_t) func;
+	ucp->uc_mcontext.gregs[REG_LNK]  = (uintptr_t) &__start_context;
+	ucp->uc_mcontext.gregs[REG_R31]  = (uintptr_t) ucp->uc_link;
+	ucp->uc_mcontext.gregs[REG_SP]   = (uintptr_t) sp;
+
+	sp[0] = (uintptr_t) &__start_context;
+	sp[uc_link] = (uintptr_t) ucp->uc_link;
+	argp = &sp[2];
+
+	va_start(va, argc);
+
+	for (i = 0; i < argc; i++)
+		switch (i)
+		{
+		case 0:
+		case 1:
+		case 2:
+		case 3:
+		case 4:
+		case 5:
+		case 6:
+		case 7:
+			ucp->uc_mcontext.gregs[i + 3] = va_arg (va, greg_t);
+			break;
+		default:
+			*argp++ = va_arg (va, greg_t);
+			break;
+		}
+
+	va_end(va);
+}
+
+
+extern __typeof(__makecontext) makecontext __attribute__((weak, __alias__("__makecontext")));

arch/ppc/setcontext.c

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2018 William Pitcock <nenolod@dereferenced.org>
+ *
+ * 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 <stddef.h>
+#include <stdarg.h>
+#include <signal.h>
+#include <string.h>
+#include <stdint.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+
+
+int
+__setcontext(const ucontext_t *ucp)
+{
+#ifdef SYS_swapcontext
+	int r;
+
+	r = syscall(SYS_swapcontext, NULL, (void *) ucp, sizeof(ucontext_t));
+	if (r < 0)
+	{
+		errno = -r;
+		return -1;
+	}
+
+	return r;
+#else
+	errno = ENOSYS;
+	return -1;
+#endif
+}
+
+
+extern __typeof(__setcontext) setcontext __attribute__((weak, __alias__("__setcontext")));

arch/ppc/startcontext.S

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2018 William Pitcock <nenolod@dereferenced.org>
+ *
+ * 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.
+ */
+
+.globl __start_context;
+__start_context:
+	/* get the proper context into position and test for NULL */
+	mr.	3,31
+	beq	hosed
+	bl	__setcontext@local
+
+hosed:
+	b	exit@GOT

arch/ppc/swapcontext.c

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2018 William Pitcock <nenolod@dereferenced.org>
+ *
+ * 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 <stddef.h>
+#include <stdarg.h>
+#include <signal.h>
+#include <string.h>
+#include <stdint.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+
+
+int
+__swapcontext(ucontext_t *oucp, const ucontext_t *ucp)
+{
+#ifdef SYS_swapcontext
+	int r;
+
+	r = syscall(SYS_swapcontext, oucp, ucp, sizeof(ucontext_t));
+	if (r < 0)
+	{
+		errno = -r;
+		return -1;
+	}
+
+	return r;
+#else
+	errno = ENOSYS;
+	return -1;
+#endif
+}
+
+
+extern __typeof(__swapcontext) swapcontext __attribute__((weak, __alias__("__swapcontext")));