Commit a preview of osx386 and osxppc as new platforms.

These produce Mach-o executables for Mac OS X on Intel or PowerPC
processors.  Our code generator for PowerPC (mach/powerpc) still has
bugs.  Some examples seem to run, but startrek crashes.  Our code
generator for Intel (mach/i386) is better.

There is a problem with job control.  If you run paranoia or startrek,
then suspend the job (^Z) and resume it ('fg' in bash), then read(2)
might fail with EINTR.

The larger files in this commit are
 - plat/osx/cvmach/cvmach.c
 - plat/osx/libsys/brk.c
 - plat/osx386/libsys/sigaction.s
 - plat/osxppc/libsys/sigaction.s

build.lua

@@ -9,6 +9,8 @@ vars.plats = {
 	"linux386",
 	"linux68k",
 	"linuxppc",
+	"osx386",
+	"osxppc",
 	"pc86",
 	"rpi",
 }

plat/osx/cvmach/build.lua

@@ -0,0 +1,17 @@
+cprogram {
+	name = "cvmach",
+	srcs = { "./cvmach.c" },
+	deps = {
+		"h+emheaders",
+		-- Next line only because object.h includes ansi.h
+		"modules+headers",
+		"modules/src/object+lib",
+	}
+}
+
+installable {
+	name = "pkg",
+	map = {
+		["$(PLATDEP)/cvmach"] = "+cvmach",
+	}
+}

plat/osx/cvmach/cvmach.c

@@ -0,0 +1,418 @@
+/*
+ * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
+ * See the copyright notice in the ACK home directory, in the file "Copyright".
+ */
+
+/*
+ * cvmach.c - convert ack.out to mach-o
+ *
+ * Mostly pinched from aelflod (util/amisc/aelflod.c), which pinched
+ * from the ARM cv (mach/arm/cv/cv.c), which pinched from the m68k2 cv
+ * (mach/m68k2/cv/cv.c).  The code to read ack.out format using
+ * liboject is pinched from the Xenix i386 cv (mach/i386/cv/cv.c).
+ */
+
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <out.h>
+/* Can't find #include <object.h>*/
+
+/* Header and section table of ack.out */
+struct outhead	outhead;
+struct outsect	outsect[S_MAX];
+
+int bigendian;			/* Emit big-endian Mach-o? */
+int cpu_type;
+uint32_t entry;			/* Virtual address of entry point */
+uint32_t sz_thread_command;
+
+char *outputfile = NULL;	/* Name of output file, or NULL */
+char *program;			/* Name of current program: argv[0] */
+FILE *output;			/* Output stream */
+#define writef(a, b, c)	fwrite((a), (b), (c), output)
+
+/* Segment numbers in ack.out */
+enum {
+	TEXT = 0,
+	ROM,
+	DATA,
+	BSS,
+	NUM_SEGMENTS
+};
+
+/* Constants from Mach headers */
+#define MH_MAGIC			0xfeedface
+#define MH_EXECUTE			2
+#define LC_SEGMENT			1
+#define LC_UNIXTHREAD			5
+
+#define CPU_TYPE_X86			7
+#define CPU_SUBTYPE_X86_ALL		3
+#define x86_THREAD_STATE32		1
+#define x86_THREAD_STATE32_COUNT	16
+
+#define CPU_TYPE_POWERPC		18
+#define CPU_SUBTYPE_POWERPC_ALL		0
+#define PPC_THREAD_STATE		1
+#define PPC_THREAD_STATE_COUNT		40
+
+#define VM_PROT_NONE			0x0
+#define VM_PROT_READ			0x1
+#define VM_PROT_WRITE			0x2
+#define VM_PROT_EXECUTE			0x4
+
+/* sizes of Mach structs */
+#define SZ_MACH_HEADER			28
+#define SZ_SEGMENT_COMMAND		56
+#define SZ_THREAD_COMMAND_BF_STATE	16
+
+/* the page size for x86 and PowerPC */
+#define CV_PGSZ				4096
+/* u modulo page size */
+#define pg_mod(u) ((u) & (CV_PGSZ - 1))
+/* u rounded down to whole pages */
+#define pg_trunc(u) ((u) & ~(CV_PGSZ - 1))
+
+
+void usage(void)
+{
+	fprintf(stderr, "Usage: %s -m<num> <inputfile> <outputfile>\n",
+	    program);
+	exit(1);
+}
+
+/* Produce an error message and exit. */
+void fatal(const char* s, ...)
+{
+	va_list ap;
+
+	fprintf(stderr, "%s: ",program) ;
+
+	va_start(ap, s);
+	vfprintf(stderr, s, ap);
+	va_end(ap);
+
+	fprintf(stderr, "\n");
+
+	if (outputfile)
+		unlink(outputfile);
+	exit(1);
+}
+
+void rd_fatal(void)
+{
+	fatal("read error");
+}
+
+/* Calculate the result of a aligned to b (rounding up if necessary).
+ * b must be a power of two. */
+uint32_t align(uint32_t a, uint32_t b)
+{
+	a += b - 1;
+	return a & ~(b-1);
+}
+ 
+
+/* Writes out a 32-bit value in the appropriate endianness. */
+void emit32(uint32_t value)
+{
+	unsigned char buffer[4];
+	
+	if (bigendian)
+	{
+		buffer[0] = (value >> 24) & 0xFF;
+		buffer[1] = (value >> 16) & 0xFF;
+		buffer[2] = (value >>  8) & 0xFF;
+		buffer[3] = (value >>  0) & 0xFF;
+	}
+	else
+	{
+		buffer[3] = (value >> 24) & 0xFF;
+		buffer[2] = (value >> 16) & 0xFF;
+		buffer[1] = (value >>  8) & 0xFF;
+		buffer[0] = (value >>  0) & 0xFF;
+	}
+	
+	writef(buffer, 1, sizeof(buffer));
+}
+
+/* Copies the contents of a section from the input stream
+ * to the output stream. */
+void emit_section(int section_nr)
+{
+	struct outsect *section = &outsect[section_nr];
+	size_t blocksize;
+	uint32_t n = section->os_flen;
+	char buffer[BUFSIZ];
+
+	rd_outsect(section_nr);
+	while (n > 0)
+	{
+		blocksize = (n > BUFSIZ) ? BUFSIZ : n;
+		rd_emit(buffer, (long)blocksize);
+		writef(buffer, 1, blocksize);
+		n -= blocksize;
+	}
+
+	/* Zero fill any remaining space. */
+	n = section->os_size - section->os_flen;
+	if (n > 0)
+	{
+		memset(buffer, 0, BUFSIZ);
+		while (n > 0)
+		{
+			blocksize = (n > BUFSIZ) ? BUFSIZ : n;
+			writef(buffer, 1, blocksize);
+			n -= blocksize;
+		}
+	}
+}
+
+void emit_lc_segment(char *name, uint32_t vm_ad, uint32_t vm_sz,
+    uint32_t f_off, uint32_t f_sz, int prot)
+{
+	char namebuf[16];
+	int flags, maxprot;
+	
+	if (prot == VM_PROT_NONE) {
+		/* special values for __PAGEZERO */
+		maxprot = VM_PROT_NONE;
+		flags = 4; /* NORELOC */
+	} else {
+		maxprot = VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE;
+		flags = 0;
+	}
+
+	/* Use strncpy() to pad namebuf with '\0' bytes. */
+	strncpy(namebuf, name, sizeof(namebuf));
+
+	emit32(LC_SEGMENT);		/* command */
+	emit32(SZ_SEGMENT_COMMAND);	/* size of command */
+	writef(namebuf, 1, sizeof(namebuf));
+	emit32(vm_ad);			/* vm address */
+	emit32(vm_sz);			/* vm size */
+	emit32(f_off);			/* file offset */
+	emit32(f_sz);			/* file size */
+	emit32(maxprot);		/* max protection */
+	emit32(prot);			/* initial protection */
+	emit32(0);			/* number of Mach sections */
+	emit32(flags);			/* flags */
+}
+
+void emit_lc_unixthread(void)
+{
+	int i, ireg, ts, ts_count;
+
+	/*
+	 * The thread state has ts_count registers.  The ireg'th
+	 * register holds the entry point.  We can set other registers
+	 * to zero.  At execution time, the kernel will allocate a
+	 * stack and set the stack pointer.
+	 */
+	switch (cpu_type) {
+	case CPU_TYPE_X86:
+		ireg = 10;	/* eip */
+		ts = x86_THREAD_STATE32;
+		ts_count = x86_THREAD_STATE32_COUNT;
+		break;
+	case CPU_TYPE_POWERPC:
+		ireg = 0;	/* srr0 */
+		ts = PPC_THREAD_STATE;
+		ts_count = PPC_THREAD_STATE_COUNT;
+		break;
+	}
+
+	emit32(LC_UNIXTHREAD);		/* command */
+	emit32(sz_thread_command);	/* size of command */
+	emit32(ts);			/* thread state */
+	emit32(ts_count);		/* thread state count */
+	for (i = 0; i < ts_count; i++) {
+		if (i == ireg)
+			emit32(entry);
+		else
+			emit32(0);
+	}
+}
+
+
+int main(int argc, char *argv[])
+{
+	uint32_t len2, len3, mach_base, pad, sz_bf_entry, sz_load_cmds;
+	int cpu_subtype, mflag = 0;
+
+	/* General housecleaning and setup. */
+	output = stdout;
+	program = argv[0];
+	
+	/* Read in and process any flags. */
+	while ((argc > 1) && (argv[1][0] == '-')) {
+		switch (argv[1][1]) {
+		case 'm': /* machine cpu type */
+			mflag = 1;
+			cpu_type = atoi(&argv[1][2]);
+			break;
+		case 'h': /* help */
+		default:
+			usage();
+		}
+
+		argv++;
+		argc--;
+	}
+
+	if (!mflag)
+		usage();
+
+	/* Check cpu type. */
+	switch (cpu_type) {
+	case CPU_TYPE_X86:
+		bigendian = 0;
+		cpu_subtype = CPU_SUBTYPE_X86_ALL;
+		sz_thread_command = 4 * x86_THREAD_STATE32_COUNT;
+		break;
+	case CPU_TYPE_POWERPC:
+		bigendian = 1;
+		cpu_subtype = CPU_SUBTYPE_POWERPC_ALL;
+		sz_thread_command = 4 * PPC_THREAD_STATE_COUNT;
+		break;
+	default:
+		/* Can't emit LC_UNIXTHREAD for unknown cpu. */
+		fatal("unknown cpu type -m%d", cpu_type);
+	}
+	sz_thread_command += SZ_THREAD_COMMAND_BF_STATE;
+
+	/* Process the rest of the arguments. */
+	switch (argc) {
+	case 1: /* No parameters --- read from stdin, write to stdout. */
+		rd_fdopen(0);
+		break;
+
+	case 3: /* Both input and output files specified. */
+		output = fopen(argv[2], "w");
+		if (!output)
+			fatal("unable to open output file.");
+		outputfile = argv[2];
+		/* FALLTHROUGH */
+
+	case 2: /* Input file specified. */
+		if (! rd_open(argv[1]))
+			fatal("unable to open input file.");
+		break;
+
+	default:
+		usage();
+	}
+
+	rd_ohead(&outhead);
+	if (BADMAGIC(outhead))
+		fatal("Not an ack object file.");
+	if (outhead.oh_flags & HF_LINK)
+		fatal("Contains unresolved references.");
+	if (outhead.oh_nrelo > 0)
+		fprintf(stderr, "Warning: relocation information present.");
+	if (outhead.oh_nsect != NUM_SEGMENTS &&
+	    outhead.oh_nsect != NUM_SEGMENTS + 1 ) {
+		fatal("Input file must have %d sections, not %ld\n",
+		    NUM_SEGMENTS, (long)outhead.oh_nsect);
+	}
+
+	rd_sect(outsect, outhead.oh_nsect);
+
+	/*
+	 * 1st Mach segment: __PAGEZERO
+	 * 2nd Mach segment: __TEXT
+	 *   Mach headers and load commands
+	 *   ack TEXT
+	 *   ack ROM
+	 * 3rd Mach segment: __DATA
+	 *   ack DATA
+	 *   ack BSS
+	 */
+
+	/* Find entry point and check that TEXT begins there. */
+	mach_base = pg_trunc(outsect[TEXT].os_base);
+	sz_load_cmds = 3 * SZ_SEGMENT_COMMAND + sz_thread_command;
+	sz_bf_entry = SZ_MACH_HEADER + sz_load_cmds;
+	entry = mach_base + sz_bf_entry;
+	if (entry != outsect[TEXT].os_base) {
+		fatal("text segment must have base 0x%lx, not 0x%lx\n",
+		    entry, outsect[TEXT].os_base);
+	}
+
+	/* Check that ROM can follow TEXT in 2nd Mach segment. */
+	outsect[TEXT].os_size =
+	    align(outsect[TEXT].os_size, outsect[ROM].os_lign);
+	if (outsect[ROM].os_base !=
+	    outsect[TEXT].os_base + outsect[TEXT].os_size)
+		fatal("the rom segment must follow the text segment.");
+
+	/*
+	 * Insert padding between ROM and DATA, such that
+	 *   pg_mod(len2) == pg_mod(outsect[DATA].os_base)
+	 *
+	 * This will allow us to map the 3rd Mach segment at the
+	 * beginning of a page, such that DATA is at its base.
+	 */
+	len2 = sz_bf_entry + outsect[TEXT].os_size + outsect[ROM].os_size;
+	pad = pg_mod(outsect[DATA].os_base - len2);
+	outsect[ROM].os_size += pad;
+	len2 = pg_trunc(len2 + pad);
+
+	/* Check that BSS can follow DATA in 3rd Mach segment. */
+	if (outsect[BSS].os_flen != 0)
+		fatal("the bss space contains initialized data.");
+	if (outsect[BSS].os_base <
+	    outsect[DATA].os_base + outsect[DATA].os_size)
+		fatal("the bss segment must follow the data segment.");
+
+	len3 = outsect[BSS].os_base - pg_trunc(outsect[DATA].os_base) +
+	    outsect[BSS].os_size;
+
+	if (outhead.oh_nsect == NUM_SEGMENTS + 1) {
+		if (outsect[NUM_SEGMENTS].os_base !=
+		    outsect[BSS].os_base + outsect[BSS].os_size)
+			fatal("end segment must follow bss");
+		if (outsect[NUM_SEGMENTS].os_size != 0)
+			fatal("end segment must be empty");
+	}
+
+	/* Emit the Mach header. */
+	emit32(MH_MAGIC);	/* magic */
+	emit32(cpu_type);	/* cpu type */
+	emit32(cpu_subtype);	/* cpu subtype */
+	emit32(MH_EXECUTE);	/* file type */
+	emit32(4);		/* number of load commands */
+	emit32(sz_load_cmds);	/* size of load commands */
+	emit32(0);		/* flags */
+
+	/*			vm address:	vm size:
+	 * 1st Mach segment:	NULL		CV_PGSZ
+	 * 2nd Mach segment:	mach_base	len2
+	 * 3rd Mach segment:	mach_base+len2	len3
+	 *
+	 *			file offset:	file size:
+	 * 2nd Mach segment:	0		len2
+	 * 3rd Mach segment:	len2		DATA os_size
+	 */
+	emit_lc_segment("__PAGEZERO", 0 /* NULL */, CV_PGSZ,
+	    0, 0, VM_PROT_NONE);
+	emit_lc_segment("__TEXT", mach_base, len2,
+	    0, len2, VM_PROT_READ | VM_PROT_EXECUTE);
+	emit_lc_segment("__DATA", mach_base + len2, len3,
+	    len2, outsect[DATA].os_size, VM_PROT_READ | VM_PROT_WRITE);
+	emit_lc_unixthread();
+
+	/* Emit non-empty sections. */
+	emit_section(TEXT);
+	emit_section(ROM);
+	emit_section(DATA);
+
+	if (ferror(output))
+		fatal("write error");
+
+	return 0;
+}

plat/osx/include/ack/config.h

@@ -0,0 +1,14 @@
+/* $Source$
+ * $State$
+ * $Revision$
+ */
+
+#ifndef _ACK_CONFIG_H
+#define _ACK_CONFIG_H
+
+/* We're providing a time() system call rather than wanting a wrapper around
+ * gettimeofday() in the libc. */
+ 
+/* #define ACKCONF_TIME_IS_A_SYSCALL */
+
+#endif

plat/osx/include/sys/mman.h

@@ -0,0 +1,20 @@
+#ifndef _SYS_MMAN_H
+#define _SYS_MMAN_H
+
+#include <sys/types.h>
+
+#define MAP_FAILED ((void *)-1)
+
+#define PROT_NONE	0x00
+#define PROT_READ	0x01
+#define PROT_WRITE	0x02
+#define PROT_EXEC	0x04
+
+#define MAP_PRIVATE	0x0002
+#define MAP_FIXED	0x0010
+#define MAP_ANON	0x1000
+
+void *mmap(void *, size_t, int, int, int, off_t);
+int mprotect(void *, size_t, int);
+
+#endif

plat/osx/include/sys/types.h

@@ -0,0 +1,9 @@
+#ifndef _SYS_TYPES_H
+#define _SYS_TYPES_H
+
+#include <stddef.h> /* for off_t, ptrdiff_t, size_t */
+
+typedef int pid_t;
+typedef ptrdiff_t ssize_t;
+
+#endif

plat/osx/include/unistd.h

@@ -0,0 +1,132 @@
+#ifndef _UNISTD_H
+#define _UNISTD_H
+
+#include <sys/types.h>
+
+/*
+ * XXX - The following parts belong in other header files,
+ * but those headers are including us!
+ */
+
+/* XXX - begin sys/ioctl.h */
+
+#define TIOCGETD	0x4004741a
+
+int ioctl(int, unsigned long, ...);
+
+/* XXX - end sys/ioctl.h */
+
+/* XXX - begin sys/time.h */
+
+/* Don't conflict with time_t from <time.h> */
+typedef long _libsys_time_t;
+typedef int suseconds_t;
+
+struct timeval {
+	_libsys_time_t tv_sec;
+	suseconds_t tv_usec;
+};
+
+struct timezone {
+	int tz_minuteswest;
+	int tz_dsttime;
+};
+
+int gettimeofday(struct timeval *, struct timezone *);
+
+/* XXX - end sys/time.h */
+
+/* XXX - begin fcntl.h */
+
+/* flags for open() */
+#define O_RDONLY	0x0000
+#define O_WRONLY	0x0001
+#define O_RDWR		0x0002
+#define O_NONBLOCK	0x0004
+#define O_APPEND	0x0008
+#define O_CREAT		0x0200
+#define O_TRUNC		0x0400
+#define O_EXCL		0x0800
+
+typedef int mode_t;
+
+int creat(const char *, mode_t);
+int open(const char *, int, ...);
+
+/* XXX - end fcntl.h */
+
+/* XXX - begin signal.h */
+
+#define SIGHUP		1
+#define SIGINT		2
+#define SIGQUIT		3
+#define SIGILL		4
+#define SIGTRAP		5
+#define SIGABRT		6
+#define SIGEMT		7
+#define SIGFPE		8
+#define SIGKILL		9
+#define SIGBUS		10
+#define SIGSEGV		11
+#define SIGSYS		12
+#define SIGPIPE		13
+#define SIGALRM		14
+#define SIGTERM		15
+#define SIGURG		16
+#define SIGSTOP		17
+#define SIGTSTP		18
+#define SIGCONT		19
+#define SIGCHLD		20
+#define SIGTTIN		21
+#define SIGTTOU		22
+#define SIGIO		23
+#define SIGXCPU		24
+#define SIGXFSZ		25
+#define SIGVTALRM	26
+#define SIGPROF		27
+#define SIGWINCH	28
+#define SIGINFO		29
+#define SIGUSR1		30
+#define SIGUSR2		31
+#define _NSIG		32
+
+/* sa_flags */
+#define SA_RESTART	0x0002
+
+typedef void (*sig_t)(int);
+#define SIG_DFL ((sig_t)0)
+#define SIG_IGN ((sig_t)1)
+#define SIG_ERR ((sig_t)-1)
+
+typedef unsigned int sigset_t;
+
+struct __siginfo;
+
+struct sigaction {
+	union {
+		void (*__sa_handler)(int);
+		void (*__sa_sigaction)(int, struct __siginfo *, void *);
+	} __sigaction_u;
+	sigset_t sa_mask;
+	int sa_flags;
+};
+#define sa_handler __sigaction_u.__sa_handler
+#define sa_sigaction __sigaction_u.__sa_sigaction
+
+int kill(pid_t, int);
+int sigaction(int, const struct sigaction *, struct sigaction *);
+sig_t signal(int, sig_t);
+
+/* XXX - end signal.h */
+
+void _exit(int);
+int brk(void *);
+int close(int);
+pid_t getpid(void);
+int isatty(int);
+off_t lseek(int, off_t, int);
+ssize_t read(int, void *, size_t);
+void *sbrk(int);
+ssize_t write(int, const void *, size_t);
+
+#endif

plat/osx/libsys/brk.c

@@ -0,0 +1,95 @@
+/*
+ * This emulates brk() and sbrk() using mmap() and mprotect().
+ *
+ * We reserve exactly SEGMENTSZ bytes of address space by calling
+ * mmap() with PROT_NONE.  Then we allocate pages in our segment by
+ * calling mprotect() with PROT_READ|PROT_WRITE.
+ *
+ * This emulation can't resize its segment.  If SEGMENTSZ is too big,
+ * then programs might run out of address space for other mappings.
+ */
+#include <sys/mman.h>
+#include <errno.h>
+#include <unistd.h>
+
+/*
+ * PAGESZ must be correct for this system!
+ * SEGMENTSZ must be a multiple of PAGESZ.
+ */
+#define PAGESZ 0x1000		/* page size for i386, powerpc */
+#define SEGMENTSZ 0x20000000
+
+static char *segment;
+static char *cbreak;		/* current break */
+
+static void brk_init(void)
+{
+	/*
+	 * Try exactly once to reserve our segment.  If we fail, then
+	 * segment == MAP_FAILED and we never try again.
+	 */
+	if (segment == NULL) {
+		segment = mmap(NULL, SEGMENTSZ, PROT_NONE,
+		    MAP_PRIVATE|MAP_ANON, -1, 0);
+		cbreak = segment;
+	}
+}
+
+static int brk1(char *nbreak)
+{
+	size_t sz;
+	char *new, *old;
+
+	sz = (segment == MAP_FAILED) ? 0 : SEGMENTSZ;
+	if (nbreak < segment || nbreak > segment + sz) {
+		errno = ENOMEM;
+		return -1;
+	}
+
+	/* Round up to page size. */
+	old = (char *)(((size_t)cbreak + (PAGESZ-1)) & ~(PAGESZ-1));
+	new = (char *)(((size_t)nbreak + (PAGESZ-1)) & ~(PAGESZ-1));
+
+	if (new > old) {
+		/* Allocate pages by unprotecting them. */
+		if (mprotect(old, new - old, PROT_READ|PROT_WRITE) < 0) {
+			errno = ENOMEM;
+			return -1;
+		}
+	} else if (new < old) {
+		/*
+		 * Free pages by using MAP_FIXED to replace the
+		 * mapping.  Ignore errors.
+		 */
+		mmap(new, old - new, PROT_NONE,
+		    MAP_PRIVATE|MAP_ANON|MAP_FIXED, -1, 0);
+	}
+	cbreak = nbreak;
+	return 0;
+}
+
+int brk(void *addr)
+{
+	brk_init();
+	return brk1(addr);
+}
+
+void *sbrk(int incr)
+{
+	char *base, *nbreak;
+
+	brk_init();
+	base = cbreak;
+	nbreak = base + incr;
+
+	/* Did base + incr overflow? */
+	if ((incr < 0 && nbreak > base) ||
+	    (incr > 0 && nbreak < base)) {
+		errno = ENOMEM;
+		return (void*)-1;
+	}
+
+	if (brk1(nbreak) < 0)
+		return (void*)-1;
+	return base;
+}

plat/osx/libsys/creat.c

@@ -0,0 +1,6 @@
+#include <fcntl.h>
+
+int creat(const char *path, mode_t mode)
+{
+	open(path, O_CREAT | O_TRUNC | O_WRONLY, mode);
+}

plat/osx/libsys/isatty.c

@@ -0,0 +1,7 @@
+#include <sys/ioctl.h>
+
+int isatty(int fd)
+{
+	int line_disc;
+	return 0 <= ioctl(fd, TIOCGETD, &line_disc);
+}

plat/osx/libsys/signal.c

@@ -0,0 +1,16 @@
+#include <signal.h>
+
+sig_t signal(int sig, sig_t func)
+{
+	struct sigaction newsa, oldsa;
+	int i;
+
+	newsa.sa_handler = func;
+	newsa.sa_mask = 0; /* empty set */
+	newsa.sa_flags = SA_RESTART;
+
+	i = sigaction(sig, &newsa, &oldsa);
+	if (i < 0)
+		return SIG_ERR;
+	return oldsa.sa_handler;
+}

plat/osx386/boot.s

@@ -0,0 +1,69 @@
+! plat/osx386/boot.s
+
+! Declare segments (the order is important).
+
+.sect .text
+.sect .rom
+.sect .data
+.sect .bss
+
+.sect .text
+
+begtext:
+	! This code is placed at the entry point of the Mach-o
+	! executable and is the first thing that runs.
+	!
+	! On entry, the stack looks like this:
+	!
+	! sp+..            NULL
+	! sp+8+(4*argc)   env (X quads)
+	! sp+4+(4*argc)   NULL
+	! sp+4            argv (argc quads)
+	! sp              argc
+	!
+	! The ACK actually expects:
+	!
+	! sp+8            argc
+	! sp+4            argv
+	! sp              env
+	
+	mov eax, (esp)    ! eax = argc
+	lea ebx, 4(esp)   ! ebx = argv
+	lea ecx, (esp)(eax*4)
+	add ecx, 12       ! environ
+	
+	push ecx         ! environ
+	push ebx         ! argc
+	push eax         ! argv
+	push eax         ! dummy, representing the return argument
+	xor ebp, ebp
+	
+	jmp __m_a_i_n
+	
+	! This provides an emergency exit routine used by EM.
+	
+.define EXIT
+.extern EXIT
+EXIT:
+	push 1
+	jmp __exit
+	
+.sect rom
+begrom:
+
+.sect .data
+begdata:
+
+! Some magic data. All EM systems need these.
+
+.sect .bss
+begbss:
+.define hol0
+.comm hol0, 8                ! line number and filename (for debugging)
+
+.define _errno
+.comm _errno, 4              ! Posix errno storage
+
+.define .trppc, .ignmask
+.comm .trppc, 4              ! ptr to user trap handler
+.comm .ignmask, 4            ! user trap ignore mask 

plat/osx386/build-pkg.lua

@@ -0,0 +1,24 @@
+include("plat/build.lua")
+
+ackfile {
+	name = "boot",
+	srcs = { "./boot.s" },
+	vars = { plat = "osx386" }
+}
+
+build_plat_libs {
+	name = "libs",
+	arch = "i386",
+	plat = "osx386",
+}
+
+installable {
+	name = "pkg",
+	map = {
+		"+tools",
+		"+libs",
+		"./include+pkg",
+		["$(PLATIND)/osx386/boot.o"] = "+boot",
+		["$(PLATIND)/osx386/libsys.a"] = "./libsys+lib",
+	}
+}

plat/osx386/build-tools.lua

@@ -0,0 +1,9 @@
+return installable {
+	name = "tools",
+	map = {
+		["$(PLATIND)/descr/osx386"] = "./descr",
+		"plat/linux386+tools",
+		"plat/osx/cvmach+pkg",
+		"util/opt+pkg",
+	}
+}

plat/osx386/descr

@@ -0,0 +1,80 @@
+# plat/osx386/descr
+
+var w=4
+var wa=4
+var p={w}
+var pa={w}
+var s=2
+var sa={s}
+var l={w}
+var la={w}
+var f={w}
+var fa={w}
+var d=8
+var da={d}
+var x=8
+var xa={x}
+var ARCH=i386
+var PLATFORM=osx386
+var PLATFORMDIR={EM}/share/ack/{PLATFORM}
+var CPP_F=-D__unix
+var ALIGN=-a0:4 -a1:4 -a2:4096 -a3:4 -b0:0x1114
+var C_LIB={PLATFORMDIR}/libc-ansi.a
+# bitfields reversed for compatibility with (g)cc.
+var CC_ALIGN=-Vr
+var OLD_C_LIB={C_LIB}
+var MACHOPT_F=-m10
+var EGO_PLAT_FLAGS=-M{EM}/share/ack/ego/{ARCH}.descr
+
+# Override the setting in fe so that files compiled for osx386 can see
+# the platform-specific headers.
+
+var C_INCLUDES=-I{PLATFORMDIR}/include -I{EM}/share/ack/include/ansi
+
+name be
+	from .m.g
+	to .s
+	program {EM}/lib/ack/linux386/ncg
+	mapflag -gdb GF=-gdb
+	args {GF?} <
+	stdout
+	need .e
+end
+name as
+	from .s.so
+	to .o
+	program {EM}/lib/ack/linux386/as
+	args - -o > <
+	prep cond
+end
+name led
+	from .o.a
+	to .out
+	program {EM}/lib/ack/em_led
+	mapflag -l* LNAME={PLATFORMDIR}/lib*
+	mapflag -fp FLOATS={EM}/{LIB}fp
+	args {ALIGN} {SEPID?} \
+	    (.e:{HEAD}={PLATFORMDIR}/boot.o) \
+		({RTS}:.ocm.b={PLATFORMDIR}/c-ansi.o) \
+		({RTS}:.c={PLATFORMDIR}/c-ansi.o) \
+		({RTS}:.mod={PLATFORMDIR}/modula2.o) \
+		({RTS}:.p={PLATFORMDIR}/pascal.o) \
+		-o > < \
+		(.p:{TAIL}={PLATFORMDIR}/libpascal.a) \
+		(.b:{TAIL}={PLATFORMDIR}/libbasic.a) \
+		(.mod:{TAIL}={PLATFORMDIR}/libmodula2.a) \
+		(.ocm:{TAIL}={PLATFORMDIR}/liboccam.a) \
+		(.ocm.b.mod.c.p:{TAIL}={PLATFORMDIR}/libc.a) \
+		{FLOATS?} \
+		(.e:{TAIL}={PLATFORMDIR}/libem.a \
+		           {PLATFORMDIR}/libsys.a \
+		           {PLATFORMDIR}/libend.a)
+	linker
+end
+name cv
+	from .out
+	to .exe
+	program {EM}/lib/ack/cvmach
+	args -m7 < >
+	outfile osx386.exe
+end

plat/osx386/include/build.lua

@@ -0,0 +1,24 @@
+include("plat/build.lua")
+
+headermap = {}
+packagemap = {}
+
+local function addheader(h)
+	headermap[h] = "plat/osx/include/"..h
+	packagemap["$(PLATIND)/osx386/include/"..h] = "plat/osx/include/"..h
+end
+
+addheader("ack/config.h")
+addheader("sys/mman.h")
+addheader("sys/types.h")
+addheader("unistd.h")
+
+acklibrary {
+	name = "headers",
+	hdrs = headermap
+}
+
+installable {
+	name = "pkg",
+	map = packagemap
+}

plat/osx386/libsys/_exit.s

@@ -0,0 +1,5 @@
+.sect .text
+.define __exit
+__exit:
+	mov eax, 1
+	int 0x80

plat/osx386/libsys/build.lua

@@ -0,0 +1,31 @@
+acklibrary {
+	name = "lib",
+	srcs = {
+		"./_exit.s",
+		"./close.s",
+		"./getpid.s",
+		"./gettimeofday.s",
+		"./ioctl.s",
+		"./kill.s",
+		"./lseek.s",
+		"./mmap.s",
+		"./mprotect.s",
+		"./open.s",
+		"./read.s",
+		"./set_errno.s",
+		"./sigaction.s",
+		"./write.s",
+		"plat/linux/libsys/errno.s",
+		"plat/osx/libsys/brk.c",
+		"plat/osx/libsys/creat.c",
+		"plat/osx/libsys/isatty.c",
+		"plat/osx/libsys/signal.c",
+	},
+	deps = {
+		"lang/cem/libcc.ansi/headers+headers",
+		"plat/osx386/include+headers",
+	},
+	vars = {
+		plat = "osx386"
+	}
+}

plat/osx386/libsys/close.s

@@ -0,0 +1,7 @@
+.sect .text
+.define _close
+_close:
+	mov eax, 6
+	int 0x80
+	jb .set_errno
+	ret

plat/osx386/libsys/getpid.s

@@ -0,0 +1,7 @@
+.sect .text
+.define _getpid
+_getpid:
+	mov eax, 20
+	int 0x80
+	jb .set_errno
+	ret

plat/osx386/libsys/gettimeofday.s

@@ -0,0 +1,7 @@
+.sect .text
+.define _gettimeofday
+_gettimeofday:
+	mov eax, 116
+	int 0x80
+	jb .set_errno
+	ret

plat/osx386/libsys/ioctl.s

@@ -0,0 +1,7 @@
+.sect .text
+.define _ioctl
+_ioctl:
+	mov eax, 54
+	int 0x80
+	jb .set_errno
+	ret

plat/osx386/libsys/kill.s

@@ -0,0 +1,7 @@
+.sect .text
+.define _kill
+_kill:
+	mov eax, 37
+	int 0x80
+	jb .set_errno
+	ret

plat/osx386/libsys/lseek.s

@@ -0,0 +1,17 @@
+.sect .text
+.define _lseek
+_lseek:
+	! ack passes 4-byte off_t, but system call takes 8-byte off_t
+	mov eax, esp
+	push 12(eax)		! whence
+	push 0			! offset (high long)
+	push 8(eax)		! offset (low long)
+	push 4(eax)		! fd
+	call 1f
+	add esp, 16
+	ret
+1:
+	mov eax, 199
+	int 0x80
+	jb .set_errno
+	ret

plat/osx386/libsys/mmap.s

@@ -0,0 +1,20 @@
+.sect .text
+.define _mmap
+_mmap:
+	! ack passes 4-byte off_t, but system call takes 8-byte off_t
+	mov eax, esp
+	push 0			! offset (high long)
+	push 24(eax)		! offset (low long)
+	push 20(eax)		! fd
+	push 16(eax)		! flags
+	push 12(eax)		! protection
+	push 8(eax)		! length
+	push 4(eax)		! address
+	call 1f
+	add esp, 28
+	ret
+1:
+	mov eax, 197
+	int 0x80
+	jb .set_errno
+	ret

plat/osx386/libsys/mprotect.s

@@ -0,0 +1,7 @@
+.sect .text
+.define _mprotect
+_mprotect:
+	mov eax, 74
+	int 0x80
+	jb .set_errno
+	ret

plat/osx386/libsys/open.s

@@ -0,0 +1,7 @@
+.sect .text
+.define _open
+_open:
+	mov eax, 5
+	int 0x80
+	jb .set_errno
+	ret

plat/osx386/libsys/read.s

@@ -0,0 +1,7 @@
+.sect .text
+.define _read
+_read:
+	mov eax, 3
+	int 0x80
+	jb .set_errno
+	ret

plat/osx386/libsys/set_errno.s

@@ -0,0 +1,6 @@
+.sect .text
+.define .set_errno
+.set_errno:
+	mov (_errno), eax
+	mov eax, -1
+	ret

plat/osx386/libsys/sigaction.s

@@ -0,0 +1,59 @@
+! OS X, unlike FreeBSD, requires us to provide our own signal
+! trampoline.  We must change the new action from a struct sigaction
+! to a bigger struct that includes the trampoline.
+
+.sect .text
+.define _sigaction
+_sigaction:
+	mov eax, esp
+	mov ebx, 8(esp)		! ebx = ptr to new action
+	cmp ebx, 0
+	je 1f
+	! push bigger struct
+	push 8(ebx)		! sa_flags
+	push 4(ebx)		! sa_mask
+	push trampoline		! sa_tramp
+	push 0(ebx)		! sa_handler
+	mov ebx, esp
+	jmp 2f
+1:
+	sub esp, 16
+2:
+	push 12(eax)		! ptr to old action
+	push ebx		! ptr to bigger struct
+	push 4(eax)		! sig
+	call 3f
+	add esp, 28
+	ret
+3:
+	mov eax, 46
+	int 0x80
+	jb .set_errno
+	ret
+
+trampoline:
+	! 4(esp) = handler
+	! 8(esp) = info style
+	! 12(esp) = sig
+	! 16(esp) = info
+	! 20(esp) = context
+
+	! Call handler(sig, info, context)
+	mov eax, esp
+	push 20(eax)
+	push 16(eax)
+	push 12(eax)
+	call 4(eax)
+	add esp, 12
+
+	! Return from trampoline.
+	mov eax, esp
+	push 8(eax)		! info style
+	push 20(eax)		! context
+	sub esp, 4
+	mov eax, 184		! sigreturn
+	int 0x80
+
+	! Only if sigreturn() fails:
+	mov eax, 1		! exit
+	int 0x80

plat/osx386/libsys/write.s

@@ -0,0 +1,7 @@
+.sect .text
+.define _write
+_write:
+	mov eax, 4
+	int 0x80
+	jb .set_errno
+	ret

plat/osxppc/boot.s

@@ -0,0 +1,60 @@
+! boot.s for osx386
+
+! Declare segments (the order is important).
+
+.sect .text
+.sect .rom
+.sect .data
+.sect .bss
+
+.sect .text
+
+begtext:
+	! This code is placed at the entry point of the Mach-o
+	! executable and is the first thing that runs.
+	!
+	! On entry, the stack looks like this:
+	!
+	! sp+...          NULL
+	! sp+8+(4*argc)   env (X quads)
+	! sp+4+(4*argc)   NULL
+	! sp+4            argv (argc quads)
+	! sp              argc
+	!
+	! The ACK actually expects:
+	!
+	! sp+8            argc
+	! sp+4            ptr to argv
+	! sp              ptr to env
+
+	lwz r3, 0(sp)            ! r3 = argc
+	addi r4, sp, 4           ! r4 = argv
+	rlwinm r5, r3, 32-2, 2, 31 ! shift left 2 bits
+	add r5, r5, r4 
+	addi r5, r5, 8           ! r5 = env
+	
+	stwu r5, -4(sp)
+	stwu r4, -4(sp)
+	stwu r3, -4(sp)
+	
+	b __m_a_i_n
+
+.sect rom
+begrom:
+
+.sect .data
+begdata:
+
+! Some magic data. All EM systems need these.
+
+.sect .bss
+begbss:
+.define hol0
+.comm hol0, 8                ! line number and filename (for debugging)
+
+.define _errno
+.comm _errno, 4              ! Posix errno storage
+
+.define .trppc, .ignmask
+.comm .trppc, 4              ! ptr to user trap handler
+.comm .ignmask, 4            ! user trap ignore mask 

plat/osxppc/build-pkg.lua

@@ -0,0 +1,24 @@
+include("plat/build.lua")
+
+ackfile {
+	name = "boot",
+	srcs = { "./boot.s" },
+	vars = { plat = "osxppc" }
+}
+
+build_plat_libs {
+	name = "libs",
+	arch = "powerpc",
+	plat = "osxppc",
+}
+
+installable {
+	name = "pkg",
+	map = {
+		"+tools",
+		"+libs",
+		"./include+pkg",
+		["$(PLATIND)/osxppc/boot.o"] = "+boot",
+		["$(PLATIND)/osxppc/libsys.a"] = "./libsys+lib",
+	}
+}

plat/osxppc/build-tools.lua

@@ -0,0 +1,9 @@
+return installable {
+	name = "tools",
+	map = {
+		["$(PLATIND)/descr/osxppc"] = "./descr",
+		"plat/linuxppc+tools",
+		"plat/osx/cvmach+pkg",
+		"util/opt+pkg",
+	}
+}

plat/osxppc/descr

@@ -0,0 +1,81 @@
+# plat/osxppc/descr
+
+var w=4
+var wa=4
+var p={w}
+var pa={w}
+var s=2
+var sa={s}
+var l={w}
+var la={w}
+var f={w}
+var fa={w}
+var d=8
+var da={d}
+var x=8
+var xa={x}
+var ARCH=powerpc
+var PLATFORM=osxppc
+var PLATFORMDIR={EM}/share/ack/{PLATFORM}
+var CPP_F=-D__unix
+var ALIGN=-a0:4 -a1:4 -a2:4096 -a3:4 -b0:0x1174
+var C_LIB={PLATFORMDIR}/libc-ansi.a
+# bitfields reversed for compatibility with (g)cc.
+# XXX this is from linux386, might be wrong for osxppc
+var CC_ALIGN=-Vr
+var OLD_C_LIB={C_LIB}
+var MACHOPT_F=-m10
+# var EGO_PLAT_FLAGS=-M{EM}/share/ack/ego/{ARCH}.descr
+
+# Override the setting in fe so that files compiled for osxppc can see
+# the platform-specific headers.
+
+var C_INCLUDES=-I{PLATFORMDIR}/include -I{EM}/share/ack/include/ansi
+
+name be
+	from .m.g
+	to .s
+	program {EM}/lib/ack/linuxppc/ncg
+	mapflag -gdb GF=-gdb
+	args {GF?} <
+	stdout
+	need .e
+end
+name as
+	from .s.so
+	to .o
+	program {EM}/lib/ack/linuxppc/as
+	args - -o > <
+	prep cond
+end
+name led
+	from .o.a
+	to .out
+	program {EM}/lib/ack/em_led
+	mapflag -l* LNAME={PLATFORMDIR}/lib*
+	mapflag -fp FLOATS={EM}/{LIB}fp
+	args {ALIGN} {SEPID?} \
+	    (.e:{HEAD}={PLATFORMDIR}/boot.o) \
+		({RTS}:.ocm.b={PLATFORMDIR}/c-ansi.o) \
+		({RTS}:.c={PLATFORMDIR}/c-ansi.o) \
+		({RTS}:.mod={PLATFORMDIR}/modula2.o) \
+		({RTS}:.p={PLATFORMDIR}/pascal.o) \
+		-o > < \
+		(.p:{TAIL}={PLATFORMDIR}/libpascal.a) \
+		(.b:{TAIL}={PLATFORMDIR}/libbasic.a) \
+		(.mod:{TAIL}={PLATFORMDIR}/libmodula2.a) \
+		(.ocm:{TAIL}={PLATFORMDIR}/liboccam.a) \
+		(.ocm.b.mod.c.p:{TAIL}={PLATFORMDIR}/libc.a) \
+		{FLOATS?} \
+		(.e:{TAIL}={PLATFORMDIR}/libem.a \
+		           {PLATFORMDIR}/libsys.a \
+		           {PLATFORMDIR}/libend.a)
+	linker
+end
+name cv
+	from .out
+	to .exe
+	program {EM}/lib/ack/cvmach
+	args -m18 < >
+	outfile osxppc.exe
+end

plat/osxppc/include/build.lua

@@ -0,0 +1,24 @@
+include("plat/build.lua")
+
+headermap = {}
+packagemap = {}
+
+local function addheader(h)
+	headermap[h] = "plat/osx/include/"..h
+	packagemap["$(PLATIND)/osxppc/include/"..h] = "plat/osx/include/"..h
+end
+
+addheader("ack/config.h")
+addheader("sys/mman.h")
+addheader("sys/types.h")
+addheader("unistd.h")
+
+acklibrary {
+	name = "headers",
+	hdrs = headermap
+}
+
+installable {
+	name = "pkg",
+	map = packagemap
+}

plat/osxppc/libsys/_exit.s

@@ -0,0 +1,6 @@
+.sect .text
+.define __exit
+__exit:
+	addi r0, r0, 1		! _exit
+	lwz r3, 0(sp)		! status
+	sc 0

plat/osxppc/libsys/build.lua

@@ -0,0 +1,31 @@
+acklibrary {
+	name = "lib",
+	srcs = {
+		"./_exit.s",
+		"./close.s",
+		"./getpid.s",
+		"./gettimeofday.s",
+		"./ioctl.s",
+		"./kill.s",
+		"./lseek.s",
+		"./mmap.s",
+		"./mprotect.s",
+		"./open.s",
+		"./read.s",
+		"./set_errno.s",
+		"./sigaction.s",
+		"./write.s",
+		"plat/linuxppc/libsys/trap.s",
+		"plat/osx/libsys/brk.c",
+		"plat/osx/libsys/creat.c",
+		"plat/osx/libsys/isatty.c",
+		"plat/osx/libsys/signal.c",
+	},
+	deps = {
+		"lang/cem/libcc.ansi/headers+headers",
+		"plat/osxppc/include+headers",
+	},
+	vars = {
+		plat = "osxppc"
+	}
+}

plat/osxppc/libsys/close.s

@@ -0,0 +1,8 @@
+.sect .text
+.define _close
+_close:
+	addi r0, r0, 6		! close
+	lwz r3, 0(sp)		! fd
+	sc 0
+	b .set_errno
+	bclr 20, 0, 0

plat/osxppc/libsys/getpid.s

@@ -0,0 +1,7 @@
+.sect .text
+.define _getpid
+_getpid:
+	addi r0, r0, 20		! getpid
+	sc 0
+	b .set_errno
+	bclr 20, 0, 0

plat/osxppc/libsys/gettimeofday.s

@@ -0,0 +1,9 @@
+.sect .text
+.define _gettimeofday
+_gettimeofday:
+	addi r0, r0, 116	! gettimeofday
+	lwz r3, 0(sp)		! timeval pointer
+	lwz r4, 4(sp)		! timezone pointer
+	sc 0
+	b .set_errno
+	bclr 20, 0, 0

plat/osxppc/libsys/ioctl.s

@@ -0,0 +1,10 @@
+.sect .text
+.define _ioctl
+_ioctl:
+	addi r0, r0, 54		! ioctl
+	lwz r3, 0(sp)		! fd
+	lwz r4, 4(sp)		! command
+	lwz r5, 8(sp)		! argument pointer
+	sc 0
+	b .set_errno
+	bclr 20, 0, 0

plat/osxppc/libsys/kill.s

@@ -0,0 +1,9 @@
+.sect .text
+.define _kill
+_kill:
+	addi r0, r0, 37		! kill
+	lwz r3, 0(sp)		! pid
+	lwz r4, 4(sp)		! signal
+	sc 0
+	b .set_errno
+	bclr 20, 0, 0

plat/osxppc/libsys/lseek.s

@@ -0,0 +1,13 @@
+.sect .text
+.define _lseek
+_lseek:
+	addi r0, r0, 199	! lseek
+	lwz r3, 0(sp)		! fd
+	! ack passes 4-byte off_t, but system call takes 8-byte off_t
+	addi r4, r0, 0		! offset (high word)
+	lwz r5, 4(sp)		! offset (low word)
+	lwz r6, 8(sp)		! whence
+	sc 0
+	b .set_errno
+	or r3, r4, r4		! return offset (low word)
+	bclr 20, 0, 0

plat/osxppc/libsys/mmap.s

@@ -0,0 +1,15 @@
+.sect .text
+.define _mmap
+_mmap:
+	addi r0, r0, 197	! mmap
+	lwz r3, 0(sp)		! address
+	lwz r4, 4(sp)		! length
+	lwz r5, 8(sp)		! protection
+	lwz r6, 12(sp)		! flags
+	lwz r7, 16(sp)		! fd
+	! ack passes 4-byte off_t, but system call takes 8-byte off_t
+	addi r8, r0, 0		! offset (high word)
+	lwz r9, 20(sp)		! offset (low word)
+	sc 0
+	b .set_errno
+	bclr 20, 0, 0

plat/osxppc/libsys/mprotect.s

@@ -0,0 +1,10 @@
+.sect .text
+.define _mprotect
+_mprotect:
+	addi r0, r0, 74		! mprotect
+	lwz r3, 0(sp)		! address
+	lwz r4, 4(sp)		! length
+	lwz r5, 8(sp)		! protection
+	sc 0
+	b .set_errno
+	bclr 20, 0, 0

plat/osxppc/libsys/open.s

@@ -0,0 +1,10 @@
+.sect .text
+.define _open
+_open:
+	addi r0, r0, 5		! open
+	lwz r3, 0(sp)		! path
+	lwz r4, 4(sp)		! flags
+	lwz r5, 8(sp)		! mode
+	sc 0
+	b .set_errno
+	bclr 20, 0, 0

plat/osxppc/libsys/read.s

@@ -0,0 +1,10 @@
+.sect .text
+.define _read
+_read:
+	addi r0, r0, 3		! read
+	lwz r3, 0(sp)		! fd
+	lwz r4, 4(sp)		! buffer
+	lwz r5, 8(sp)		! buffer size
+	sc 0
+	b .set_errno
+	bclr 20, 0, 0

plat/osxppc/libsys/set_errno.s

@@ -0,0 +1,7 @@
+.sect .text
+.define .set_errno
+.set_errno:
+	li32 r10, _errno
+	stw r3, 0(r10)		! set errno
+	addi r3, r0, -1		! return -1
+	bclr 20, 0, 0

plat/osxppc/libsys/sigaction.s

@@ -0,0 +1,59 @@
+#define IFTRUE 12
+#define ALWAYS 20
+#define EQ 2
+
+! OS X, unlike FreeBSD, requires us to provide our own signal
+! trampoline.  We must change the new action from a struct sigaction
+! to a bigger struct that includes the trampoline.
+
+.sect .text
+.define _sigaction
+_sigaction:
+	addi r0, r0, 46		! sigaction
+	lwz r3, 0(sp)		! sig
+	lwz r4, 4(sp)		! ptr to new action
+	lwz r5, 8(sp)		! ptr to old action
+	or. r6, r4, r4
+	bc IFTRUE, EQ, 1f	! skip if new action is NULL
+
+	! We may use the "red zone" from -224(sp) to 0(sp).
+	addi r4, sp, -16	! r4 = bigger struct
+	lwz r7, 0(r6)
+	stw r7, 0(r4)		! sa_handler
+	li32 r7, trampoline
+	stw r7, 4(r4)		! sa_tramp
+	lwz r7, 4(r6)
+	stw r7, 8(r4)		! sa_mask
+	lwz r7, 8(r6)
+	stw r7, 12(r4)		! sa_flags
+1:
+	sc 0
+	b .set_errno
+	bclr 20, 0, 0
+
+trampoline:
+	! r3 = handler
+	! r4 = info style
+	! r5 = sig
+	! r6 = info
+	! r7 = context
+	or r31, r4, r4		! ack preserves r30, r31
+	or r30, r7, r7
+
+	! Call handler(sig, info, context).
+	mtspr ctr, r3
+	stwu r7, -4(sp)		! ack expects arguments on stack
+	stwu r6, -4(sp)
+	stwu r5, -4(sp)
+	bcctrl ALWAYS, 0, 0
+
+	! Return from trampoline.
+	addi r0, r0, 184	! sigreturn
+	or r3, r30, r30		! context
+	or r4, r31, r31		! info style
+	sc 0
+	ori r0, r0, 0		! nop
+
+	! Only if sigreturn() fails:
+	addi r0, r0, 1		! exit
+	sc 0

plat/osxppc/libsys/write.s

@@ -0,0 +1,10 @@
+.sect .text
+.define _write
+_write:
+	addi r0, r0, 4		! write
+	lwz r3, 0(sp)		! fd
+	lwz r4, 4(sp)		! buffer
+	lwz r5, 8(sp)		! buffer size
+	sc 0
+	b .set_errno
+	bclr 20, 0, 0