diff --git a/plat/linux/libsys/sigprocmask.c b/plat/linux/libsys/sigprocmask.c
new file mode 100644
index 000000000..ad1b339c2
--- /dev/null
+++ b/plat/linux/libsys/sigprocmask.c
@@ -0,0 +1,7 @@
+#include <signal.h>
+#include "libsys.h"
+
+int sigprocmask(int flags, const sigset_t *new, sigset_t *old)
+{
+	return _syscall(__NR_sigprocmask, flags, (quad) new, (quad) old);
+}
diff --git a/plat/linux386/include/unistd.h b/plat/linux386/include/unistd.h
index 5c6f31ef4..8c8637c09 100644
--- a/plat/linux386/include/unistd.h
+++ b/plat/linux386/include/unistd.h
@@ -56,7 +56,6 @@ extern int write(int fd, void* buffer, size_t count);
 extern off_t lseek(int fildes, off_t offset, int whence);
 extern int fcntl(int fd, int op, ...);
 extern int unlink(const char* path);
-extern int remove(const char* path);
 
 /* Special variables */
 
@@ -117,8 +116,16 @@ typedef int sig_atomic_t;
 
 #define _NSIG           32      /* Biggest signal number + 1
                                    (not including real-time signals).  */
+
+/* sigprocmask */
+#define SIG_BLOCK       0
+#define SIG_UNBLOCK     1
+#define SIG_SETMASK     2
+typedef unsigned long sigset_t;
+
 typedef void (*sighandler_t)(int);
 extern sighandler_t signal(int signum, sighandler_t handler);
+extern int sigprocmask(int, const sigset_t *, sigset_t *);
 extern int raise(int signum);
 
 
diff --git a/plat/linux68k/include/unistd.h b/plat/linux68k/include/unistd.h
index 307192f77..927a20459 100644
--- a/plat/linux68k/include/unistd.h
+++ b/plat/linux68k/include/unistd.h
@@ -55,6 +55,7 @@ extern int read(int fd, void* buffer, size_t count);
 extern int write(int fd, void* buffer, size_t count);
 extern off_t lseek(int fildes, off_t offset, int whence);
 extern int fcntl(int fd, int op, ...);
+extern int unlink(const char* path);
 
 /* Special variables */
 
@@ -67,6 +68,7 @@ extern pid_t getpid(void);
 extern int brk(void* ptr);
 extern void* sbrk(int increment);
 extern int isatty(int d);
+extern int execve(const char *path, char *const argv[], char *const envp[]);
 
 /* Signal handling */
 
@@ -114,8 +116,16 @@ typedef int sig_atomic_t;
 
 #define _NSIG           32      /* Biggest signal number + 1
                                    (not including real-time signals).  */
+
+/* sigprocmask */
+#define SIG_BLOCK       0
+#define SIG_UNBLOCK     1
+#define SIG_SETMASK     2
+typedef unsigned long sigset_t;
+
 typedef void (*sighandler_t)(int);
 extern sighandler_t signal(int signum, sighandler_t handler);
+extern int sigprocmask(int, const sigset_t *, sigset_t *);
 extern int raise(int signum);
 
 
diff --git a/plat/linuxppc/include/unistd.h b/plat/linuxppc/include/unistd.h
index a31bd9f0d..f57705365 100644
--- a/plat/linuxppc/include/unistd.h
+++ b/plat/linuxppc/include/unistd.h
@@ -55,6 +55,7 @@ extern int read(int fd, void* buffer, size_t count);
 extern int write(int fd, void* buffer, size_t count);
 extern off_t lseek(int fildes, off_t offset, int whence);
 extern int fcntl(int fd, int op, ...);
+extern int unlink(const char* path);
 
 /* Special variables */
 
@@ -115,8 +116,34 @@ typedef int sig_atomic_t;
 
 #define _NSIG           32      /* Biggest signal number + 1
                                    (not including real-time signals).  */
+
+/* sigprocmask */
+#define SIG_BLOCK       0
+#define SIG_UNBLOCK     1
+#define SIG_SETMASK     2
+typedef unsigned long sigset_t;
+
+/* sa_flags */
+#define SA_NODEFER      0x40000000UL
+#define SA_RESETHAND    0x80000000UL
+
+struct __siginfo;
+struct sigaction {
+	union {
+		void (*__sa_handler)(int);
+		void (*__sa_sigaction)(int, struct __siginfo *, void *);
+	} __sigaction_u;
+	sigset_t sa_mask;
+	unsigned long sa_flags;
+	void (*sa_restorer)(void);
+};
+#define sa_handler __sigaction_u.__sa_handler
+#define sa_sigaction __sigaction_u.__sa_sigaction
+
 typedef void (*sighandler_t)(int);
+extern int sigaction(int, const struct sigaction *, struct sigaction *);
 extern sighandler_t signal(int signum, sighandler_t handler);
+extern int sigprocmask(int, const sigset_t *, sigset_t *);
 extern int raise(int signum);
 
 
diff --git a/plat/linuxppc/libsys/build.lua b/plat/linuxppc/libsys/build.lua
index e74f3f416..f7b16b378 100644
--- a/plat/linuxppc/libsys/build.lua
+++ b/plat/linuxppc/libsys/build.lua
@@ -1,16 +1,36 @@
 acklibrary {
-    name = "lib",
-    srcs = {
-        "./*.s",
-        "plat/linux/libsys/*.c",
-        "plat/linux/libsys/*.s",
-    },
+	name = "lib",
+	srcs = {
+		"./_syscall.s",
+		"./sigaction.s",
+		"./signal.c",
+		"./trap.s",
+		"plat/linux/libsys/_exit.c",
+		"plat/linux/libsys/_hol0.s",
+		"plat/linux/libsys/close.c",
+		"plat/linux/libsys/creat.c",
+		"plat/linux/libsys/errno.s",
+		"plat/linux/libsys/execve.c",
+		"plat/linux/libsys/getpid.c",
+		"plat/linux/libsys/gettimeofday.c",
+		"plat/linux/libsys/ioctl.c",
+		"plat/linux/libsys/isatty.c",
+		"plat/linux/libsys/kill.c",
+		"plat/linux/libsys/lseek.c",
+		"plat/linux/libsys/open.c",
+		"plat/linux/libsys/read.c",
+		"plat/linux/libsys/sbrk.c",
+		-- omit signal.c
+		"plat/linux/libsys/sigprocmask.c",
+		"plat/linux/libsys/unlink.c",
+		"plat/linux/libsys/write.c",
+	},
 	deps = {
 		"lang/cem/libcc.ansi/headers+headers",
 		"plat/linuxppc/include+headers",
 	},
-    vars = {
-        plat = "linuxppc"
-    }
+	vars = {
+		plat = "linuxppc"
+	}
 }
 
diff --git a/plat/linuxppc/libsys/sigaction.s b/plat/linuxppc/libsys/sigaction.s
new file mode 100644
index 000000000..0509c8e72
--- /dev/null
+++ b/plat/linuxppc/libsys/sigaction.s
@@ -0,0 +1,156 @@
+#define __NR_sigaction		67
+#define SIG_BLOCK		0
+#define SIG_SETMASK		2
+#define MAXSIG			32
+
+/* offsets into our stack frame */
+#define mynew	16	/* new sigaction */
+#define mynset	32	/* new signal set */
+#define myoset	36	/* old signal set */
+#define mysave	40
+#define mysize	56
+
+.sect .text; .sect .rodata; .sect .data; .sect .bss
+
+/*
+ * Linux calls signal handlers with arguments in registers, but the
+ * ACK expects arguments on the stack.  This sigaction() uses a
+ * "bridge" to move the arguments.
+ */
+.sect .text
+.define _sigaction
+_sigaction:
+	mflr	r0
+	subi	r1, r1, mysize
+	stw	r31, mysave+8(r1)
+	stw	r30, mysave+4(r1)
+	stw	r29, mysave(r1)
+	stw	r0, mysave+12(r1)
+	li	r3, 0
+	stw	r3, mynset(r1)	   	! mynset = 0
+	lwz	r29, mysize(r1)		! r29 = signal number
+	lwz	r30, mysize+4(r1)	! r30 = new action
+	lwz	r31, mysize+8(r1)	! r31 = old action
+	/*
+	 * If the new action is non-NULL, the signal number is in
+	 * range 1 to MAXSIG, and the new handler is not SIG_DFL 0
+	 * or SIG_IGN 1, then we interpose our bridge.
+	 */
+	cmpwi	cr0, r30, 0
+	subi	r7, r29, 1		! r7 = index in handlers
+	cmplwi	cr7, r7, MAXSIG		! unsigned comparison
+	beq	cr0, kernel
+	bge	cr7, kernel
+	lwz	r3, 0(r30)		! r3 = new handler
+	clrrwi.	r3, r3, 1
+	beq	cr0, kernel
+	/*
+	 * Block the signal while we build the bridge.  Prevents a
+	 * race if a signal arrives after we change the bridge but
+	 * before we change the action in the kernel.
+	 */
+	li	r4, 1
+	slw	r4, r4, r7
+	stw	r4, mynset(r1)		! mynmask = 1 << (signal - 1)
+	li	r3, SIG_BLOCK
+	la	r4, mynset(r1)
+	la	r5, myoset(r1)
+	stw	r3, 0(r1)
+	stw	r4, 4(r1)
+	stw	r5, 8(r1)
+	bl	_sigprocmask
+	/*
+	 * Point our bridge to the new signal handler.  Then copy the
+	 * new sigaction but point it to our bridge.
+	 */
+	lis	r6, hi16[handlers]
+	ori	r6, r6, lo16[handlers]
+	subi	r7, r29, 1
+	slwi	r7, r7, 2
+	lwz	r3, 0(r30)		! r3 = new handler
+	stwx	r3, r6, r7		! put it in array of handlers
+	lis	r3, hi16[bridge]
+	ori	r3, r3, lo16[bridge]
+	lwz	r4, 4(r30)
+	lwz	r5, 8(r30)
+	lwz	r6, 12(r30)
+	stw	r3, mynew(r1)		! sa_handler or sa_sigaction
+	stw	r4, mynew+4(r1)		! sa_mask
+	stw	r5, mynew+8(r1)		! sa_flags
+	stw	r6, mynew+12(r1)	! sa_restorer
+	la	r30, mynew(r1)
+kernel:
+	li	r3, __NR_sigaction
+	stw	r3, 0(r1)
+	stw	r29, 4(r1)
+	stw	r30, 8(r1)
+	stw	r31, 12(r1)
+	bl	__syscall
+	/*
+	 * If we blocked the signal, then restore the old signal mask.
+	 */
+	lwz	r3, mynset(r1)
+	cmpwi	cr0, r3, 0
+	beq	cr0, fixold
+	li	r3, SIG_SETMASK
+	la	r4, myoset(r1)
+	li	r5, 0
+	stw	r3, 0(r1)
+	stw	r4, 4(r1)
+	stw	r5, 8(r1)
+	bl	_sigprocmask
+	/*
+	 * If the old sigaction is non-NULL and points to our bridge,
+	 * then point it to the signal handler.
+	 */
+fixold:
+	cmpwi	cr0, r31, 0
+	beq	cr0, leave
+	lis	r3, hi16[bridge]
+	ori	r3, r3, lo16[bridge]
+	lwz	r4, 0(r31)
+	cmpw	cr0, r3, r4
+	bne	cr0, leave
+	lis	r6, hi16[handlers]
+	ori	r6, r6, lo16[handlers]
+	subi	r7, r29, 1
+	slwi	r7, r7, 2
+	lwzx	r3, r6, r7	! get it from array of handlers
+	stw	r3, 0(r31)	! put it in old sigaction
+leave:
+	lwz	r0, mysave+12(r1)
+	lwz	r29, mysave(r1)
+	lwz	r30, mysave+4(r1)
+	lwz	r31, mysave+8(r1)
+	addi	r1, r1, mysize
+	mtlr	r0
+	blr			! return from sigaction
+
+/*
+ * Linux calls bridge(signum) or bridge(signum, info, context) with
+ * arguments in registers r3, r4, r5.
+ */
+bridge:
+	mflr	r0
+	subi	r1, r1, 16
+	stw	r0, 12(r1)
+	stw	r3, 0(r1)	! signal number
+	stw	r4, 4(r1)	! info
+	stw	r5, 8(r1)	! context
+
+	lis	r6, hi16[handlers]
+	ori	r6, r6, lo16[handlers]
+	subi	r7, r3, 1
+	slwi	r7, r7, 2
+	lwzx	r6, r6, r7
+	mtctr	r6
+	bctrl			! call our signal handler
+
+	lwz	r0, 12(r1)
+	addi	r1, r1, 16
+	mtlr	r0
+	blr			! return from bridge
+
+.sect .bss
+handlers:
+	.space 4 * MAXSIG	! array of signal handlers
diff --git a/plat/linuxppc/libsys/signal.c b/plat/linuxppc/libsys/signal.c
new file mode 100644
index 000000000..0ed1918e1
--- /dev/null
+++ b/plat/linuxppc/libsys/signal.c
@@ -0,0 +1,19 @@
+#include <signal.h>
+
+/*
+ * Uses our bridge in sigaction.s when calling the signal handler.
+ * Mimics Linux __NR_signal by using SA_NODEFER | SA_RESETHAND.
+ */
+sighandler_t signal(int signum, sighandler_t handler) {
+	struct sigaction new, old;
+	int i;
+
+	new.sa_handler = handler;
+	new.sa_mask = 0; /* empty set */
+	new.sa_flags = SA_NODEFER | SA_RESETHAND;
+
+	i = sigaction(signum, &new, &old);
+	if (i < 0)
+		return SIG_ERR;
+	return old.sa_handler;
+}