cleanup and fix warnings

arch/at91sam3x8e/entry.c

@@ -9,7 +9,6 @@
 
 #include <errno.h>
 #include <stddef.h>
-#include <unistd.h>
 
 void arch_enter(void *sp)
 {
@@ -20,13 +19,13 @@ void arch_enter(void *sp)
 	int sc_ret;
 
 	if (sc_num > NSYSCALLS) {
-		arch_syscall_set_rval(regs, -EINVAL);
+		arch_syscall_set_rval(regs, -ENOSYS);
 		return;
 	}
 
 	handler = sys_table[sc_num];
 	if (handler == NULL) {
-		arch_syscall_set_rval(regs, -EINVAL);
+		arch_syscall_set_rval(regs, -ENOSYS);
 		return;
 	}
 

arch/at91sam3x8e/serial.c

@@ -21,7 +21,6 @@ struct arch_serial_interface arch_serial_default_interface = {
 	.tx_current = NULL,
 	.tx_next = NULL,
 	.interface = {
-		.tx = NULL,
 		.rx = NULL,
 		.id = 0,
 		.baud = 0,
@@ -31,8 +30,6 @@ struct serial_interface *serial_default_interface = &arch_serial_default_interfa
 
 int arch_serial_init(struct serial_interface *interface)
 {
-	struct arch_serial_interface *arch_iface = to_arch_serial_interface(interface);
-
 	if (interface->baud <= 0 || interface->id != 0)
 		return -1;
 

include/arch/at91sam3x8e/hardware.h

@@ -62,7 +62,7 @@ struct reg_snapshot {
 #define arch_syscall_arg5(reg_snap) ((reg_snap)->sw.r4)
 #define arch_syscall_arg6(reg_snap) ((reg_snap)->sw.r5)
 
-#define arch_syscall_set_rval(reg_snap, val) ((reg_snap)->hw.r0 = (val));
+#define arch_syscall_set_rval(reg_snap, val) ((reg_snap)->hw.r0 = (word_t)(val));
 
 /*
  * Real-time Timer (RTT)

kernel/fs/write.c

@@ -10,9 +10,9 @@
 #include <stddef.h>
 #include <toolchain.h>
 
-int sys_write(int fd, __user const void *buf, size_t len, size_t off)
+ssize_t sys_write(int fd, __user const void *buf, size_t len, size_t off)
 {
-	int ret;
+	ssize_t ret;
 	void *copy;
 
 	if (fd != 1) /* we only support stdout (serial console) right now ... */
@@ -23,10 +23,10 @@ int sys_write(int fd, __user const void *buf, size_t len, size_t off)
 	copy = malloc(len);
 	if (copy == NULL)
 		return -ENOMEM;
-	ret = (int)copy_from_user(copy, buf, len);
+	ret = (ssize_t)copy_from_user(copy, buf, (size_t)len);
 
 	/* TODO: reschedule if blocking */
-	ret = serial_write(serial_default_interface, copy, ret);
+	ret = serial_write(serial_default_interface, copy, (size_t)ret);
 
 	return ret;
 }

kernel/serial.c

@@ -50,13 +50,13 @@ ssize_t serial_read(void *dest, struct serial_interface *interface, size_t len)
 
 ssize_t serial_write(struct serial_interface *interface, const void *data, size_t len)
 {
-	size_t ret;
+	ssize_t ret;
 
 	atomic_enter();
 	ret = arch_serial_write(interface, data, len);
 	atomic_leave();
 
-	return (ssize_t)ret;
+	return ret;
 }
 
 /*