diff --git a/src/add-ons/accelerants/intel_extreme/hooks.cpp b/src/add-ons/accelerants/intel_extreme/hooks.cpp
index 9fa1090222..5d394d5bbe 100644
--- a/src/add-ons/accelerants/intel_extreme/hooks.cpp
+++ b/src/add-ons/accelerants/intel_extreme/hooks.cpp
@@ -17,106 +17,106 @@ get_accelerant_hook(uint32 feature, void *data)
 	switch (feature) {
 		/* general */
 		case B_INIT_ACCELERANT:
-			return intel_init_accelerant;
+			return (void*)intel_init_accelerant;
 		case B_UNINIT_ACCELERANT:
-			return intel_uninit_accelerant;
+			return (void*)intel_uninit_accelerant;
 		case B_CLONE_ACCELERANT:
-			return intel_clone_accelerant;
+			return (void*)intel_clone_accelerant;
 		case B_ACCELERANT_CLONE_INFO_SIZE:
-			return intel_accelerant_clone_info_size;
+			return (void*)intel_accelerant_clone_info_size;
 		case B_GET_ACCELERANT_CLONE_INFO:
-			return intel_get_accelerant_clone_info;
+			return (void*)intel_get_accelerant_clone_info;
 		case B_GET_ACCELERANT_DEVICE_INFO:
-			return intel_get_accelerant_device_info;
+			return (void*)intel_get_accelerant_device_info;
 		case B_ACCELERANT_RETRACE_SEMAPHORE:
-			return intel_accelerant_retrace_semaphore;
+			return (void*)intel_accelerant_retrace_semaphore;
 
 		/* mode configuration */
 		case B_ACCELERANT_MODE_COUNT:
-			return intel_accelerant_mode_count;
+			return (void*)intel_accelerant_mode_count;
 		case B_GET_MODE_LIST:
-			return intel_get_mode_list;
+			return (void*)intel_get_mode_list;
 		case B_PROPOSE_DISPLAY_MODE:
-			return intel_propose_display_mode;
+			return (void*)intel_propose_display_mode;
 		case B_SET_DISPLAY_MODE:
-			return intel_set_display_mode;
+			return (void*)intel_set_display_mode;
 		case B_GET_DISPLAY_MODE:
-			return intel_get_display_mode;
+			return (void*)intel_get_display_mode;
 		case B_GET_FRAME_BUFFER_CONFIG:
-			return intel_get_frame_buffer_config;
+			return (void*)intel_get_frame_buffer_config;
 		case B_GET_PIXEL_CLOCK_LIMITS:
-			return intel_get_pixel_clock_limits;
+			return (void*)intel_get_pixel_clock_limits;
 		case B_MOVE_DISPLAY:
-			return intel_move_display;
+			return (void*)intel_move_display;
 		case B_SET_INDEXED_COLORS:
-			return intel_set_indexed_colors;
+			return (void*)intel_set_indexed_colors;
 		case B_GET_TIMING_CONSTRAINTS:
-			return intel_get_timing_constraints;
+			return (void*)intel_get_timing_constraints;
 
 		/* DPMS */
 		case B_DPMS_CAPABILITIES:
-			return intel_dpms_capabilities;
+			return (void*)intel_dpms_capabilities;
 		case B_DPMS_MODE:
-			return intel_dpms_mode;
+			return (void*)intel_dpms_mode;
 		case B_SET_DPMS_MODE:
-			return intel_set_dpms_mode;
+			return (void*)intel_set_dpms_mode;
 
 		/* cursor managment */
 		case B_SET_CURSOR_SHAPE:
 			if (gInfo->cursor_memory != NULL)
-				return intel_set_cursor_shape;
+				return (void*)intel_set_cursor_shape;
 		case B_MOVE_CURSOR:
 			if (gInfo->cursor_memory != NULL)
-				return intel_move_cursor;
+				return (void*)intel_move_cursor;
 		case B_SHOW_CURSOR:
 			if (gInfo->cursor_memory != NULL)
-				return intel_show_cursor;
+				return (void*)intel_show_cursor;
 
 			return NULL;
 
 		/* engine/synchronization */
 		case B_ACCELERANT_ENGINE_COUNT:
-			return intel_accelerant_engine_count;
+			return (void*)intel_accelerant_engine_count;
 		case B_ACQUIRE_ENGINE:
-			return intel_acquire_engine;
+			return (void*)intel_acquire_engine;
 		case B_RELEASE_ENGINE:
-			return intel_release_engine;
+			return (void*)intel_release_engine;
 		case B_WAIT_ENGINE_IDLE:
-			return intel_wait_engine_idle;
+			return (void*)intel_wait_engine_idle;
 		case B_GET_SYNC_TOKEN:
-			return intel_get_sync_token;
+			return (void*)intel_get_sync_token;
 		case B_SYNC_TO_TOKEN:
-			return intel_sync_to_token;
+			return (void*)intel_sync_to_token;
 
 		/* 2D acceleration */
 		case B_SCREEN_TO_SCREEN_BLIT:
-			return intel_screen_to_screen_blit;
+			return (void*)intel_screen_to_screen_blit;
 		case B_FILL_RECTANGLE:
-			return intel_fill_rectangle;
+			return (void*)intel_fill_rectangle;
 		case B_INVERT_RECTANGLE:
-			return intel_invert_rectangle;
+			return (void*)intel_invert_rectangle;
 		case B_FILL_SPAN:
-			return intel_fill_span;
+			return (void*)intel_fill_span;
 
 		// overlay
 		case B_OVERLAY_COUNT:
-			return intel_overlay_supported_spaces;
+			return (void*)intel_overlay_supported_spaces;
 		case B_OVERLAY_SUPPORTED_SPACES:
-			return intel_overlay_supported_spaces;
+			return (void*)intel_overlay_supported_spaces;
 		case B_OVERLAY_SUPPORTED_FEATURES:
-			return intel_overlay_supported_features;
+			return (void*)intel_overlay_supported_features;
 		case B_ALLOCATE_OVERLAY_BUFFER:
-			return intel_allocate_overlay_buffer;
+			return (void*)intel_allocate_overlay_buffer;
 		case B_RELEASE_OVERLAY_BUFFER:
-			return intel_release_overlay_buffer;
+			return (void*)intel_release_overlay_buffer;
 		case B_GET_OVERLAY_CONSTRAINTS:
-			return intel_get_overlay_constraints;
+			return (void*)intel_get_overlay_constraints;
 		case B_ALLOCATE_OVERLAY:
-			return intel_allocate_overlay;
+			return (void*)intel_allocate_overlay;
 		case B_RELEASE_OVERLAY:
-			return intel_release_overlay;
+			return (void*)intel_release_overlay;
 		case B_CONFIGURE_OVERLAY:
-			return intel_configure_overlay;
+			return (void*)intel_configure_overlay;
 	}
 
 	return NULL;
diff --git a/src/add-ons/accelerants/intel_extreme/mode.cpp b/src/add-ons/accelerants/intel_extreme/mode.cpp
index bf09a303a3..283609e3b1 100644
--- a/src/add-ons/accelerants/intel_extreme/mode.cpp
+++ b/src/add-ons/accelerants/intel_extreme/mode.cpp
@@ -11,6 +11,8 @@
 #include "accelerant.h"
 #include "utility.h"
 
+#include <string.h>
+#include <math.h>
 
 #define TRACE_MODE
 #ifdef TRACE_MODE
diff --git a/src/add-ons/accelerants/intel_extreme/overlay.cpp b/src/add-ons/accelerants/intel_extreme/overlay.cpp
index 371bfaa35d..bcba7cbcb4 100644
--- a/src/add-ons/accelerants/intel_extreme/overlay.cpp
+++ b/src/add-ons/accelerants/intel_extreme/overlay.cpp
@@ -16,6 +16,7 @@
 
 #include <math.h>
 #include <stdlib.h>
+#include <string.h>
 
 
 //#define TRACE_OVERLAY
diff --git a/src/add-ons/kernel/drivers/network/bcm570x/b57um.c b/src/add-ons/kernel/drivers/network/bcm570x/b57um.c
index 936030a2b0..e22e366281 100644
--- a/src/add-ons/kernel/drivers/network/bcm570x/b57um.c
+++ b/src/add-ons/kernel/drivers/network/bcm570x/b57um.c
@@ -251,14 +251,14 @@ static struct pci_device_id bcm5700_pci_tbl[] = {
 
 /* -------- BeOS Driver Hooks ------------ */
 
-status_t b57_open(const char *name, uint32 flags, void **cookie);
-status_t b57_close(void *cookie);
-status_t b57_free(void *cookie);
-status_t b57_ioctl(void *cookie,uint32 op,void *data,size_t len);
-status_t b57_read(void *cookie,off_t pos,void *data,size_t *numBytes);
-status_t b57_write(void *cookie,off_t pos,const void *data,size_t *numBytes);
-int32	 b57_interrupt(void *cookie);
-int32 tx_cleanup_thread(void *us);
+static status_t b57_open(const char *name, uint32 flags, void **cookie);
+static status_t b57_close(void *cookie);
+static status_t b57_free(void *cookie);
+static status_t b57_ioctl(void *cookie,uint32 op,void *data,size_t len);
+static status_t b57_read(void *cookie,off_t pos,void *data,size_t *numBytes);
+static status_t b57_write(void *cookie,off_t pos,const void *data,size_t *numBytes);
+static int32 b57_interrupt(void *cookie);
+static int32 tx_cleanup_thread(void *us);
 
 device_hooks b57_hooks = {b57_open,b57_close,b57_free,b57_ioctl,b57_read,b57_write,NULL,NULL,NULL,NULL};
 
diff --git a/src/add-ons/kernel/partitioning_systems/session/Disc.cpp b/src/add-ons/kernel/partitioning_systems/session/Disc.cpp
index ac16a488be..282474c678 100644
--- a/src/add-ons/kernel/partitioning_systems/session/Disc.cpp
+++ b/src/add-ons/kernel/partitioning_systems/session/Disc.cpp
@@ -255,7 +255,7 @@ List::Last() const {
 
 /*! \brief Creates an unitialized session object
 */
-session::session(uint32 index, session *next = NULL)
+session::session(uint32 index, session *next)
 	: list_item(index, next)
 	, first_track_hint(-1)
 	, last_track_hint(-1)
diff --git a/src/bin/rmattr.cpp b/src/bin/rmattr.cpp
index 2e2a44eae8..af95e54be5 100644
--- a/src/bin/rmattr.cpp
+++ b/src/bin/rmattr.cpp
@@ -63,7 +63,7 @@ remove_attribute(int fd, const char* attribute, bool isPattern)
 	memset(&glob, 0, sizeof(glob_t));
 
 	glob.gl_closedir = (void (*)(void *))fs_close_attr_dir;
-	glob.gl_readdir = fs_read_attr_dir;
+	glob.gl_readdir = (dirent* (*)(void*))fs_read_attr_dir;
 	glob.gl_opendir = open_attr_dir;
 	glob.gl_lstat = stat_attr;
 	glob.gl_stat = stat_attr;
diff --git a/src/bin/rmindex.cpp b/src/bin/rmindex.cpp
index 1bc0d64714..fc79914bf4 100644
--- a/src/bin/rmindex.cpp
+++ b/src/bin/rmindex.cpp
@@ -143,7 +143,7 @@ remove_indices(dev_t device, const char* indexPattern, bool verbose)
 	memset(&glob, 0, sizeof(glob_t));
 
 	glob.gl_closedir = (void (*)(void *))fs_close_index_dir;
-	glob.gl_readdir = fs_read_index_dir;
+	glob.gl_readdir = (dirent *(*)(void *))fs_read_index_dir;
 	glob.gl_opendir = open_index_dir;
 	glob.gl_lstat = stat_index;
 	glob.gl_stat = stat_index;