diff --git a/SConstruct b/SConstruct
index 246cdf7..e58e9ac 100644
--- a/SConstruct
+++ b/SConstruct
@@ -81,7 +81,7 @@ def InstallPerm(env, dest, files, perm):
     obj = env.Install(dest, files)
     for i in obj:
         env.AddPostAction(i, Chmod(str(i), perm))
-    return dest
+    return obj
 
 
 env = Environment(tools = ['default', 'textfile'])
diff --git a/include/ucore/mbuf.h b/include/ucore/mbuf.h
index 1b92b81..bcd551d 100644
--- a/include/ucore/mbuf.h
+++ b/include/ucore/mbuf.h
@@ -151,7 +151,7 @@ static UC_INLINE uint32_t uc_mbuf_tailroom(struct MBuf *mbuf)
 /**
  * @return the length of the headroom in this mbuf
  */
-static inline uint32_t uc_mbuf_headroom(struct MBuf *mbuf)
+static UC_INLINE uint32_t uc_mbuf_headroom(struct MBuf *mbuf)
 {
     return (uint32_t)(mbuf->head - mbuf->bufstart);
 }
@@ -187,6 +187,25 @@ uint8_t *uc_mbuf_push(struct MBuf *mbuf, uint32_t size);
  **/
 uint8_t *uc_mbuf_pull(struct MBuf *mbuf, uint32_t size);
 
+/** Add more tailroom to an mbuf.
+ * Can only be done with mbufs with either 
+ * UC_MBUF_FL_MALLOC or UC_MBUF_FL_MALLOC_BUF.
+ *
+ * @param len additional tailroom to add to mbuf
+ * @return 0 on success, otherwise failure
+ *
+ */
+int uc_mbuf_extend_tailroom(struct MBuf *mbuf, uint32_t len);
+
+/** Get a pointer to the data of the buffer
+ * 
+ * @return pointer to the start of the data (head)
+ */
+static UC_INLINE uint8_t *uc_mbuf_head(struct MBuf* mbuf)
+{
+    return mbuf->head;
+}
+
 #undef UC_INLINE
 
 #endif
diff --git a/include/ucore/string.h b/include/ucore/string.h
index fa586bb..6865403 100644
--- a/include/ucore/string.h
+++ b/include/ucore/string.h
@@ -77,11 +77,15 @@ int
 getfields(char *str, char **args, int max, int mflag, const char *set);
 
 //Converts bytes to a human representable test, (i.e. 12kB, 160 MB 1.78 GB etc.)
-//Conversion is done in decimal (base 10 ,1 kB == 1000 bytes)
 ///result should be at least of size 12,
 ///returns the result argument
 char *
-uc_human_bytesz(uint64_t bytes, char *result, size_t result_len);
+uc_human_bytesz_dec(uint64_t bytes, char *result, size_t result_len);
+
+//same as uc_human_bytesz_bin, but Conversion is done in binary 
+//(base 2 ,1 KiB == 1024 bytes)
+char *
+uc_human_bytesz_bin(uint64_t bytes, char *result, size_t result_len);
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/ucore/utils.h b/include/ucore/utils.h
index e70327c..0b2e358 100644
--- a/include/ucore/utils.h
+++ b/include/ucore/utils.h
@@ -94,7 +94,7 @@ const typeof( ((const type *)0)->member ) *__mptr = (ptr);    \
         fflush(stdout);\
     } while(0)
 #else
-    #define TRACEF(fmt, ...)
+    #define TRACEF(fmt, ...) do {} while(0)
 #endif
 
 /** 
diff --git a/src/human_bytesz.c b/src/human_bytesz.c
index 00edcb4..ab8f658 100644
--- a/src/human_bytesz.c
+++ b/src/human_bytesz.c
@@ -3,7 +3,7 @@
 #include "ucore/string.h"
 
 char *
-uc_human_bytesz(uint64_t bytes, char *result, size_t result_len)
+uc_human_bytesz_dec(uint64_t bytes, char *result, size_t result_len)
 {
     if (bytes < 1000) {
         snprintf(result, result_len, "%" PRIu64 " b", bytes);
@@ -22,3 +22,22 @@ uc_human_bytesz(uint64_t bytes, char *result, size_t result_len)
     return result;
 }
 
+char *
+uc_human_bytesz_bin(uint64_t bytes, char *result, size_t result_len)
+{
+    if (bytes < 1024) {
+        snprintf(result, result_len, "%" PRIu64 " b", bytes);
+    } else if (bytes < 1048576) {
+        snprintf(result, result_len, "%.2f KiB", bytes/1024.0);
+    } else if (bytes < 1073741824ULL) {
+        snprintf(result, result_len, "%.2f MiB", bytes/1048576.0);
+    } else if (bytes < 1099511627776ULL) {
+        snprintf(result, result_len, "%.2f GiB", bytes/1073741824.0);
+    } else if (bytes < 1125899906842624ULL) {
+        snprintf(result, result_len, "%.2f TiB", bytes/1099511627776.0);
+    } else {
+        snprintf(result, result_len, "%.2f PiB", bytes/1125899906842624.0);
+    }
+
+    return result;
+}
diff --git a/src/mbuf.c b/src/mbuf.c
index 865612a..390630f 100644
--- a/src/mbuf.c
+++ b/src/mbuf.c
@@ -1,4 +1,5 @@
 #include <string.h>
+#include <assert.h>
 #include <stdlib.h>
 #include "ucore/mbuf.h"
 
@@ -119,3 +120,81 @@ struct MBuf *uc_mbuf_copy_data(struct MBuf *mbuf)
     return copy;
 }
 
+int uc_mbuf_extend_tailroom(struct MBuf *mbuf, uint32_t len)
+{
+    uint32_t tot_len;
+    uint32_t headroom_len;
+    uint32_t data_len;
+    uint32_t tailroom_len;
+    uint8_t *new_data;
+    uint32_t p1_off = 0;
+    uint32_t p2_off = 0;
+    uint32_t p3_off = 0;
+    uint32_t p4_off = 0;
+
+    if ((mbuf->flags & (UC_MBUF_FL_MALLOC | UC_MBUF_FL_MALLOC_BUF)) == 0) {
+        return -1;
+    }
+    
+    headroom_len = uc_mbuf_headroom(mbuf);
+    data_len     = uc_mbuf_len(mbuf);
+    tailroom_len = uc_mbuf_tailroom(mbuf);
+    tot_len = headroom_len +
+                  data_len     +
+                  tailroom_len;
+
+    if (tot_len + len < tot_len) {
+        //overflowed
+        return -2;
+    }
+    
+    tot_len += len;
+    
+    //need to re-adjust p1-p4 after the realloc
+    //This assumes the user controlled p1-p4 really are
+    //set to point into the data, but we document they have
+    //to be.
+    if (mbuf->p1 != NULL) {
+        p1_off = (uint32_t)(mbuf->p1 - mbuf->bufstart);
+    }
+    if (mbuf->p2 != NULL) {
+        p2_off = (uint32_t)(mbuf->p2 - mbuf->bufstart);
+    }
+    if (mbuf->p3 != NULL) {
+        p3_off = (uint32_t)(mbuf->p3 - mbuf->bufstart);
+    }
+    if (mbuf->p4 != NULL) {
+        p4_off = (uint32_t)(mbuf->p4 - mbuf->bufstart);
+    }
+
+    assert(tot_len >= mbuf->allocated);
+
+    new_data = realloc(mbuf->bufstart, tot_len);
+    if (new_data == NULL) {
+        return -3;
+    }
+
+    mbuf->allocated = tot_len;
+    mbuf->bufstart = new_data;
+    mbuf->head = mbuf->bufstart + headroom_len;
+    mbuf->tail = mbuf->bufstart + headroom_len + data_len;
+
+    assert(uc_mbuf_len(mbuf) == data_len);
+    assert(uc_mbuf_tailroom(mbuf) >= tailroom_len);
+
+    if (mbuf->p1 != NULL) {
+        mbuf->p1 = mbuf->bufstart + p1_off;
+    }
+    if (mbuf->p2 != NULL) {
+        mbuf->p2 = mbuf->bufstart + p2_off;
+    }
+    if (mbuf->p3 != NULL) {
+        mbuf->p3 = mbuf->bufstart + p3_off;
+    }
+    if (mbuf->p4 != NULL) {
+        mbuf->p4 = mbuf->bufstart + p4_off;
+    }
+
+    return 0;
+
+}
diff --git a/test/SConscript b/test/SConscript
index fe318d9..074db11 100644
--- a/test/SConscript
+++ b/test/SConscript
@@ -21,7 +21,7 @@ tests = test_env.Glob('test_*.c')
 test_executable = 'test_runner'
 #run test_runner --xml to produce an xml result file
 if test_xml:
-    test_executable += ' --xml'
+    test_executable += ' -x'
 
 prog = test_env.Program('test_runner', tests)
 cmd  = test_env.Command(target='test_phony' , 
diff --git a/test/test_human_bytesz.c b/test/test_human_bytesz.c
index c3819d9..9a1d760 100644
--- a/test/test_human_bytesz.c
+++ b/test/test_human_bytesz.c
@@ -6,7 +6,11 @@ START_TEST (test_human_bytesz_bytes)
     char result[128];
     char *rc;
 
-    rc = uc_human_bytesz(999, result, sizeof result);
+    rc = uc_human_bytesz_dec(999, result, sizeof result);
+    fail_if(rc == NULL);
+    ck_assert_str_eq(result, "999 b");
+
+    rc = uc_human_bytesz_bin(999, result, sizeof result);
     fail_if(rc == NULL);
     ck_assert_str_eq(result, "999 b");
 END_TEST
@@ -15,7 +19,11 @@ START_TEST (test_human_bytesz_bytes_0)
     char result[128];
     char *rc;
 
-    rc = uc_human_bytesz(0, result, sizeof result);
+    rc = uc_human_bytesz_dec(0, result, sizeof result);
+    fail_if(rc == NULL);
+    ck_assert_str_eq(result, "0 b");
+
+    rc = uc_human_bytesz_bin(0, result, sizeof result);
     fail_if(rc == NULL);
     ck_assert_str_eq(result, "0 b");
 END_TEST
@@ -24,45 +32,65 @@ START_TEST (test_human_bytesz_kilobytes)
     char result[128];
     char *rc;
 
-    rc = uc_human_bytesz(64000, result, sizeof result);
+    rc = uc_human_bytesz_dec(64000, result, sizeof result);
     fail_if(rc == NULL);
     ck_assert_str_eq(result, "64.00 kB");
+
+    rc = uc_human_bytesz_bin(64000, result, sizeof result);
+    fail_if(rc == NULL);
+    ck_assert_str_eq(result, "62.50 KiB");
 END_TEST
 
 START_TEST (test_human_bytesz_megabytes)
     char result[128];
     char *rc;
 
-    rc = uc_human_bytesz(6409000, result, sizeof result);
+    rc = uc_human_bytesz_dec(6409000, result, sizeof result);
     fail_if(rc == NULL);
     ck_assert_str_eq(result, "6.41 MB");
+
+    rc = uc_human_bytesz_bin(6409000, result, sizeof result);
+    fail_if(rc == NULL);
+    ck_assert_str_eq(result, "6.11 MiB");
 END_TEST
 
 START_TEST (test_human_bytesz_gigabytes)
     char result[128];
     char *rc;
 
-    rc = uc_human_bytesz(126999400000, result, sizeof result);
+    rc = uc_human_bytesz_dec(126999400000, result, sizeof result);
     fail_if(rc == NULL);
     ck_assert_str_eq(result, "127.00 GB");
+
+    rc = uc_human_bytesz_bin(126999400000, result, sizeof result);
+    fail_if(rc == NULL);
+    ck_assert_str_eq(result, "118.28 GiB");
 END_TEST
 
 START_TEST (test_human_bytesz_terrabytes)
     char result[128];
     char *rc;
 
-    rc = uc_human_bytesz(12453400030000, result, sizeof result);
+    rc = uc_human_bytesz_dec(12453400030000, result, sizeof result);
     fail_if(rc == NULL);
     ck_assert_str_eq(result, "12.45 TB");
+
+    rc = uc_human_bytesz_bin(12453400030000, result, sizeof result);
+    fail_if(rc == NULL);
+    ck_assert_str_eq(result, "11.33 TiB");
 END_TEST
 
 START_TEST (test_human_bytesz_petabytes)
     char result[128];
     char *rc;
 
-    rc = uc_human_bytesz(~0LL, result, sizeof result);
+    rc = uc_human_bytesz_dec(~0LL, result, sizeof result);
     fail_if(rc == NULL);
     ck_assert_str_eq(result, "18446.74 PB");
+
+    rc = uc_human_bytesz_bin(~0ULL, result, sizeof result);
+    fail_if(rc == NULL);
+    ck_assert_str_eq(result, "16384.00 PiB");
 END_TEST
 
 
diff --git a/test/test_mbuf.c b/test/test_mbuf.c
index dfe8577..453ffc8 100644
--- a/test/test_mbuf.c
+++ b/test/test_mbuf.c
@@ -1,5 +1,6 @@
 #include <check.h>
 #include <string.h>
+#include <stdlib.h>
 #include <ucore/mbuf.h>
 
 
@@ -191,7 +192,7 @@ START_TEST (test_mbuf_copy)
     fail_if(copy == NULL);
     fail_if(uc_mbuf_len(copy) != 10);
     fail_if(uc_mbuf_headroom(copy) != 5);
-    fail_if(memcmp(mbuf->head, copy->head, 10) != 0);
+    fail_if(memcmp(uc_mbuf_head(mbuf), uc_mbuf_head(copy), 10) != 0);
 
     uc_mbuf_free(mbuf);
     uc_mbuf_free(copy);
@@ -211,7 +212,7 @@ START_TEST (test_mbuf_zero)
     strcpy((char*)data1, "123456789");
     uc_mbuf_zero(mbuf);
 
-    fail_if(memcmp(mbuf->head, "\0\0\0\0\0\0\0\0\0\0", 10) != 0);
+    fail_if(memcmp(uc_mbuf_head(mbuf), "\0\0\0\0\0\0\0\0\0\0", 10) != 0);
 
     uc_mbuf_free(mbuf);
 
@@ -240,6 +241,55 @@ START_TEST (test_mbuf_static)
 
 END_TEST
 
+START_TEST (test_mbuf_extend_tailroom)
+    struct MBuf *mbuf;
+    uint8_t *data;
+    void *filler;
+    int rc;
+    
+    mbuf = uc_mbuf_new_hr(5,2);
+    fail_if(mbuf == NULL);
+
+    data = uc_mbuf_put(mbuf, 5);
+    fail_if(data == NULL);
+    memcpy((char*)data, "hello", 5);
+    mbuf->p1 = mbuf->tail;
+
+    data = uc_mbuf_put(mbuf, 6);
+    fail_if(data != NULL);
+
+    filler = malloc(5); //just a hope, so realloc also moves..
+    rc = uc_mbuf_extend_tailroom(mbuf, 1024);
+    ck_assert_int_eq(rc, 0);
+    ck_assert_int_eq(uc_mbuf_tailroom(mbuf), 1024);
+    ck_assert_int_eq(uc_mbuf_headroom(mbuf), 2);
+    ck_assert_int_eq(uc_mbuf_len(mbuf), 5);
+
+    //should work now
+    data = uc_mbuf_put(mbuf, 6);
+    fail_if(data == NULL);
+    strcpy((char*)data, "world");
+    ck_assert_str_eq((const char*)mbuf->head, "helloworld");
+    ck_assert_str_eq((const char*)mbuf->p1, "world");
+
+    uc_mbuf_free(mbuf);
+    free(filler);
+
+END_TEST
+
+START_TEST (test_mbuf_extend_tailroom_wrong_type)
+    struct MBuf *mbuf;
+    int rc;
+    
+    mbuf = uc_mbuf_new_inline(10);
+    fail_if(mbuf == NULL);
+
+    rc = uc_mbuf_extend_tailroom(mbuf, 1024);
+    ck_assert_int_ne(rc, 0);
+
+    uc_mbuf_free(mbuf);
+
+END_TEST
 
 
 Suite *mbuf_suite(void)
@@ -258,6 +308,8 @@ Suite *mbuf_suite(void)
     tcase_add_test(tc, test_mbuf_copy);
     tcase_add_test(tc, test_mbuf_zero);
     tcase_add_test(tc, test_mbuf_static);
+    tcase_add_test(tc, test_mbuf_extend_tailroom);
+    tcase_add_test(tc, test_mbuf_extend_tailroom_wrong_type);
 
     suite_add_tcase(s, tc);
 
diff --git a/test/test_runner.c b/test/test_runner.c
index c485f6f..a797d5f 100644
--- a/test/test_runner.c
+++ b/test/test_runner.c
@@ -2,6 +2,7 @@
 #include <getopt.h>
 #include <stdio.h>
 #include <check.h>
+#include <getopt.h>
 
 
 typedef Suite *(*suite_func)(void);
@@ -53,7 +54,24 @@ static suite_func suites[] = {
 int
 main (int argc, char *argv[])
 {
-    int xml_output = argc > 1 && strcmp(argv[1], "--xml") == 0;
+    int xml_output = 0;
+    int c;
+    const char *test_case = NULL;
+
+    while ((c = getopt(argc, argv, "xk:")) != -1) {
+        switch (c) {
+            case 'x':
+                xml_output = 1;
+                break;
+            case 'k':
+                test_case = optarg;
+                break;
+            default:
+                printf("Ignoring unknown option %c\n", c);
+                break;
+        }
+    }
+
 
     int number_failed = 0;
     size_t i;
@@ -69,7 +87,12 @@ main (int argc, char *argv[])
         srunner_add_suite(sr, suites[i]());
     }
 
-    srunner_run_all (sr, CK_VERBOSE);
+    if (test_case == NULL) {
+        srunner_run_all (sr, CK_VERBOSE);
+    } else {
+        printf("Running %s only\n", test_case);
+        srunner_run(sr, NULL, test_case, CK_VERBOSE);
+    }
     number_failed = srunner_ntests_failed (sr);
     srunner_free (sr);
     
diff --git a/test/test_timers.c b/test/test_timers.c
index 33c0b09..b6cdf5f 100644
--- a/test/test_timers.c
+++ b/test/test_timers.c
@@ -62,7 +62,7 @@ START_TEST (test_timers_simple)
     rc = uc_timers_run(&timers);
     fail_if(rc != 0);
     fail_if(tt.cnt != 0);
-    fail_if(uc_timers_count(&timers) != 1);
+    ck_assert_int_eq(uc_timers_count(&timers), 1);
 
     //10 seconds into the future, our timer should fire
     t += 5;
@@ -77,7 +77,7 @@ START_TEST (test_timers_simple)
     rc = uc_timers_run(&timers);
     fail_if(rc != 0);
     fail_if(tt.cnt != 1);
-    fail_if(uc_timers_count(&timers) != 0);
+    ck_assert_int_eq(uc_timers_count(&timers), 0);
     fail_if(uc_timer_running(&timer) != 0);
 
 END_TEST
@@ -112,7 +112,7 @@ START_TEST (test_timers_add_from_callback)
     fail_if(tt.cnt != 2);
 
     fail_if(uc_timer_running(&timer) == 0);
-    fail_if(uc_timers_count(&timers) != 1);
+    ck_assert_int_eq(uc_timers_count(&timers), 1);
 
 END_TEST
 
@@ -136,7 +136,7 @@ START_TEST (test_timers_remove_from_callback)
     uc_timers_add(&timers, &timer, 5, 0);
     uc_timers_add(&timers, &timer2, 10, 0);
 
-    fail_if(uc_timers_count(&timers) != 2);
+    ck_assert_int_eq(uc_timers_count(&timers), 2);
     rc = uc_timers_first(&timers, &tv);
     fail_if(rc != 0);
     fail_if(tv.tv_sec != TEST_TIMER_START + 5);
@@ -152,7 +152,7 @@ START_TEST (test_timers_remove_from_callback)
     //and our timer2 should be removed, and timer has fired so it
     //should be removed too
 
-    fail_if(uc_timers_count(&timers) != 0);
+    ck_assert_int_eq(uc_timers_count(&timers), 0);
     fail_if(uc_timer_running(&timer) != 0);
     fail_if(uc_timer_running(&timer2) != 0);
     rc = uc_timers_first(&timers, &tv);
@@ -183,14 +183,14 @@ START_TEST (test_timers_add_remove)
     fail_if(first.tv_sec != TEST_TIMER_START + 5);
     fail_if(first.tv_usec != 0);
 
-    fail_if(uc_timers_count(&timers) != sizeof timer/sizeof timer[0]);
+    ck_assert_int_eq(uc_timers_count(&timers), sizeof timer/sizeof timer[0]);
 
     for (i = 0; i < sizeof timer/sizeof timer[0]; i++) {
         uc_timers_remove(&timers, &timer[i]);
     }
 
 
-    fail_if(uc_timers_count(&timers) != 0);
+    ck_assert_int_eq(uc_timers_count(&timers), 0);
     fail_if(uc_timers_first(&timers, &first) == 0);
 
 END_TEST