diff --git a/Makefile b/Makefile
index 70c8a89..9c128de 100644
--- a/Makefile
+++ b/Makefile
@@ -153,8 +153,15 @@ WXVERSION=2.8
 
 endif
 
+#
+# FreeBSD rules. Tested on 12.1.
+#
 ifeq (${OS},FreeBSD)
 
+# Readline and Wxwidgets are installed under /usr/local on Freebsd
+COMMON_CXXFLAGS=-I/usr/local/include
+COMMON_LDFLAGS=-L/usr/local/lib
+
 # This is only needed for bossash, but we can't add it to BOSSASH_LIBS here
 # because that one is redefined later.
 COMMON_SRCS+=PosixSerialPort.cpp BSDPortFactory.cpp
diff --git a/src/BossaWindow.cpp b/src/BossaWindow.cpp
index 9b453e6..81a46ce 100644
--- a/src/BossaWindow.cpp
+++ b/src/BossaWindow.cpp
@@ -279,10 +279,12 @@ BossaWindow::OnSerial(wxCommandEvent& event)
     Samba& samba = wxGetApp().samba;
 
     wxString port = _portComboBox->GetString(event.GetSelection());
+    errno = 0;
+
     if (!samba.connect(portFactory.create(std::string(port.mb_str()))))
     {
         Disconnected();
-        Error(wxString::Format(_("Could not connect to device on %s"), port.c_str()));
+        Error(wxString::Format(_("Could not connect to device on %s: %s"), port.c_str(), strerror(errno)));
         return;
     }
 
diff --git a/src/EefcFlash.cpp b/src/EefcFlash.cpp
index cf44724..c8d62c1 100644
--- a/src/EefcFlash.cpp
+++ b/src/EefcFlash.cpp
@@ -276,7 +276,23 @@ EefcFlash::writePage(uint32_t page)
     _wordCopy.setDstAddr(_addr + page * _size);
     _wordCopy.setSrcAddr(_onBufferA ? _pageBufferA : _pageBufferB);
     _onBufferA = !_onBufferA;
-    waitFSR();
+    // Some chip families have page restrictions on calling EEFC_FCMD_EWP on all pages
+    // e.g. 16K boundary on SAM4S
+    // Print a warning indicating that the flash must be erased first
+    try
+    {
+        waitFSR();
+    }
+    catch (FlashCmdError& exc)
+    {
+        if (page > 0)
+        {
+            printf("\nNOTE: Some chip families may not support auto-erase on all flash regions.\n");
+            printf("      Try erasing the flash first (bossash), or erasing at the same time (bossac).");
+            fflush(stdout);
+        }
+        throw;
+    }
     _wordCopy.runv();
     if (_planes == 2 && page >= _pages / 2)
         writeFCR1(_eraseAuto ? EEFC_FCMD_EWP : EEFC_FCMD_WP, page - _pages / 2);
diff --git a/src/PosixSerialPort.cpp b/src/PosixSerialPort.cpp
index 45eaca9..ccd9848 100644
--- a/src/PosixSerialPort.cpp
+++ b/src/PosixSerialPort.cpp
@@ -32,9 +32,7 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <fcntl.h>
-#include <errno.h>
 #include <termios.h>
-#include <errno.h>
 #include <sys/ioctl.h>
 
 #include <string>
@@ -290,10 +288,7 @@ PosixSerialPort::put(int c)
 void
 PosixSerialPort::flush()
 {
-    // There isn't a reliable way to flush on a file descriptor
-    // so we just wait it out.  One millisecond is the USB poll
-    // interval so that should cover it.
-    usleep(1000);
+    tcdrain(_devfd);
 }
 
 bool