Merge branch 'master' of git.cryptech.is.:sw/stm32

6 files changed, 444 insertions, 153 deletions

diff --git a/projects/hsm/cryptech_miniterm b/projects/hsm/cryptech_miniterm
new file mode 100755
index 0000000..b8ea3b1
--- /dev/null
+++ b/projects/hsm/cryptech_miniterm
@@ -0,0 +1,45 @@
+#!/usr/bin/env python
+#
+# Copyright (c) 2016, NORDUnet A/S All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+# - Redistributions of source code must retain the above copyright notice,
+#   this list of conditions and the following disclaimer.
+#
+# - Redistributions in binary form must reproduce the above copyright
+#   notice, this list of conditions and the following disclaimer in the
+#   documentation and/or other materials provided with the distribution.
+#
+# - Neither the name of the NORDUnet nor the names of its contributors may
+#   be used to endorse or promote products derived from this software
+#   without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+# IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+# TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""
+Utility to run PySerial's "miniterm" with default settings suitable
+for talking to the Cryptech Alpha's console port.
+"""
+
+import serial.tools.miniterm
+import sys
+import os
+
+default_port = os.getenv("CRYPTECH_CTY_CLIENT_SERIAL_DEVICE")
+default_baud = os.getenv("CRYPTECH_CTY_CLIENT_SERIAL_SPEED", 921600)
+
+sys.exit(serial.tools.miniterm.main(default_port     = default_port, 
+                                    default_baudrate = int(default_baud)))
+
diff --git a/projects/hsm/cryptech_probe b/projects/hsm/cryptech_probe
new file mode 100755
index 0000000..14dae01
--- /dev/null
+++ b/projects/hsm/cryptech_probe
@@ -0,0 +1,145 @@
+#!/usr/bin/env python
+#
+# Copyright (c) 2016, NORDUnet A/S All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+# - Redistributions of source code must retain the above copyright notice,
+#   this list of conditions and the following disclaimer.
+#
+# - Redistributions in binary form must reproduce the above copyright
+#   notice, this list of conditions and the following disclaimer in the
+#   documentation and/or other materials provided with the distribution.
+#
+# - Neither the name of the NORDUnet nor the names of its contributors may
+#   be used to endorse or promote products derived from this software
+#   without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+# IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+# TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""
+Utility to probe USB serial port(s) trying to figure out which one(s)
+we have plugged in today.  stdout is environment variable settings,
+suitable for use in bash with "eval `cryptech_probe`"; all other output
+goes to stderr.
+"""
+
+import sys
+import time
+import argparse
+import serial.tools.list_ports_posix
+
+class positive_integer(int):
+    def __init__(self, value):
+        if self <= 0:
+            raise ValueError
+
+parser = argparse.ArgumentParser(formatter_class = argparse.ArgumentDefaultsHelpFormatter)
+parser.add_argument("-v", "--verbose",    action = "store_true",   help = "produce human-readable output")
+parser.add_argument("-d", "--debug",      action = "store_true",   help = "blather about what we're doing")
+parser.add_argument("--no-cleanup",       action = "store_true",   help = "don't send cleanup sequences after probing")
+parser.add_argument("--read-buffer-size", type = positive_integer, help = "size of read buffer", default = 1024)
+args = parser.parse_args()
+
+SLIP_END     = chr(0300)        # Indicates end of SLIP packet
+SLIP_ESC     = chr(0333)        # Indicates byte stuffing
+SLIP_ESC_END = chr(0334)        # ESC ESC_END means END data byte
+SLIP_ESC_ESC = chr(0335)        # ESC ESC_ESC means ESC data byte
+
+Control_U    = chr(0025)        # Console: clear line
+Control_M    = chr(0015)        # Console: end of line
+
+RPC_query    = chr(0) * 8       # client_handle = 0, function code = RPC_FUNC_GET_VERSION
+RPC_reply    = chr(0) * 12      # opcode = RPC_FUNC_GET_VERSION, client_handle = 0, valret = HAL_OK
+
+# This is the query string we send to each USB port we find.  It's
+# intended to be relatively harmless, at least for either of the HSM
+# ports: the final Control-U should prevent the console from trying to
+# interpret the RPC command, and the SLIP_END markers should cause
+# the RPC server to treat the ASCII control characters as noise.
+#
+# Yes, this is a total kludge.  Useful identifiers for the USB ports
+# are are on the wish list for a future revision of the hardware, but
+# for the moment, we do what we can with what we have.
+
+probe_string = SLIP_END + Control_U + SLIP_END + RPC_query + SLIP_END + Control_U + Control_M
+
+ports = [port for port, desc, hwid in serial.tools.list_ports_posix.comports()
+         if "VID:PID=0403:6014" in hwid]
+
+if not ports:
+    sys.exit("Couldn't find any likely USB ports")
+
+if args.debug:
+    sys.stderr.write("Candidate USB ports: {}\n".format(", ".join(ports)))
+
+env = {}
+
+for port in ports:
+
+    while True:
+        try:
+            tty = serial.Serial(port, 921600, timeout=0.1)
+            break
+        except serial.SerialException:
+            time.sleep(0.2)
+
+    for c in probe_string:
+        tty.write(c)
+        time.sleep(0.1)
+
+    response = tty.read(args.read_buffer_size)
+    if args.debug:
+        sys.stderr.write("Received from {}: {!r} ({})\n".format(port, response, ":".join("{:02x}".format(ord(c)) for c in response)))
+
+    # Check whether we got a known console prompt.
+
+    is_cty = any(prompt in response for prompt in ("Username:", "Password:", "cryptech>"))
+
+    # Check whether we got something that looks like the response to an RPC version query.
+    # We skip over the version value itself, as it might change, but we check that it's
+    # terminated properly.  This is fragile, and will need to handle SLIP decoding if
+    # we ever bump one of the version fields up into the range where the SLIP control
+    # characters live, but it will do for the moment.
+
+    try:
+        is_hsm = response[response.index(SLIP_END + RPC_reply) + len(SLIP_END + RPC_reply) + 4] == SLIP_END
+    except ValueError:
+        is_hsm = False
+    except IndexError:
+        is_hsm = False
+
+    if is_cty and args.verbose:
+        sys.stderr.write("{} looks like the Cryptech HSM console port\n".format(port))
+
+    if is_hsm and args.verbose:
+        sys.stderr.write("{} looks like the Cryptech HSM RPC port\n".format(port))
+
+    if is_cty:
+        env.update(CRYPTECH_CTY_CLIENT_SERIAL_DEVICE = port)
+
+    if is_hsm:
+        env.update(CRYPTECH_RPC_CLIENT_SERIAL_DEVICE = port)
+
+    if (is_cty or is_hsm) and not args.no_cleanup:
+        if is_cty:
+            tty.write(Control_U)
+        if is_hsm:
+            tty.write(SLIP_END)
+        while tty.read(args.read_buffer_size):
+            pass
+
+    tty.close()
+
+sys.stdout.write("export {}\n".format(" ".join("{}='{}'".format(var, env[var]) for var in sorted(env))))
diff --git a/projects/hsm/cryptech_upload b/projects/hsm/cryptech_upload
index 722e37b..6d6d4f7 100755
--- a/projects/hsm/cryptech_upload
+++ b/projects/hsm/cryptech_upload
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 #
 # Copyright (c) 2016, NORDUnet A/S All rights reserved.
 #
@@ -27,16 +27,21 @@
 # LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
 """
-Utility to upload new a firmware image or FPGA bitstream
+Utility to upload a new firmware image or FPGA bitstream.
 """
+
 import os
 import sys
 import time
 import struct
 import serial
-import argparse
 import getpass
+import os.path
+import tarfile
+import argparse
+import platform
 
 from binascii import crc32
 
@@ -48,35 +53,51 @@ def parse_args():
     """
     Parse the command line arguments
     """
-    parser = argparse.ArgumentParser(description = "File uploader",
-                                     add_help = True,
+
+    share_directory = "/usr/share" if platform.system() == "Linux" else "/usr/local/share"
+
+    default_tarball = os.path.join(share_directory, "cryptech-alpha-firmware.tar.gz")
+
+    if not os.path.exists(default_tarball):
+        default_tarball = None
+
+    parser = argparse.ArgumentParser(description = __doc__,
                                      formatter_class = argparse.ArgumentDefaultsHelpFormatter,
                                      )
 
-    parser.add_argument('-d', '--device',
-                        dest='device',
-                        default='/dev/ttyUSB0',
-                        help='Name of management port USB serial device',
+    parser.add_argument("-d", "--device",
+                        default = os.getenv("CRYPTECH_CTY_CLIENT_SERIAL_DEVICE", "/dev/ttyUSB0"),
+                        help = "Name of management port USB serial device",
                         )
 
-    parser.add_argument('--fpga',
-                        dest='fpga',
-                        action='store_true', default=False,
-                        help='Upload FPGA bitstream',
+    parser.add_argument("--firmware-tarball",
+                        type = argparse.FileType("rb"),
+                        default = default_tarball,
+                        help = "Location of firmware tarball",
                         )
-    parser.add_argument('--firmware',
-                        dest='firmware',
-                        action='store_true', default=False,
-                        help='Upload firmware image',
-                        )
-    parser.add_argument('--bootloader',
-                        dest='bootloader',
-                        action='store_true', default=False,
-                        help='Upload bootloader image',
+
+    actions = parser.add_mutually_exclusive_group(required = True)
+    actions.add_argument("--fpga",
+                         action = "store_true",
+                         help = "Upload FPGA bitstream",
+                         )
+    actions.add_argument("--firmware", "--hsm",
+                         action = "store_true",
+                         help = "Upload HSM firmware image",
+                         )
+    actions.add_argument("--bootloader",
+                         action = "store_true",
+                         help = "Upload bootloader image (dangerous!)",
+                         )
+
+    parser.add_argument("--simon-says-whack-my-bootloader",
+                        action = "store_true",
+                        help = "Confirm that you really want to risk bricking the HSM",
                         )
 
-    # positional argument(s)
-    parser.add_argument('filename')
+    parser.add_argument("-i", "--explicit-image",
+                        type = argparse.FileType("rb"),
+                        help = "Explicit source image file for upload, overrides firmware tarball")
 
     return parser.parse_args()
 
@@ -84,13 +105,13 @@ def parse_args():
 def _write(dst, data):
     dst.write(data)
     #if len(data) == 4:
-    #    print("Wrote 0x{!s}".format(data.encode('hex')))
+    #    print("Wrote 0x{!s}".format(data.encode("hex")))
     #else:
     #    print("Wrote {!r}".format(data))
 
 
 def _read(dst):
-    res = ''
+    res = ""
     x = dst.read(1)
     while not x:
         x = dst.read(1)
@@ -104,50 +125,51 @@ pin = None
 
 def _execute(dst, cmd):
     global pin
-    _write(dst, '\r')
+    _write(dst, "\r")
     prompt = _read(dst)
-    if prompt.endswith('Username: '):
-        _write(dst, 'so\r')
+    if prompt.endswith("Username: "):
+        _write(dst, "so\r")
         prompt = _read(dst)
-        if prompt.endswith('Password: '):
+        if prompt.endswith("Password: "):
             if not pin:
-                pin = getpass.getpass('SO PIN: ')
-            _write(dst, pin + '\r')
+                pin = getpass.getpass("SO PIN: ")
+            _write(dst, pin + "\r")
             prompt = _read(dst)
-    if not prompt.endswith('> '):
-        #sys.stderr.write('Device does not seem to be ready for a file transfer (got {!r})\n'.format(prompt))
+    if not prompt.endswith(("> ", "# ")):
+        print("Device does not seem to be ready for a file transfer (got {!r})".format(prompt))
         return prompt
-    _write(dst, cmd + '\r')
+    _write(dst, cmd + "\r")
     response = _read(dst)
     return response
 
-def send_file(filename, args, dst):
-    s = os.stat(filename)
-    size = s.st_size
-    src = open(filename, 'rb')
+def send_file(src, size, args, dst):
     if args.fpga:
         chunk_size = FPGA_CHUNK_SIZE
-        response = _execute(dst, 'fpga bitstream upload')
+        response = _execute(dst, "fpga bitstream upload")
     elif args.firmware:
         chunk_size = FIRMWARE_CHUNK_SIZE
-        response = _execute(dst, 'firmware upload')
-        if 'Rebooting' in response:
-            response = _execute(dst, 'firmware upload')
+        response = _execute(dst, "firmware upload")
+        if "Rebooting" in response:
+            response = _execute(dst, "firmware upload")
     elif args.bootloader:
         chunk_size = FIRMWARE_CHUNK_SIZE
-        response = _execute(dst, 'bootloader upload')
-    if 'Access denied' in response:
-        print 'Access denied'
+        response = _execute(dst, "bootloader upload")
+    if "Access denied" in response:
+        print "Access denied"
         return False
-    if not 'OK' in response:
-        sys.stderr.write('Device did not accept the upload command (got {!r})\n'.format(response))
+    if not "OK" in response:
+        print("Device did not accept the upload command (got {!r})".format(response))
         return False
 
     crc = 0
     counter = 0
     # 1. Write size of file (4 bytes)
-    _write(dst, struct.pack('<I', size))
-    _read(dst)
+    _write(dst, struct.pack("<I", size))
+    response = _read(dst)
+    if not response.startswith("Send "):
+        print response
+        return False
+
     # 2. Write file contents while calculating CRC-32
     while True:
         data = src.read(chunk_size)
@@ -160,13 +182,13 @@ def send_file(filename, args, dst):
             ack_bytes = dst.read(4)
             if len(ack_bytes) == 4:
                 break
-            print('ERROR: Did not receive an ACK, got {!r}'.format(ack_bytes))
-            dst.write('\r')  # eventually get back to the CLI prompt
-        ack = struct.unpack('<I', ack_bytes)[0]
+            print("ERROR: Did not receive an ACK, got {!r}".format(ack_bytes))
+            dst.write("\r")  # eventually get back to the CLI prompt
+        ack = struct.unpack("<I", ack_bytes)[0]
         if ack != counter + 1:
-            print('ERROR: Did not receive the expected counter as ACK (got {!r}/{!r}, not {!r})'.format(ack, ack_bytes, counter))
+            print("ERROR: Did not receive the expected counter as ACK (got {!r}/{!r}, not {!r})".format(ack, ack_bytes, counter))
             flush = dst.read(100)
-            print('FLUSH data: {!r}'.format(flush))
+            print("FLUSH data: {!r}".format(flush))
             return False
         counter += 1
 
@@ -175,35 +197,88 @@ def send_file(filename, args, dst):
     _read(dst)
 
     # 3. Write CRC-32 (4 bytes)
-    _write(dst, struct.pack('<I', crc))
-    _read(dst)
+    _write(dst, struct.pack("<I", crc))
+    response = _read(dst)
+    print response
 
     src.close()
 
     if args.fpga:
         # tell the fpga to read its new configuration
-        _execute(dst, 'fpga reset')
+        _execute(dst, "fpga reset")
 
     if args.fpga or args.bootloader:
         # log out of the CLI
         # firmware upgrade reboots, doesn't need an exit
-        _execute(dst, 'exit')
+        _execute(dst, "exit")
 
     return True
 
 
-def main(args):
-    dst = serial.Serial(args.device, 921600, timeout=2)
-    send_file(args.filename, args, dst)
+dire_bootloader_warning = '''
+                            WARNING
+
+Updating the bootloader risks bricking your HSM!  If something goes
+badly wrong here, or you upload a bad bootloader image, you will not
+be able to recover without an ST-LINK programmer.
+
+In most cases a normal "--firmware" upgrade should be all that is
+necessary to bring your HSM up to date, there is seldom any real need
+to update the bootloader.
+
+Do not proceed with this unless you REALLY know what you are doing.
+
+If you got here by accident, ^C now, without answering the PIN prompt.
+'''
+
+
+def main():
+    args = parse_args()
+
+    if args.bootloader and not args.simon_says_whack_my_bootloader:
+        sys.exit("You didn't say \"Simon says\"")
+
+    if args.bootloader:
+        print dire_bootloader_warning
+
+    if args.explicit_image is None and args.firmware_tarball is None:
+        sys.exit("No source file specified for upload and firmware tarball not found")
+
+    if args.explicit_image:
+        src = args.explicit_image       # file-like object, thanks to argparse
+        size = os.fstat(src.fileno()).st_size
+        if size == 0:                   # Flashing from stdin won't work, sorry
+            sys.exit("Can't flash from a pipe or zero-length file")
+        print "Uploading from explicitly-specified file {}".format(args.explicit_image.name)
+
+    else:
+        tar = tarfile.open(fileobj = args.firmware_tarball)
+        print "Firmware tarball {} content:".format(args.firmware_tarball.name)
+        tar.list(True)
+        if args.fpga:
+            name = "alpha_fmc.bit"
+        elif args.firmware:
+            name = "hsm.bin"
+        elif args.bootloader:
+            name = "bootloader.bin"
+        else:
+            # Somebody updated other part of this script without updating this part :(
+            sys.exit("Don't know which component to select from firmware tarball, sorry")
+        try:
+            size = tar.getmember(name).size
+        except KeyError:
+            sys.exit("Expected component {} missing from firmware tarball {}".format(name, args.firmware_tarball.name))
+        src = tar.extractfile(name)
+        print "Uploading {} from {}".format(name, args.firmware_tarball.name)
+
+    print "Initializing serial port and synchronizing with HSM, this may take a few seconds"
+    dst  = serial.Serial(args.device, 921600, timeout = 2)
+    send_file(src, size, args, dst)
     dst.close()
-    return True
 
-if __name__ == '__main__':
+
+if __name__ == "__main__":
     try:
-        args = parse_args()
-        if main(args):
-            sys.exit(0)
-        sys.exit(1)
+        main()
     except KeyboardInterrupt:
         pass
-
diff --git a/projects/hsm/hsm.c b/projects/hsm/hsm.c
index 5758f05..3186bc5 100644
--- a/projects/hsm/hsm.c
+++ b/projects/hsm/hsm.c
@@ -1,7 +1,7 @@
 /*
- * rpc_server.c
- * ------------
- * Remote procedure call server-side private API implementation.
+ * hsm.c
+ * ----------------
+ * Main module for the HSM project.
  *
  * Copyright (c) 2016, NORDUnet A/S All rights reserved.
  *
@@ -33,20 +33,17 @@
  */
 
 /*
- * This is the main RPC server moddule. It creates a new thread to deal
- * with each request, to prevent a long-running request (e.g. RSA keygen)
- * from blocking independent requests from other clients. This has a
- * number of consequences. We can't do a blocking receive in the main
- * thread, because that prevents the dispatch thread from transmitting the
- * response (because they both want to lock the UART - see
- * stm32f4xx_hal_uart.c). So we have to do a non-blocking receive with a
- * callback routine. But we can't create a thread from the callback
- * routine, because it's in the context of an ISR, so we raise a semaphore
- * for the main thread to create the dispatch thread.
+ * This is the main RPC server module. At the moment, it has a single
+ * worker thread to handle RPC requests, while the main thread handles CLI
+ * activity. The design allows for multiple worker threads to handle
+ * concurrent RPC requests from multiple clients (muxed through a daemon
+ * on the host).
  */
 
 #include <string.h>
 
+/* Rename both CMSIS HAL_OK and libhal HAL_OK to disambiguate */
+#define HAL_OK CMSIS_HAL_OK
 #include "cmsis_os.h"
 
 #include "stm-init.h"
@@ -57,46 +54,44 @@
 
 #include "mgmt-cli.h"
 
-/* stm32f4xx_hal_def.h and hal.h both define HAL_OK as an enum value */
-#define HAL_OK HAL_OKAY
-
+#undef HAL_OK
+#define HAL_OK LIBHAL_OK
 #include "hal.h"
 #include "hal_internal.h"
 #include "slip_internal.h"
 #include "xdr_internal.h"
-
-/* RPC buffers. For each active RPC, there will be two - input and output.
- */
+#undef HAL_OK
 
 #ifndef NUM_RPC_TASK
-/* An arbitrary number, but we don't expect to have more than 8 concurrent
- * RPC requests.
+/* Just one RPC task for now. More will require active resource management
+ * of at least the FPGA cores.
  */
-#define NUM_RPC_TASK 8
+#define NUM_RPC_TASK 1
 #endif
 
 #ifndef TASK_STACK_SIZE
 /* Define an absurdly large task stack, because some pkey operation use a
- * lot of stack variables.
+ * lot of stack variables. This has to go in SDRAM, because it exceeds the
+ * total RAM on the ARM.
  */
 #define TASK_STACK_SIZE 200*1024
 #endif
 
 #ifndef MAX_PKT_SIZE
-/* Another arbitrary number, more or less driven by the 4096-bit RSA
+/* An arbitrary number, more or less driven by the 4096-bit RSA
  * keygen test.
  */
 #define MAX_PKT_SIZE 4096
 #endif
 
-/* The thread entry point takes a single void* argument, so we bundle the
- * packet buffer and length arguments together.
+/* RPC buffers. For each active RPC, there will be two - input and output.
  */
 typedef struct {
     size_t len;
     uint8_t buf[MAX_PKT_SIZE];
 } rpc_buffer_t;
 
+#if NUM_RPC_TASK > 1
 /* A mutex to arbitrate concurrent UART transmits, from RPC responses.
  */
 osMutexId  uart_mutex;
@@ -106,6 +101,7 @@ osMutexDef(uart_mutex);
  */
 osMutexId  dispatch_mutex;
 osMutexDef(dispatch_mutex);
+#endif
 
 /* Semaphore to inform the dispatch thread that there's a new RPC request.
  */
@@ -114,65 +110,97 @@ osSemaphoreDef(rpc_sem);
 
 static volatile uint8_t uart_rx;	/* current character received from UART */
 static rpc_buffer_t * volatile rbuf;	/* current RPC input buffer */
+static volatile int reenable_recv = 1;
 
 /* Callback for HAL_UART_Receive_IT().
+ * With multiple worker threads, we can't do a blocking receive, because
+ * that prevents other threads from sending RPC responses (because they
+ * both want to lock the UART - see stm32f4xx_hal_uart.c). So we have to
+ * do a non-blocking receive with a callback routine.
+ * Even with only one worker thread, context-switching to the CLI thread
+ * causes HAL_UART_Receive to miss input.
  */
 void HAL_UART2_RxCpltCallback(UART_HandleTypeDef *huart)
 {
     int complete;
-    hal_slip_recv_char(rbuf->buf, &rbuf->len, sizeof(rbuf->buf), &complete);
-    if (complete)
-	osSemaphoreRelease(rpc_sem);
 
-    HAL_UART_Receive_IT(huart, (uint8_t *)&uart_rx, 1);
-}
+    if (hal_slip_recv_char(rbuf->buf, &rbuf->len, sizeof(rbuf->buf), &complete) != LIBHAL_OK)
+        Error_Handler();
 
-hal_error_t hal_serial_send_char(uint8_t c)
-{
-    return (uart_send_char(c) == 0) ? HAL_OK : HAL_ERROR_RPC_TRANSPORT;
+    if (complete)
+	if (osSemaphoreRelease(rpc_sem) != osOK)
+            Error_Handler();
+
+    if (HAL_UART_Receive_IT(huart, (uint8_t *)&uart_rx, 1) != CMSIS_HAL_OK)
+        /* We may have collided with a transmit.
+         * Signal the dispatch_thread to try again.
+         */
+        reenable_recv = 1;
 }
 
 hal_error_t hal_serial_recv_char(uint8_t *cp)
 {
     /* return the character from HAL_UART_Receive_IT */
     *cp = uart_rx;
-    return HAL_OK;
+    return LIBHAL_OK;
+}
+
+hal_error_t hal_serial_send_char(uint8_t c)
+{
+    return (uart_send_char2(STM_UART_USER, c) == 0) ? LIBHAL_OK : HAL_ERROR_RPC_TRANSPORT;
 }
 
 /* Thread entry point for the RPC request handler.
  */
-static void dispatch_thread(void const *args)
+void dispatch_thread(void const *args)
 {
     rpc_buffer_t ibuf, obuf;
 
     while (1) {
         memset(&ibuf, 0, sizeof(ibuf));
         memset(&obuf, 0, sizeof(obuf));
+        obuf.len = sizeof(obuf.buf);
 
+#if NUM_RPC_TASK > 1
         /* Wait for access to the uart */
         osMutexWait(dispatch_mutex, osWaitForever);
+#endif
+
+        /* Start receiving, or re-enable after failing in the callback. */
+        if (reenable_recv) {
+            if (HAL_UART_Receive_IT(&huart_user, (uint8_t *)&uart_rx, 1) != CMSIS_HAL_OK)
+                Error_Handler();
+            reenable_recv = 0;
+        }
 
         /* Wait for the complete rpc request */
         rbuf = &ibuf;
         osSemaphoreWait(rpc_sem, osWaitForever);
 
+#if NUM_RPC_TASK > 1
         /* Let the next thread handle the next request */
         osMutexRelease(dispatch_mutex);
         /* Let the next thread take the mutex */
         osThreadYield();
-
-        /* Copy client ID from request to response */
-        memcpy(obuf.buf, ibuf.buf, 4);
-        obuf.len = sizeof(obuf.buf) - 4;
+#endif
 
         /* Process the request */
-        hal_rpc_server_dispatch(ibuf.buf + 4, ibuf.len - 4, obuf.buf + 4, &obuf.len);
+        if (hal_rpc_server_dispatch(ibuf.buf, ibuf.len, obuf.buf, &obuf.len) != LIBHAL_OK)
+            /* If hal_rpc_server_dispatch failed with an XDR error, it
+             * probably means the request packet was garbage. In any case, we
+             * have nothing to transmit.
+             */
+            continue;
 
         /* Send the response */
+#if NUM_RPC_TASK > 1
         osMutexWait(uart_mutex, osWaitForever);
-        hal_error_t ret = hal_rpc_sendto(obuf.buf, obuf.len + 4, NULL);
+#endif
+        hal_error_t ret = hal_rpc_sendto(obuf.buf, obuf.len, NULL);
+#if NUM_RPC_TASK > 1
         osMutexRelease(uart_mutex);
-        if (ret != HAL_OK)
+#endif
+        if (ret != LIBHAL_OK)
             Error_Handler();
     }
 }
@@ -206,16 +234,8 @@ static uint8_t *sdram_malloc(size_t size)
 int main()
 {
     stm_init();
+    uart_set_default(STM_UART_MGMT);
 
-#ifdef TARGET_CRYPTECH_DEV_BRIDGE
-    /* Wait six seconds to not upset the Novena at boot. */
-    led_on(LED_BLUE);
-    for (int i = 0; i < 12; i++) {
-	osDelay(500);
-	led_toggle(LED_BLUE);
-    }
-    led_off(LED_BLUE);
-#endif
     led_on(LED_GREEN);
     /* Prepare FMC interface. */
     fmc_init();
@@ -228,21 +248,18 @@ int main()
      */
     hal_core_iterate(NULL);
 
-    uart_mutex = osMutexCreate(osMutex(uart_mutex));
-    dispatch_mutex = osMutexCreate(osMutex(dispatch_mutex));
-    rpc_sem = osSemaphoreCreate(osSemaphore(rpc_sem), 0);
-
-#ifdef TARGET_CRYPTECH_ALPHA
-    /* Launch other threads:
-     * - admin thread on USART1
-     * - csprng warm-up thread?
-     */
+#if NUM_RPC_TASK > 1
+    if ((uart_mutex = osMutexCreate(osMutex(uart_mutex))) == NULL ||
+        (dispatch_mutex = osMutexCreate(osMutex(dispatch_mutex)) == NULL)
+	Error_Handler();
 #endif
+    if ((rpc_sem = osSemaphoreCreate(osSemaphore(rpc_sem), 0)) == NULL)
+	Error_Handler();
 
-    if (hal_rpc_server_init() != HAL_OK)
+    if (hal_rpc_server_init() != LIBHAL_OK)
 	Error_Handler();
 
-    /* Create the rpc dispatch threads */
+    /* Create the rpc dispatch worker threads. */
     for (int i = 0; i < NUM_RPC_TASK; ++i) {
         osThreadDef_t *ot = &thread_def[i];
         ot->pthread = dispatch_thread;
@@ -255,8 +272,9 @@ int main()
             Error_Handler();
     }
 
-    /* Start the non-blocking receive */
-    HAL_UART_Receive_IT(&huart_user, (uint8_t *)&uart_rx, 1);
+    /* Launch other threads (csprng warm-up thread?)
+     * Wait for FPGA_DONE interrupt.
+     */
 
     return cli_main();
 }
diff --git a/projects/hsm/mgmt-fpga.c b/projects/hsm/mgmt-fpga.c
index b74392e..45bd33c 100644
--- a/projects/hsm/mgmt-fpga.c
+++ b/projects/hsm/mgmt-fpga.c
@@ -133,10 +133,37 @@ static int cmd_fpga_reset_registers(struct cli_def *cli, const char *command, ch
     return CLI_OK;
 }
 
+static int cmd_fpga_show_status(struct cli_def *cli, const char *command, char *argv[], int argc)
+{
+    cli_print(cli, "FPGA has %sloaded a bitstream", fpgacfg_check_done() ? "":"NOT ");
+    return CLI_OK;
+}
+
+static int cmd_fpga_show_cores(struct cli_def *cli, const char *command, char *argv[], int argc)
+{
+    const hal_core_t *core;
+    const hal_core_info_t *info;
+
+    for (core = hal_core_iterate(NULL); core != NULL; core = hal_core_iterate(core)) {
+	info = hal_core_info(core);
+	cli_print(cli, "%04x: %8.8s %4.4s",
+                  (unsigned int)info->base, info->name, info->version);
+    }
+
+    return CLI_OK;
+}
+
 void configure_cli_fpga(struct cli_def *cli)
 {
     /* fpga */
     cli_command_root(fpga);
+
+    cli_command_branch(fpga, show);
+    /* show fpga status*/
+    cli_command_node(fpga_show, status, "Show status about the FPGA");
+    /* show fpga cores*/
+    cli_command_node(fpga_show, cores, "Show FPGA core names and versions");
+
     /* fpga reset */
     cli_command_node(fpga, reset, "Reset FPGA (config reset)");
     /* fpga reset registers */
diff --git a/projects/hsm/mgmt-misc.c b/projects/hsm/mgmt-misc.c
index 67bc875..15b2d13 100644
--- a/projects/hsm/mgmt-misc.c
+++ b/projects/hsm/mgmt-misc.c
@@ -44,13 +44,6 @@
 extern uint32_t update_crc(uint32_t crc, uint8_t *buf, int len);
 
 
-static volatile uint32_t demo_crc = 0;
-
-static int _count_bytes_callback(uint8_t *buf, size_t len) {
-    demo_crc = update_crc(demo_crc, buf, len);
-    return 1;
-}
-
 int cli_receive_data(struct cli_def *cli, uint8_t *buf, size_t len, cli_data_callback data_callback)
 {
     uint32_t filesize = 0, crc = 0, my_crc = 0, counter = 0;
@@ -109,16 +102,6 @@ int cli_receive_data(struct cli_def *cli, uint8_t *buf, size_t len, cli_data_cal
     return CLI_OK;
 }
 
-static int cmd_filetransfer(struct cli_def *cli, const char *command, char *argv[], int argc)
-{
-    uint8_t buf[FILETRANSFER_UPLOAD_CHUNK_SIZE];
-
-    demo_crc = 0;
-    cli_receive_data(cli, &buf[0], sizeof(buf), _count_bytes_callback);
-    cli_print(cli, "Demo CRC is: %li/0x%x", demo_crc, (unsigned int) demo_crc);
-    return CLI_OK;
-}
-
 static int cmd_reboot(struct cli_def *cli, const char *command, char *argv[], int argc)
 {
     cli_print(cli, "\n\n\nRebooting\n\n\n");
@@ -130,8 +113,6 @@ static int cmd_reboot(struct cli_def *cli, const char *command, char *argv[], in
 
 void configure_cli_misc(struct cli_def *cli)
 {
-    /* filetransfer */
-    cli_command_root_node(filetransfer, "Test file transfering");
     /* reboot */
     cli_command_root_node(reboot, "Reboot the STM32");
 }