m-labs · Dec 26, 2015 · Dec 26, 2015 · Dec 26, 2015
diff --git a/artiq/gateware/rtio/__init__.py b/artiq/gateware/rtio/__init__.py
@@ -1,3 +1,3 @@
-from artiq.gateware.rtio.core import Channel, RTIO
+from artiq.gateware.rtio.core import Channel, LogChannel, RTIO
 from artiq.gateware.rtio.analyzer import Analyzer
 from artiq.gateware.rtio.moninj import MonInj
diff --git a/artiq/gateware/rtio/core.py b/artiq/gateware/rtio/core.py
@@ -310,6 +310,15 @@ def from_phy(cls, phy, **kwargs):
         return cls(phy.rtlink, probes, overrides, **kwargs)
 
 
+class LogChannel:
+    """A degenerate channel used to log messages into the analyzer."""
+    def __init__(self):
+        self.interface = rtlink.Interface(
+            rtlink.OInterface(32, suppress_nop=False))
+        self.probes = []
+        self.overrides = []
+
+
 class _KernelCSRs(AutoCSR):
     def __init__(self, chan_sel_width,
                  data_width, address_width, full_ts_width):
@@ -385,6 +394,12 @@ def __init__(self, channels, full_ts_width=63, guard_io_cycles=20):
         o_statuses, i_statuses = [], []
         sel = self.kcsrs.chan_sel.storage
         for n, channel in enumerate(channels):
+            if isinstance(channel, LogChannel):
+                i_datas.append(0)
+                i_timestamps.append(0)
+                i_statuses.append(0)
+                continue
+
             selected = Signal()
             self.comb += selected.eq(sel == n)
 

diff --git a/artiq/gateware/targets/kc705.py b/artiq/gateware/targets/kc705.py
@@ -185,6 +185,10 @@ def __init__(self, cpu_type="or1k", **kwargs):
         rtio_channels.append(rtio.Channel.from_phy(phy,
                                                    ofifo_depth=512,
                                                    ififo_depth=4))
+
+        self.config["RTIO_LOG_CHANNEL"] = len(rtio_channels)
+        rtio_channels.append(rtio.LogChannel())
+
         self.add_rtio(rtio_channels)
 
 
@@ -230,6 +234,10 @@ def __init__(self, cpu_type="or1k", **kwargs):
         rtio_channels.append(rtio.Channel.from_phy(phy,
                                                    ofifo_depth=512,
                                                    ififo_depth=4))
+
+        self.config["RTIO_LOG_CHANNEL"] = len(rtio_channels)
+        rtio_channels.append(rtio.LogChannel())
+
         self.add_rtio(rtio_channels)
 
 

diff --git a/artiq/gateware/targets/pipistrello.py b/artiq/gateware/targets/pipistrello.py
@@ -190,6 +190,9 @@ def __init__(self, cpu_type="or1k", **kwargs):
                                                    ofifo_depth=512,
                                                    ififo_depth=4))
 
+        self.config["RTIO_LOG_CHANNEL"] = len(rtio_channels)
+        rtio_channels.append(rtio.LogChannel())
+
         # RTIO core
         self.submodules.rtio = rtio.RTIO(rtio_channels)
         self.config["RTIO_FINE_TS_WIDTH"] = self.rtio.fine_ts_width

diff --git a/artiq/runtime/analyzer.c b/artiq/runtime/analyzer.c
@@ -71,7 +71,7 @@ void analyzer_start(void)
         analyzer_header.sent_bytes = analyzer_header.total_byte_count;
 
     analyzer_header.overflow_occured = rtio_analyzer_message_encoder_overflow_read();
-    analyzer_header.log_channel = 0;
+    analyzer_header.log_channel = CONFIG_RTIO_LOG_CHANNEL;
     analyzer_header.dds_channel = CONFIG_RTIO_DDS_CHANNEL;
 #ifdef DDS_ONEHOT_SEL
     analyzer_header.dds_onehot_sel = 1;

diff --git a/artiq/runtime/ksupport.c b/artiq/runtime/ksupport.c
@@ -107,6 +107,7 @@ static const struct symbol runtime_exports[] = {
 
     /* direct syscalls */
     {"rtio_get_counter", &rtio_get_counter},
+    {"rtio_log", &rtio_log},
 
     {"ttl_set_o", &ttl_set_o},
     {"ttl_set_oe", &ttl_set_oe},
@@ -167,13 +168,15 @@ int fprintf(FILE *stream, const char *fmt, ...)
 }
 
 /* called by libunwind */
-int dladdr (const void *address, Dl_info *info) {
+int dladdr (const void *address, Dl_info *info)
+{
     /* we don't try to resolve names */
     return 0;
 }
 
 /* called by libunwind */
-int dl_iterate_phdr (int (*callback) (struct dl_phdr_info *, size_t, void *), void *data) {
+int dl_iterate_phdr (int (*callback)(struct dl_phdr_info *, size_t, void *), void *data)
+{
     Elf32_Ehdr *ehdr;
     struct dl_phdr_info phdr_info;
     int retval;
@@ -200,7 +203,8 @@ int dl_iterate_phdr (int (*callback) (struct dl_phdr_info *, size_t, void *), vo
     return retval;
 }
 
-static Elf32_Addr resolve_runtime_export(const char *name) {
+static Elf32_Addr resolve_runtime_export(const char *name)
+{
     const struct symbol *sym = runtime_exports;
     while(sym->name) {
         if(!strcmp(sym->name, name))

diff --git a/artiq/runtime/rtio.c b/artiq/runtime/rtio.c
@@ -38,3 +38,32 @@ void rtio_process_exceptional_status(int status, long long int timestamp, int ch
             timestamp, channel, 0);
     }
 }
+
+void rtio_log(long long int timestamp, char *message)
+{
+    unsigned int word;
+    int i;
+
+    rtio_chan_sel_write(CONFIG_RTIO_LOG_CHANNEL);
+    rtio_o_timestamp_write(timestamp);
+
+    i = 0;
+    word = 0;
+    while(1) {
+        word >>= 8;
+        word |= *message << 24;
+        if(*message == 0) {
+            rtio_o_data_write(word);
+            rtio_o_we_write(1);
+            break;
+        }
+        message++;
+        i++;
+        if(i == 4) {
+            rtio_o_data_write(word);
+            rtio_o_we_write(1);
+            word = 0;
+            i = 0;
+        }
+    }
+}
diff --git a/artiq/runtime/rtio.h b/artiq/runtime/rtio.h
@@ -14,6 +14,7 @@
 void rtio_init(void);
 long long int rtio_get_counter(void);
 void rtio_process_exceptional_status(int status, long long int timestamp, int channel);
+void rtio_log(long long int timestamp, char *message);
 
 static inline void rtio_write_and_process_status(long long int timestamp, int channel)
 {