[Qemu-devel] [PATCH 6/7] scenario engine: provide a scenario file template

[Victor CLEMENT]

This template implements the mandatory functions of the main scenario
source file and provides an example use case.

Signed-off-by: Victor CLEMENT <address@hidden>
---
 Makefile.objs               |   1 +
 include/scenario/scenario.h |   5 ++
 scenario/scenario.c         | 168 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 174 insertions(+)
 create mode 100644 include/scenario/scenario.h
 create mode 100644 scenario/scenario.c

diff --git a/Makefile.objs b/Makefile.objs
index 112794d..aa38f42 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -108,6 +108,7 @@ target-obj-y += trace/
 
 ######################################################################
 # scenario
+util-obj-$(CONFIG_SCENARIO) +=  scenario/scenario.o
 util-obj-$(CONFIG_SCENARIO) +=  scenario/scheduler.o
 util-obj-$(CONFIG_SCENARIO) +=  scenario/utils.o
 
diff --git a/include/scenario/scenario.h b/include/scenario/scenario.h
new file mode 100644
index 0000000..50ffc6d
--- /dev/null
+++ b/include/scenario/scenario.h
@@ -0,0 +1,5 @@
+#include "scenario/scheduler.h"
+#include "hw/gpio/pl061_simu.h"
+
+void init_scenario_engine(const char *filename);
+
diff --git a/scenario/scenario.c b/scenario/scenario.c
new file mode 100644
index 0000000..a237ecb
--- /dev/null
+++ b/scenario/scenario.c
@@ -0,0 +1,168 @@
+/*
+ * This is the scenario example file
+ *
+ * This example writes on a gpio pin for each event in the simulation file
+ *
+ * The simulation file should contain timestamps and a (unique) optional
+ * parameter for each timestamp.
+ * A timestamp line begins with '#' and a parameter line begins with '%', the
+ * whole line after '%' will be passed to the callback.
+ * Timestamps unit is nanosecond after sched_start
+ *
+ * ex.:
+ * #10000
+ * %parameter for timestamp 10000
+ * %this parameter line will be ignored
+ * #20000
+ * #30000
+ * ...
+ */
+
+#include "scenario/scenario.h"
+#include "scenario/utils.h"
+#include "sysemu/char.h"
+#include "trace.h"
+
+// #define DEBUG_SCENARIO
+
+#ifdef DEBUG_SCENARIO
+#define DPRINTF(fmt, ...) \
+    do { printf("scenario: " fmt, ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) do {} while (0)
+#endif
+
+static const char *simu_file;
+
+/*
+ * This callback will be called for each event in the simulation file if the
+ * the scheduler is used
+ *
+ * opaque: the opaque pointer passed to sched_start
+ * ts: the value of the timestamp which triggered this callback
+ * param: the parameter associated whith this timestamp
+ */
+static void scenario_scheduler_cb(void *opaque, uint64_t ts, char *param)
+{
+    static uint8_t old_value = 0xFF;
+    uint8_t value;
+
+    DPRINTF("Scheduler callback\n");
+    /*
+     * Checking the parameter
+     * "" -> send a signal on the GPIO2 pin
+     * "check" -> check the value of the GPIO1 pin
+     */
+    if (!strcmp(param, "check")) {
+        value = pl061_simu_read(opaque, 01);
+        if (old_value == 0xFF) {
+            old_value = value;
+        } else {
+            if (((old_value^value) & 01) == 01) {
+                printf("Toogle okay @%lu\n", ts);
+            } else {
+                printf("Toogle error @%lu\n", ts);
+            }
+            old_value = old_value^01;
+        }
+    } else {
+        /*
+         * Send a signal to the GPIO2 pin
+         */
+        pl061_simu_write(opaque, 02, 02);
+        pl061_simu_write(opaque, 02, 00);
+    }
+
+    return;
+}
+
+/*
+ * The virtual device callback
+ * This function will be called on each event in the tested device emulator
+ *
+ * Its prototype have to be the same as the one defined in the scenario header
+ * of your emulator
+ * e.x: for the pl061, the header is located in include/hw/gpio/pl061_simu.h
+ *      Here, there is a typedef which defines the callback prototype you would
+ *      have to follow
+ *
+ * See scenario_register_emulator_cb documentation for more details
+ */
+static void scenario_device_cb(void *opaque,
+        const char *type,
+        unsigned int simu_id)
+{
+    DPRINTF("Device event callabck: (%s #%d)\n", type, simu_id);
+    /*
+     * Tracing events from here
+     */
+    trace_gpio_write(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
+            0, pl061_simu_read(opaque, 0xFF));
+    /*
+     * Then try to start the scheduler at the first emulator event
+     *
+     * This call has no effect if the scheduler is already started (returns 2)
+     */
+    if (scenario_scheduler_start(scenario_scheduler_cb, opaque, simu_file) < 1)
+    {
+        printf("Warning: scenario scheduler did not start\n");
+    }
+}
+
+/*
+ * Function to send characters one by one to a character device
+ */
+static int send_chars(struct CharDriverState *chr, const char* buffer, int len)
+{
+    int i;
+    for (i = 0 ; i < len ; i++) {
+        qemu_chr_be_write(chr, (uint8_t *)(buffer+i), 1);
+    }
+    return len;
+}
+
+/*
+ * The character device emulator callback.
+ * It is called everytime data is written in the associated chardev frontend
+ * (ex. serial port)
+ *
+ * Its prototype is defined in include/sysemu/char.h (at the end)
+ *
+ * This callback have to be registered with the scenario_register_chardev_cb
+ * function
+ */
+static int char_simu_handler(struct CharDriverState *chr,
+        const uint8_t *buf,
+        int len)
+{
+    DPRINTF("Char custom handler called\n");
+    send_chars(chr, "Hi!\r\n", 5);
+    return len;
+}
+
+/*
+ * This is the entry point.
+ * This initialisation function is called when qemu starts, after devices init
+ *
+ * filename: the file name of the simulation file given in qemu invocation
+ */
+void init_scenario_engine(const char *filename)
+{
+    printf("Init simulation\n");
+    simu_file = filename;
+    /*
+     * Register device event callback
+     *
+     * e.x. pl061 event callback is registered to the function
+     * scenario_device_cb here
+     */
+    scenario_register_emulator_cb("pl061", pl061_simu_register_cb,
+            scenario_device_cb);
+    /*
+     * Register chardev event callback
+     *
+     * Here the event callback of the chardev identified by "scen0"
+     * is registered to char_simu_handler function
+     */
+    scenario_register_chardev_cb("scen0", char_simu_handler, true);
+}
-- 
2.5.1