repo init. partial port of existing code

5 files changed, 125 insertions, 0 deletions

diff --git a/deps/fff/examples/weak_linking/src/bus.c b/deps/fff/examples/weak_linking/src/bus.c
new file mode 100644
index 0000000..5706932
--- /dev/null
+++ b/deps/fff/examples/weak_linking/src/bus.c
@@ -0,0 +1,30 @@
+#pragma once
+
+uint16_t* BUS_REGISTER_BASE = (uint16_t*)0xDEADBEEF;
+
+typedef struct
+{
+    uint16_t action;
+    uint16_t reg;
+    uint8_t  input;
+    uint8_t  output
+} BusDevice;
+
+BusDevice* BUS = (BusDevice*)BUS_REGISTER_BASE;
+
+bool bus_read_write( uint8_t dev, uint8_t registry, uint8_t* buffer, int len, bool assume_echo )
+{
+    // Something that we dont want to run, since the emulation would be hard.
+    BUS->action = 0x01;
+    BUS->reg = registry;
+    for ( int loop =0 ; loop < len; loop ++ )
+    {
+        char output = buffer[loop];
+        BUS->output  = output;
+        buffer[loop] = BUS->input;
+
+        if ( ( assume_echo ) && ( buffer[loop] != output ) )
+            return false;
+    }
+    return true;
+}
diff --git a/deps/fff/examples/weak_linking/src/display.c b/deps/fff/examples/weak_linking/src/display.c
new file mode 100644
index 0000000..1b9a7d6
--- /dev/null
+++ b/deps/fff/examples/weak_linking/src/display.c
@@ -0,0 +1,29 @@
+#include <string.h>
+
+#include "display.h"
+#include "bus.h"
+
+#define DISPLAY_ADDRESS     0xAF
+#define DISPLAY_REG_INIT    0x10
+#define DISPLAY_REG_UPDATE  0x20
+
+bool display_init()
+{
+    char init_config[] = { 0xDE, 0xFE, 0x00 };
+    bus_read_write( DISPLAY_ADDRESS, DISPLAY_REG_INIT, (uint8_t*)init_config, 3, false );
+
+    if (init_config[2] != 0x10)
+        return false;
+
+    return true;
+}
+
+void display_update( const char* info )
+{
+    int len = strlen( info );
+
+    if ( bus_write( DISPLAY_ADDRESS, DISPLAY_REG_UPDATE, (const uint8_t*)info, len, true ) != true )
+    {
+        runtime_error("display update failed!");
+    }
+}
diff --git a/deps/fff/examples/weak_linking/src/error.c b/deps/fff/examples/weak_linking/src/error.c
new file mode 100644
index 0000000..5e7db63
--- /dev/null
+++ b/deps/fff/examples/weak_linking/src/error.c
@@ -0,0 +1,10 @@
+#include <assert.h>
+#include "error.h"
+
+char* runtime_error_nice_print( const char* msg )
+{
+    char* buffer = malloc(512);
+    snprintf(buffer, 512, "Got error: %s", msg );
+    buffer[511] = 0;
+    return buffer;
+}
diff --git a/deps/fff/examples/weak_linking/src/main.c b/deps/fff/examples/weak_linking/src/main.c
new file mode 100644
index 0000000..88be84c
--- /dev/null
+++ b/deps/fff/examples/weak_linking/src/main.c
@@ -0,0 +1,27 @@
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "display.h"
+#include "sensor.h"
+
+void give_error( const char* msg )
+{
+    char* buffer = runtime_error_nice_print( msg );
+    runtime_error( buffer );
+    free(buffer);
+}
+
+int update_main( void )
+{
+    if ( !sensor_init() )
+        runtime_error("sensor init failed");
+
+    if ( !display_init() )
+        runtime_error("display init failed");
+
+    char buffer[32];
+    float reading = sensor_read();
+    snprintf( buffer, 32, "Sensor: %0.1f", reading );
+    display_update( buffer );
+    return 0;
+}
diff --git a/deps/fff/examples/weak_linking/src/sensor.c b/deps/fff/examples/weak_linking/src/sensor.c
new file mode 100644
index 0000000..bff6642
--- /dev/null
+++ b/deps/fff/examples/weak_linking/src/sensor.c
@@ -0,0 +1,29 @@
+#include <string.h>
+
+#include "sensor.h"
+#include "bus.h"
+
+#define SENSOR_ADDRESS 0xAA
+#define SENSOR_REG_READ 0xF0
+
+float LOCAL_buffer[4];
+
+bool sensor_init()
+{
+    memset( LOCAL_buffer, 0x00, sizeof(LOCAL_buffer));
+    return true;
+}
+
+float sensor_read()
+{
+    char data[4] = { 0xFF, 0xFF, 0x00, 0x00 };
+    bus_read_write( SENSOR_ADDRESS, SENSOR_REG_READ, (uint8_t*)&data, 4, false );
+
+    if (data[0] != 0x10)
+    {
+        runtime_error("sensor read failed");
+    }
+
+    float ret_value = data[1] + data[2] / 256.0;
+    return ret_value;
+}