5650 - support a second OS: soso

https://github.com/ozkl/soso

+ Much smaller than Linux; builds instantly
+ Supports graphics
- No network support
- Doesn't work on a cloud server (yet?)

1 files changed, 102 insertions, 0 deletions

diff --git a/kernel.soso/fifobuffer.c b/kernel.soso/fifobuffer.c
new file mode 100644
index 00000000..53fd6f38
--- /dev/null
+++ b/kernel.soso/fifobuffer.c
@@ -0,0 +1,102 @@
+#include "fifobuffer.h"
+#include "alloc.h"
+
+FifoBuffer* FifoBuffer_create(uint32 capacity)
+{
+    FifoBuffer* fifo = (FifoBuffer*)kmalloc(sizeof(FifoBuffer));
+    memset((uint8*)fifo, 0, sizeof(FifoBuffer));
+    fifo->data = (uint8*)kmalloc(capacity);
+    memset((uint8*)fifo->data, 0, capacity);
+    fifo->capacity= capacity;
+
+    return fifo;
+}
+
+void FifoBuffer_destroy(FifoBuffer* fifoBuffer)
+{
+    kfree(fifoBuffer->data);
+    kfree(fifoBuffer);
+}
+
+void FifoBuffer_clear(FifoBuffer* fifoBuffer)
+{
+    fifoBuffer->usedBytes = 0;
+    fifoBuffer->readIndex = 0;
+    fifoBuffer->writeIndex = 0;
+}
+
+BOOL FifoBuffer_isEmpty(FifoBuffer* fifoBuffer)
+{
+    if (0 == fifoBuffer->usedBytes)
+    {
+        return TRUE;
+    }
+
+    return FALSE;
+}
+
+uint32 FifoBuffer_getSize(FifoBuffer* fifoBuffer)
+{
+    return fifoBuffer->usedBytes;
+}
+
+uint32 FifoBuffer_getCapacity(FifoBuffer* fifoBuffer)
+{
+    return fifoBuffer->capacity;
+}
+
+uint32 FifoBuffer_getFree(FifoBuffer* fifoBuffer)
+{
+    return fifoBuffer->capacity - fifoBuffer->usedBytes;
+}
+
+int32 FifoBuffer_enqueue(FifoBuffer* fifoBuffer, uint8* data, uint32 size)
+{
+    if (size == 0)
+    {
+        return -1;
+    }
+
+    uint32 bytesAvailable = fifoBuffer->capacity - fifoBuffer->usedBytes;
+
+    if (size > bytesAvailable)
+    {
+        return -1;
+    }
+
+    uint32 i = 0;
+    while (fifoBuffer->usedBytes < fifoBuffer->capacity && i < size)
+    {
+        fifoBuffer->data[fifoBuffer->writeIndex] = data[i++];
+        fifoBuffer->usedBytes++;
+        fifoBuffer->writeIndex++;
+        fifoBuffer->writeIndex %= fifoBuffer->capacity;
+    }
+
+    return size;
+}
+
+int32 FifoBuffer_dequeue(FifoBuffer* fifoBuffer, uint8* data, uint32 size)
+{
+    if (size == 0)
+    {
+        return -1;
+    }
+
+    if (0 == fifoBuffer->usedBytes)
+    {
+        //Buffer is empty
+        return 0;
+    }
+
+    uint32 i = 0;
+    while (fifoBuffer->usedBytes > 0 && i < size)
+    {
+        data[i++] = fifoBuffer->data[fifoBuffer->readIndex];
+        fifoBuffer->usedBytes--;
+        fifoBuffer->readIndex++;
+        fifoBuffer->readIndex %= fifoBuffer->capacity;
+    }
+
+    return i;
+}