From 46bb1d3157f9ad575c83a4bfa1e32b0d21bc8546 Mon Sep 17 00:00:00 2001
From: Kartik Agaram <vc@akkartik.com>
Date: Sat, 14 Sep 2019 01:42:29 -0700
Subject: 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?)
---
 kernel.soso/ramdisk.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 120 insertions(+)
 create mode 100644 kernel.soso/ramdisk.c

(limited to 'kernel.soso/ramdisk.c')

diff --git a/kernel.soso/ramdisk.c b/kernel.soso/ramdisk.c
new file mode 100644
index 00000000..d48e20ff
--- /dev/null
+++ b/kernel.soso/ramdisk.c
@@ -0,0 +1,120 @@
+#include "ramdisk.h"
+#include "alloc.h"
+#include "fs.h"
+#include "devfs.h"
+
+typedef struct Ramdisk
+{
+    uint8* buffer;
+    uint32 size;
+} Ramdisk;
+
+#define RAMDISK_BLOCKSIZE 512
+
+static BOOL open(File *file, uint32 flags);
+static void close(File *file);
+static int32 readBlock(FileSystemNode* node, uint32 blockNumber, uint32 count, uint8* buffer);
+static int32 writeBlock(FileSystemNode* node, uint32 blockNumber, uint32 count, uint8* buffer);
+static int32 ioctl(File *node, int32 request, void * argp);
+
+BOOL createRamdisk(const char* devName, uint32 size)
+{
+    Ramdisk* ramdisk = kmalloc(sizeof(Ramdisk));
+    ramdisk->size = size;
+    ramdisk->buffer = kmalloc(size);
+
+    Device device;
+    memset((uint8*)&device, 0, sizeof(device));
+    strcpy(device.name, devName);
+    device.deviceType = FT_BlockDevice;
+    device.open = open;
+    device.close = close;
+    device.readBlock = readBlock;
+    device.writeBlock = writeBlock;
+    device.ioctl = ioctl;
+    device.privateData = ramdisk;
+
+    if (registerDevice(&device))
+    {
+        return TRUE;
+    }
+
+    kfree(ramdisk->buffer);
+    kfree(ramdisk);
+
+    return FALSE;
+}
+
+static BOOL open(File *file, uint32 flags)
+{
+    return TRUE;
+}
+
+static void close(File *file)
+{
+}
+
+static int32 readBlock(FileSystemNode* node, uint32 blockNumber, uint32 count, uint8* buffer)
+{
+    Ramdisk* ramdisk = (Ramdisk*)node->privateNodeData;
+
+    uint32 location = blockNumber * RAMDISK_BLOCKSIZE;
+    uint32 size = count * RAMDISK_BLOCKSIZE;
+
+    if (location + size > ramdisk->size)
+    {
+        return -1;
+    }
+
+    beginCriticalSection();
+
+    memcpy(buffer, ramdisk->buffer + location, size);
+
+    endCriticalSection();
+
+    return 0;
+}
+
+static int32 writeBlock(FileSystemNode* node, uint32 blockNumber, uint32 count, uint8* buffer)
+{
+    Ramdisk* ramdisk = (Ramdisk*)node->privateNodeData;
+
+    uint32 location = blockNumber * RAMDISK_BLOCKSIZE;
+    uint32 size = count * RAMDISK_BLOCKSIZE;
+
+    if (location + size > ramdisk->size)
+    {
+        return -1;
+    }
+
+    beginCriticalSection();
+
+    memcpy(ramdisk->buffer + location, buffer, size);
+
+    endCriticalSection();
+
+    return 0;
+}
+
+static int32 ioctl(File *node, int32 request, void * argp)
+{
+    Ramdisk* ramdisk = (Ramdisk*)node->node->privateNodeData;
+
+    uint32* result = (uint32*)argp;
+
+    switch (request)
+    {
+    case IC_GetSectorCount:
+        *result = ramdisk->size / RAMDISK_BLOCKSIZE;
+        return 0;
+        break;
+    case IC_GetSectorSizeInBytes:
+        *result = RAMDISK_BLOCKSIZE;
+        return 0;
+        break;
+    default:
+        break;
+    }
+
+    return -1;
+}
-- 
cgit 1.4.1-2-gfad0