Added memory management using paging

This was quite a roller-coaster and most things are slower now, but it works and is way more secure. I still need to implement things like shared memory for the WM/GUI system but other than that everything is supported.

1 files changed, 64 insertions, 0 deletions

diff --git a/kernel/drivers/fb.c b/kernel/drivers/fb.c
new file mode 100644
index 0000000..8e73f5b
--- /dev/null
+++ b/kernel/drivers/fb.c
@@ -0,0 +1,64 @@
+// MIT License, Copyright (c) 2021 Marvin Borner
+
+#include <assert.h>
+#include <def.h>
+#include <fb.h>
+#include <fs.h>
+#include <ioctl.h>
+#include <mem.h>
+#include <mm.h>
+#include <str.h>
+#include <sys.h>
+
+struct vbe_basic {
+	u8 stuff1[16];
+	u16 pitch;
+	u16 width;
+	u16 height;
+	u8 stuff2[18];
+	u8 *fb;
+	u8 stuff3[212];
+};
+
+static u32 dev_id = 0;
+static struct vid_info *info = NULL;
+
+static s32 fb_ioctl(u32 request, void *arg1, void *arg2, void *arg3, struct device *dev)
+{
+	UNUSED(arg2);
+	UNUSED(arg3);
+	UNUSED(dev);
+
+	switch (request) {
+	case IO_FB_GET: {
+		if (!info)
+			return -1;
+		struct vbe_basic *vbe = (struct vbe_basic *)info->vbe;
+		memcpy(arg1, info->vbe, sizeof(struct vbe_basic));
+		u32 size = vbe->height * vbe->pitch;
+		memory_map_identity(proc_current()->page_dir,
+				    memory_range_around((u32)vbe->fb, size), MEMORY_USER);
+		return 0;
+	}
+	default:
+		return -1;
+	}
+}
+
+static u8 fb_ready(void)
+{
+	return 1;
+}
+
+void fb_install(struct vid_info *boot)
+{
+	info = boot;
+
+	struct device *dev = zalloc(sizeof(*dev));
+	dev->name = strdup("fb");
+	dev->type = DEV_CHAR;
+	dev->ioctl = fb_ioctl;
+	dev->ready = fb_ready;
+	device_add(dev);
+	dev_id = dev->id;
+}