Kernel: Implement TerminalDriver for Framebuffer device

Use this new FramebufferTerminalDriver for terminal instead of the
old VesaTerminalDriver. Only drawback with this is that framebuffer
device can only be intialized after DevFS is initialized.

kernel/kernel/FS/DevFS/FileSystem.cpp

@@ -23,10 +23,6 @@ namespace Kernel
 		MUST(s_instance->TmpFileSystem::initialize(0755, 0, 0));
 		s_instance->add_device(MUST(NullDevice::create(0666, 0, 0)));
 		s_instance->add_device(MUST(ZeroDevice::create(0666, 0, 0)));
-
-		auto fbdev_or_error = FramebufferDevice::create_from_boot_framebuffer();
-		if (!fbdev_or_error.is_error())
-			s_instance->add_device(fbdev_or_error.release_value());
 	}
 
 	DevFileSystem& DevFileSystem::get()

kernel/kernel/Terminal/FramebufferTerminal.cpp

@@ -0,0 +1,58 @@
+#include <kernel/Terminal/FramebufferTerminal.h>
+
+namespace Kernel
+{
+
+	FramebufferTerminalDriver* FramebufferTerminalDriver::create(BAN::RefPtr<FramebufferDevice> framebuffer_device)
+	{
+		auto* driver = new FramebufferTerminalDriver(framebuffer_device);
+		if (driver == nullptr)
+			return nullptr;
+		driver->set_cursor_position(0, 0);
+		driver->clear(TerminalColor::BLACK);
+		return driver;
+	}
+
+	void FramebufferTerminalDriver::putchar_at(uint16_t ch, uint32_t x, uint32_t y, Color fg, Color bg)
+	{
+		const uint8_t* glyph = font().has_glyph(ch) ? font().glyph(ch) : font().glyph('?');
+
+		x *= font().width();
+		y *= font().height();
+
+		for (uint32_t dy = 0; dy < font().height() && y + dy < m_framebuffer_device->height(); dy++)
+		{
+			for (uint32_t dx = 0; dx < font().width() && x + dx < m_framebuffer_device->width(); dx++)
+			{
+				const uint8_t bitmask = 1 << (font().width() - dx - 1);
+				const auto color = glyph[dy * font().pitch()] & bitmask ? fg : bg;
+				m_framebuffer_device->set_pixel(x + dx, y + dy, color.rgb);
+			}
+		}
+
+		m_framebuffer_device->sync_pixels_rectangle(x, y, font().width(), font().height());
+	}
+
+	void FramebufferTerminalDriver::clear(Color color)
+	{
+		for (uint32_t y = 0; y < m_framebuffer_device->height(); y++)
+			for (uint32_t x = 0; x < m_framebuffer_device->width(); x++)
+				m_framebuffer_device->set_pixel(x, y, color.rgb);
+		m_framebuffer_device->sync_pixels_full();
+	}
+
+	void FramebufferTerminalDriver::set_cursor_position(uint32_t x, uint32_t y)
+	{
+		const uint32_t cursor_h = font().height() / 8;
+		const uint32_t cursor_top = font().height() * 13 / 16;
+
+		x *= font().width();
+		y *= font().height();
+
+		for (uint32_t dy = 0; dy < cursor_h; dy++)
+			for (uint32_t dx = 0; dx < font().width(); dx++)
+				m_framebuffer_device->set_pixel(x + dx, y + cursor_top + dy, s_cursor_color.rgb);
+		m_framebuffer_device->sync_pixels_rectangle(x, y + cursor_top, font().width(), cursor_h);
+	}
+
+}

kernel/kernel/kernel.cpp

@@ -2,6 +2,7 @@
 #include <kernel/Arch.h>
 #include <kernel/BootInfo.h>
 #include <kernel/Debug.h>
+#include <kernel/Device/FramebufferDevice.h>
 #include <kernel/FS/DevFS/FileSystem.h>
 #include <kernel/FS/ProcFS/FileSystem.h>
 #include <kernel/FS/VirtualFileSystem.h>
@@ -20,7 +21,7 @@
 #include <kernel/Syscall.h>
 #include <kernel/Terminal/Serial.h>
 #include <kernel/Terminal/VirtualTTY.h>
-#include <kernel/Terminal/VesaTerminalDriver.h>
+#include <kernel/Terminal/FramebufferTerminal.h>
 #include <kernel/Timer/Timer.h>
 
 struct ParsedCommandLine
@@ -108,10 +109,6 @@ extern "C" void kernel_main(uint32_t boot_magic, uint32_t boot_info)
 	PageTable::initialize();
 	dprintln("PageTable initialized");
 
-	g_terminal_driver = VesaTerminalDriver::create();
-	if (g_terminal_driver)
-		dprintln("VESA initialized");
-
 	Heap::initialize();
 	dprintln("Heap initialzed");
 
@@ -130,6 +127,12 @@ extern "C" void kernel_main(uint32_t boot_magic, uint32_t boot_info)
 	DevFileSystem::initialize();
 	dprintln("devfs initialized");
 
+	auto framebuffer_device = FramebufferDevice::create_from_boot_framebuffer();
+	if (!framebuffer_device.is_error())
+		g_terminal_driver = FramebufferTerminalDriver::create(framebuffer_device.value());
+	if (g_terminal_driver)
+		dprintln("Framebuffer terminal initialized");
+
 	ProcFileSystem::initialize();
 	dprintln("procfs initialized");