Added VGA API allowing userspace to easily access 0xB8000.

libmaxsi/Makefile

@@ -44,8 +44,8 @@ c/h/stdio.h
 
 COMMONOBJS=c++.o thread.o io.o memory.o string.o error.o format.o
 SORTIXOBJS:=$(addprefix sortix/,$(COMMONOBJS))
-LIBMAXSIOBJS:=$(COMMONOBJS)
-HEADERS=error.h io.h memory.h platform.h string.h syscall.h thread.h types.h format.h
+LIBMAXSIOBJS:=$(COMMONOBJS) sortix-vga.o
+HEADERS=error.h io.h memory.h platform.h string.h syscall.h thread.h types.h format.h sortix-vga.h
 
 OBJS:=$(LIBMAXSIOBJS)
 BINS:=libmaxsi.so

libmaxsi/hsrc/sortix-vga.h

@@ -0,0 +1,76 @@
+/******************************************************************************
+
+	COPYRIGHT(C) JONAS 'SORTIE' TERMANSEN 2011.
+
+	This file is part of LibMaxsi.
+
+	LibMaxsi is free software: you can redistribute it and/or modify it under
+	the terms of the GNU Lesser General Public License as published by the Free
+	Software Foundation, either version 3 of the License, or (at your option)
+	any later version.
+
+	LibMaxsi is distributed in the hope that it will be useful, but WITHOUT ANY
+	WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+	FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
+	more details.
+
+	You should have received a copy of the GNU Lesser General Public License
+	along with LibMaxsi. If not, see <http://www.gnu.org/licenses/>.
+
+	sortix-vga.h
+	Provides access to the VGA framebuffer under Sortix. This is highly
+	unportable and is very likely to be removed or changed radically.
+
+******************************************************************************/
+
+#ifndef LIBMAXSI_SORTIX_VGA_H
+#define LIBMAXSI_SORTIX_VGA_H
+
+namespace System
+{
+	namespace VGA
+	{
+		// This is the contents of a VGA framebuffer used in text mode. The
+		// lower 8 lower bits correspond to an ASCII character, the next 4 bits
+		// is the text color, and the upper 4 bits are the background color.
+		struct Frame
+		{
+		public:
+			// The width of each line in characters.
+			const static size_t width = 80;
+
+			// The number of lines.
+			const static size_t height = 25;
+
+			// The data containing the frame.
+			uint16_t text[width * height];
+
+			// An opaque file descriptor that defines this frame. Used to change
+			// the current frame or deleting frames.
+			int fd;
+
+			// Beware: The kernel may or may keep more hidden data here. You may
+			// not depend on the usage of this area.
+
+		private:
+			// Only the kernel may create an instance of this structure.
+			Frame() { }
+
+		};
+
+		// Allocates a framebuffer able to store VGA data. This buffer is not
+		// relocatable and must remain at this position.
+		Frame* CreateFrame();
+
+		// Sets the process' current VGA frame. If the process currently have
+		// focus, then this is the frame shown on the screen. Any edits done
+		// on this frame while it is active will be shown instantly on the
+		// screen if the process have focus.
+		int ChangeFrame(int fd);
+
+		// Deletes a frame. This is equivalent to IO::Close(fd).
+		int DeleteFrame(int fd);
+	}
+}
+
+#endif

libmaxsi/sortix-vga.cpp

@@ -0,0 +1,54 @@
+/******************************************************************************
+
+	COPYRIGHT(C) JONAS 'SORTIE' TERMANSEN 2011.
+
+	This file is part of LibMaxsi.
+
+	LibMaxsi is free software: you can redistribute it and/or modify it under
+	the terms of the GNU Lesser General Public License as published by the Free
+	Software Foundation, either version 3 of the License, or (at your option)
+	any later version.
+
+	LibMaxsi is distributed in the hope that it will be useful, but WITHOUT ANY
+	WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+	FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
+	more details.
+
+	You should have received a copy of the GNU Lesser General Public License
+	along with LibMaxsi. If not, see <http://www.gnu.org/licenses/>.
+
+	sortix-vga.cpp
+	Provides access to the VGA framebuffer under Sortix. This is highly
+	unportable and is very likely to be removed or changed radically.
+
+******************************************************************************/
+
+#include "platform.h"
+#include "syscall.h"
+#include "sortix-vga.h"
+
+namespace System
+{
+	namespace VGA
+	{
+		
+		DEFN_SYSCALL0(Frame*, SysCreateFrame, 5);
+		DEFN_SYSCALL1(int, SysChangeFrame, 6, int);
+		DEFN_SYSCALL1(int, SysDeleteFrame, 7, int);
+
+		Frame* CreateFrame()
+		{
+			return SysCreateFrame();
+		}
+
+		int ChangeFrame(int fd)
+		{
+			return SysChangeFrame(fd);
+		}
+
+		int DeleteFrame(int fd)
+		{
+			return SysDeleteFrame(fd);
+		}
+	}
+}

sortix/Makefile

@@ -43,7 +43,7 @@ DEFINES:=$(DEFINES) -DINITRD
 CPPFLAGSRELEASE=-s -O3
 CPPFLAGSDEBUG=
 CPPFLAGS=-I.. $(CPUDEFINES) $(CPUFLAGS) -std=gnu++0x -Wall -Wextra -nostdlib -fno-builtin -nostartfiles -nodefaultlibs -fno-exceptions -fno-rtti -fno-stack-protector $(DEFINES) $(CPPFLAGSRELEASE)
-OBJS=$(CPUOBJS) kernel.o descriptor_tables.o isr.o time.o log.o iprintable.o panic.o keyboard.o memorymanagement.o scheduler.o syscall.o application.o pong.o sound.o pci.o uart.o conway.o test.o http.o vgaterminal.o serialterminal.o descriptors.o device.o ../libmaxsi/libmaxsi-sortix.a
+OBJS=$(CPUOBJS) kernel.o descriptor_tables.o isr.o time.o log.o iprintable.o panic.o keyboard.o memorymanagement.o scheduler.o syscall.o application.o pong.o sound.o pci.o uart.o conway.o test.o http.o vgaterminal.o serialterminal.o descriptors.o device.o vga.o ../libmaxsi/libmaxsi-sortix.a
 JSOBJS:=$(subst .o,-js.o,$(OBJS))
 
 all: sortix.bin

sortix/syscall.cpp

@@ -31,6 +31,7 @@
 #include "iprintable.h"
 #include "log.h"
 #include "panic.h"
+#include "vga.h"
 
 namespace Sortix
 {
@@ -47,7 +48,7 @@ namespace Sortix
 #endif
 		}
 
-		const size_t NumSyscalls = 5;
+		const size_t NumSyscalls = 8;
 		const Syscall Syscalls[NumSyscalls] =
 		{
 			&Scheduler::SysCreateThread,
@@ -55,6 +56,9 @@ namespace Sortix
 			&Scheduler::SysSleep,
 			&Scheduler::SysUSleep,
 			&SysStdOutPrint,
+			&VGA::SysCreateFrame,
+			&VGA::SysChangeFrame,
+			&VGA::SysDeleteFrame,
 		};
 
 		void Init()

sortix/vga.cpp

@@ -0,0 +1,185 @@
+/******************************************************************************
+
+	COPYRIGHT(C) JONAS 'SORTIE' TERMANSEN 2011.
+
+	This file is part of Sortix.
+
+	Sortix is free software: you can redistribute it and/or modify it under the
+	terms of the GNU General Public License as published by the Free Software
+	Foundation, either version 3 of the License, or (at your option) any later
+	version.
+
+	Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
+	WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+	FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+	details.
+
+	You should have received a copy of the GNU General Public License along
+	with Sortix. If not, see <http://www.gnu.org/licenses/>.
+
+	vga.h
+	A Video Graphics Array driver.
+
+******************************************************************************/
+
+#include "platform.h"
+#include <libmaxsi/memory.h>
+#include "vga.h"
+#include "memorymanagement.h"
+#include "scheduler.h"
+
+using namespace Maxsi;
+
+namespace Sortix
+{
+	namespace VGA
+	{
+		uint16_t* const vga = (uint16_t* const) 0xB8000;
+
+		DevVGAFrame* currentframe;
+
+		void Init()
+		{
+			currentframe = NULL;
+		}
+
+		void SysCreateFrame(CPU::InterruptRegisters* R)
+		{
+			addr_t page = Page::Get();
+			if ( page == NULL ) { R->eax = 0; return; }
+
+			Process* process = CurrentProcess();
+			addr_t mapto = Page::AlignUp(process->_endcodesection);
+			UserFrame* userframe = (UserFrame*) mapto;
+
+			// TODO: Check if mapto collides with any other memory section!
+
+			if ( !VirtualMemory::MapUser(mapto, page) )
+			{
+				Page::Put(page); R->eax = 0; return;
+			}
+
+			Memory::Set(userframe, 0, sizeof(UserFrame));
+
+			DevVGAFrame* frame = new DevVGAFrame();
+			if ( frame == NULL )
+			{
+				VirtualMemory::UnmapUser(mapto);
+				Page::Put(page); R->eax = 0; return;
+			}
+
+			int fd = process->descriptors.Allocate(frame);
+			if ( fd < 0 )
+			{
+				delete frame;
+				VirtualMemory::UnmapUser(mapto);
+				Page::Put(page); R->eax = 0; return;
+			}
+
+			userframe->fd = fd;
+
+			frame->process = process;
+			frame->physical = page;
+			frame->userframe = userframe;
+
+			process->_endcodesection = mapto + 0x1000;
+
+			R->eax = mapto;
+		}
+
+		void SysChangeFrame(CPU::InterruptRegisters* R)
+		{
+			int fd = (int) R->ebx;
+
+			Process* process = CurrentProcess();
+			Device* device = process->descriptors.Get(fd);
+			if ( device == NULL ) { R->eax = -1; return; }
+
+			if ( !device->IsType(Device::VGABUFFER) ) { R->eax = -2; return; }
+
+			DevVGAFrame* frame = (DevVGAFrame*) device;
+
+			ASSERT(frame->process == process);
+			ASSERT(frame->physical != 0);
+			ASSERT(frame->userframe != NULL);
+			ASSERT(frame->onscreen == (frame == currentframe));
+
+			// TODO: Check if userframe is actually user-space writable!
+
+			//Log::PrintF("changeframe: fd = %u, frame = 0x%p, currentframe = 0x%p\n", fd, frame, currentframe);
+
+			// Check if we need to do anything.
+			if ( frame == currentframe ) { R->eax = 0; return; }
+
+			// If there is already a currently used frame? If so, swap it from
+			// the VGA memory and back to the RAM. This should be done
+			// transparently such that the program doesn't feel the difference. 
+			if ( currentframe != NULL )
+			{
+				ASSERT(currentframe->physical != frame->physical);
+				ASSERT(currentframe->userframe != frame->userframe);
+				ASSERT(currentframe->onscreen == true);
+
+				if ( currentframe->process != process )
+				{
+					VirtualMemory::SwitchAddressSpace(currentframe->process->GetAddressSpace());
+				}
+
+				// Remap the pages in the owning process.
+				// TODO: Check if userframe is actually user-space writable!
+				VirtualMemory::UnmapUser((addr_t) currentframe->userframe);
+				VirtualMemory::MapUser((addr_t) currentframe->userframe, currentframe->physical);
+
+				// Restore the contents of this frame to the VGA framebuffer.
+				Memory::Copy(currentframe->userframe, vga, sizeof(UserFrame));
+
+				if ( currentframe->process != process )
+				{
+					VirtualMemory::SwitchAddressSpace(process->GetAddressSpace());
+				}
+
+				currentframe->onscreen = false;
+			}
+
+			// Now move the contents of this frame to the VGA framebuffer.
+			Memory::Copy(vga, frame->userframe, sizeof(UserFrame));
+
+			// Remap the pages such that the current process now uses the vga.
+			VirtualMemory::UnmapUser((addr_t) frame->userframe);
+			VirtualMemory::MapUser((addr_t) frame->userframe, (addr_t) vga);
+
+			frame->onscreen = true;
+			currentframe = frame;			
+		}
+
+		void SysDeleteFrame(CPU::InterruptRegisters* R)
+		{
+			int fd = (int) R->ebx;
+
+			Process* process = CurrentProcess();
+			Device* device = process->descriptors.Get(fd);
+			process->descriptors.Free(fd);
+			
+			if ( device == NULL ) { R->eax = -1; return; }
+			if ( !device->Close() )  { R->eax = -1; return; }
+			R->eax = 0;
+		}
+	}
+
+	DevVGAFrame::DevVGAFrame()
+	{
+		process = NULL;
+		userframe = NULL;
+		physical = 0;
+		onscreen = false;
+	}
+
+	DevVGAFrame::~DevVGAFrame()
+	{
+		if ( process != NULL ) { ASSERT(CurrentProcess() == process); }
+		if ( userframe != NULL ) { VirtualMemory::UnmapUser((addr_t) userframe); }
+		if ( physical != 0 ) { Page::Put(physical); }
+	}
+
+	nat DevVGAFrame::Flags() { return Device::VGABUFFER; }
+}

sortix/vga.h

@@ -25,8 +25,12 @@
 #ifndef SORTIX_VGA_H
 #define SORTIX_VGA_H
 
+#include "device.h"
+
 namespace Sortix
 {
+	class Process;
+
 	namespace VGA
 	{
 		// TODO: Move these to a better place
@@ -55,7 +59,36 @@ namespace Sortix
 
 			uint16_t Data[80*25];
 		};
+
+		struct UserFrame : public Frame
+		{
+			int fd;
+		};
+
+		void Init();
+
+		// System Calls.
+		void SysCreateFrame(CPU::InterruptRegisters* R);
+		void SysChangeFrame(CPU::InterruptRegisters* R);
+		void SysDeleteFrame(CPU::InterruptRegisters* R);
 	}
+
+	class DevVGAFrame : public Device
+	{
+	public:
+		virtual nat Flags();
+
+	public:
+		DevVGAFrame();
+		~DevVGAFrame();
+
+	public:
+		Process* process;
+		addr_t physical;
+		VGA::UserFrame* userframe;
+		bool onscreen;
+
+	};
 }
 
 #endif