From d9c0c8d0cd0ebacb3b0413051dbd4647358a49da Mon Sep 17 00:00:00 2001
From: Jonas 'Sortie' Termansen <sortie@maxsi.org>
Date: Sat, 27 Aug 2011 17:41:35 +0200
Subject: [PATCH] Added a driver to parse the Sortix init ramdisk.

---
 sortix/Makefile   |  2 +-
 sortix/initrd.cpp | 69 +++++++++++++++++++++++++++++++++++++++++++++++
 sortix/initrd.h   |  5 ++++
 3 files changed, 75 insertions(+), 1 deletion(-)
 create mode 100644 sortix/initrd.cpp

diff --git a/sortix/Makefile b/sortix/Makefile
index 8a472b1d..77a23bea 100644
--- a/sortix/Makefile
+++ b/sortix/Makefile
@@ -44,7 +44,7 @@ DEFINES:=$(DEFINES) -DINITRD
 CPPFLAGSRELEASE=-s -O3
 CPPFLAGSDEBUG=
 CPPFLAGS=-I.. -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 vga.o elf.o process.o ../libmaxsi/libmaxsi-sortix.a
+OBJS=$(CPUOBJS) kernel.o descriptor_tables.o isr.o time.o log.o iprintable.o panic.o keyboard.o memorymanagement.o scheduler.o syscall.o application.o pong.o sound.o pci.o uart.o conway.o test.o http.o vgaterminal.o serialterminal.o descriptors.o device.o vga.o elf.o process.o initrd.o ../libmaxsi/libmaxsi-sortix.a
 JSOBJS:=$(subst .o,-js.o,$(OBJS))
 
 all: sortix.bin
diff --git a/sortix/initrd.cpp b/sortix/initrd.cpp
new file mode 100644
index 00000000..25f3f916
--- /dev/null
+++ b/sortix/initrd.cpp
@@ -0,0 +1,69 @@
+/******************************************************************************
+
+	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/>.
+
+	initrd.cpp
+	Declares the structure of the Sortix ramdisk.
+
+******************************************************************************/
+
+#include "platform.h"
+#include "initrd.h"
+#include <libmaxsi/string.h>
+
+#include "log.h" // DEBUG
+
+using namespace Maxsi;
+
+namespace Sortix
+{
+	namespace InitRD
+	{
+		byte* initrd;
+		size_t initrdsize;
+
+		void Init(byte* theinitrd, size_t size)
+		{
+			initrd = theinitrd;
+			initrdsize = size;
+			if ( size < sizeof(Header) ) { PanicF("initrd.cpp: initrd is too small"); }
+			Header* header = (Header*) initrd;
+			if ( String::Compare(header->magic, "sortix-initrd-1") != 0 ) { PanicF("initrd.cpp: invalid magic value in the initrd"); }
+			size_t sizeneeded = sizeof(Header) + header->numfiles * sizeof(FileHeader);
+			if ( size < sizeneeded ) { PanicF("initrd.cpp: initrd is too small"); }
+			// TODO: We need to do more validation here!
+		}
+
+		byte* Open(const char* filepath, size_t* size)
+		{
+			Header* header = (Header*) initrd;
+			FileHeader* fhtbl = (FileHeader*) (initrd + sizeof(Header));
+			for ( uint32_t i = 0; i < header->numfiles; i++ )
+			{
+				FileHeader* fileheader = &(fhtbl[i]);
+
+				if ( String::Compare(filepath, fileheader->name) != 0 ) { continue; }
+
+				*size = fileheader->size;
+				return initrd + fileheader->offset;
+			}
+
+			return NULL;
+		}
+	}
+}
diff --git a/sortix/initrd.h b/sortix/initrd.h
index 39171156..5a826a9a 100644
--- a/sortix/initrd.h
+++ b/sortix/initrd.h
@@ -48,6 +48,11 @@ namespace Sortix
 			uint32_t offset; // where the physical data is located.
 			char name[128];
 		};
+
+#ifdef SORTIX_KERNEL
+		void Init(byte* initrd, size_t size);
+		byte* Open(const char* filepath, size_t* size);
+#endif
 	}
 }