Adds ELF loader to init.cpp

prototypes/base/Makefile

@@ -6,7 +6,7 @@ LD=ld
 
 IDT_DISPATCH = _ZN3IDT8dispatchEP8CpuState
 
-FLAGS = -mno-sse -DIDT_DISPATCH=$(IDT_DISPATCH) -ffreestanding -m32 -Werror -Wall -iquote include -iquote lists -O3 -g
+FLAGS = -mno-sse -DIDT_DISPATCH=$(IDT_DISPATCH) -ffreestanding -m32 -Werror -Wall -iquote include -iquote lists -I../stdlib/include  -O3 -g
 ASFLAGS = $(FLAGS)
 CFLAGS = $(FLAGS)	
 CXXFLAGS = $(FLAGS) -std=c++14 -fno-rtti -fno-exceptions -fno-leading-underscore -fno-use-cxa-atexit -nostdlib -fno-builtin
@@ -15,11 +15,12 @@ SRCS = $(shell find -regextype egrep -regex '.*/.*\.(cpp|S|c)')
 OBJS = $(addsuffix .o, $(notdir $(basename $(SRCS))))
 
 LIBGCC = $(shell gcc -m32 -print-libgcc-file-name)
+LIBSTD = ../stdlib/libstd.a
 
 all: kernel-base.ker
 
 kernel-base.ker: $(OBJS)
-	$(LD) -melf_i386 -Tlinker.ld -o kernel-base.ker $(addprefix obj/, $^) $(LIBGCC) 
+	$(LD) -melf_i386 -Tlinker.ld -o kernel-base.ker $(addprefix obj/, $^) $(LIBGCC) $(LIBSTD)
 
 %.o: %.cpp
 	$(CXX) $(CXXFLAGS) -c -o obj/$@ $<
@@ -54,7 +55,7 @@ run:
 		-no-reboot \
 		-no-shutdown \
 		-serial stdio \
-		-initrd ../program0/program0.bin 
+		-initrd ../program0/program 
 
 insight:
 	objdump -d kernel-base.ker | c++filt | less

prototypes/base/include/elf.hpp

@@ -0,0 +1,36 @@
+#pragma once
+
+#include <inttypes.h>
+
+namespace elf
+{
+	static const uint32_t MAGIC = 0x464C457F;
+	 
+	struct Header {
+		uint32_t    magic;
+		uint32_t    version;
+		uint64_t    reserved;
+		uint64_t    version2;
+		uint32_t    entry;
+		uint32_t    ph_offset;
+		uint32_t    sh_offset;
+		uint32_t    flags;
+		uint16_t    header_size;
+		uint16_t    ph_entry_size;
+		uint16_t    ph_entry_count;
+		uint16_t    sh_entry_size;
+		uint16_t    sh_entry_count;
+		uint16_t    sh_str_table_index;
+	} __attribute__((packed));
+
+	struct ProgramHeader {
+		uint32_t    type;
+		uint32_t    offset;
+		uint32_t    virt_addr;
+		uint32_t    phys_addr;
+		uint32_t    file_size;
+		uint32_t    mem_size;
+		uint32_t    flags;
+		uint32_t    alignment;
+	} __attribute__((packed));
+}

prototypes/base/init.cpp

@@ -8,6 +8,8 @@
 #include "compat.h"
 #include "io.hpp"
 #include "vmm.hpp"
+#include "elf.hpp"
+#include "bsod.hpp"
 
 #include "driver/timer.hpp"
 #include "driver/keyboard.hpp"
@@ -16,6 +18,8 @@
 #include <inttypes.h>
 #include <new>
 
+#include <string.h>
+
 using namespace multiboot;
 using namespace console_tools;
 
@@ -31,26 +35,76 @@ driver::Scheduler scheduler;
 
 VMMContext *kernelContext;
 
+static const uint32_t entryPointAddress = 0x40000000;
+
 void run_program0(Module const & module)
 {
-	for(uint32_t ptr = 0; ptr < module.size(); ptr += 0x1000)
-	{
+	using namespace elf;
+	
+	const Header *header = module.start.data<elf::Header>();
+	
+	ProgramHeader *ph;
+	int i;
+	if (header->magic != MAGIC) {
+		BSOD::die(Error::InvalidELFImage, "Keine gueltige ELF-Magic!\n");
+		return;
+	}
+
+	ph = (ProgramHeader*)(((char*) header) + header->ph_offset);
+	for (i = 0; i < header->ph_entry_count; i++, ph++) {
+		void* dest = (void*) ph->virt_addr;
+		void* src = ((char*) header) + ph->offset;
+
+		/* Nur Program Header vom Typ LOAD laden */
+		if (ph->type != 1) {
+			continue;
+		}
+		
+		if(ph->virt_addr < entryPointAddress) {
+			BSOD::die(Error::InvalidELFImage, "A LOAD section tried to sneak into the kernel!");
+		}
+
+		for(uint32_t i = 0; i < ph->mem_size; i += 0x1000) {
 			kernelContext->provide(
-			virtual_t(0x40000000 + ptr),
+				virtual_t(ph->virt_addr + i),
 				VMMFlags::Writable | VMMFlags::UserSpace);
 		}
-	char * src = module.start.data<char>();
-	char * dst = (char*)0x40000000;
-	for(uint32_t ptr = 0; ptr < module.size(); ptr++)
-	{
-		dst[ptr] = src[ptr];
+		
+		memset(dest, 0, ph->mem_size);
+		memcpy(dest, src, ph->file_size);
 	}
 	
 	using EntryPoint = void (*)();
-	EntryPoint ep = (EntryPoint)0x40000000;
+	EntryPoint ep = (EntryPoint)entryPointAddress;
 	ep();
 }
 
+static void dump_elf(elf::Header *header)
+{
+	using namespace elf;
+	ProgramHeader *ph;
+	int i;
+
+	/* Ist es ueberhaupt eine ELF-Datei? */
+	if (header->magic != MAGIC) {
+		BSOD::die(Error::InvalidELFImage, "Keine gueltige ELF-Magic!\n");
+		return;
+	}
+	ph = (ProgramHeader*)(((char*) header) + header->ph_offset);
+	for (i = 0; i < header->ph_entry_count; i++, ph++) {
+		void* dest = (void*) ph->virt_addr;
+		void* src = ((char*) header) + ph->offset;
+
+		Console::main
+			<< "Header: "   << ph->type << ", "
+			<< "Source: "   << src  << ", "
+			<< "Dest: "     << dest << ", "
+			<< "Memsize: "  << ph->mem_size << ", "
+			<< "Filesize: " << ph->file_size 
+			<< "\n";
+	}
+}
+
 extern "C" void init(Structure const & data)
 {
 	Console::main
@@ -154,6 +208,8 @@ extern "C" void init(Structure const & data)
 	
 	if(data.modules.length > 0)
 	{
+		Console::main << "ELF Modukle:\n";
+		dump_elf(data.modules[0].start.data<elf::Header>());
 		run_program0(data.modules[0]);
 	}
 	

prototypes/base/lists/errors.lst

@@ -3,3 +3,4 @@ ERROR(1, OutOfMemory,            The system has run out of memory.)
 ERROR(2, UnhandledException,     An unhandled exception has occurred.)
 ERROR(3, UnhandledInterrupt,     An unhandled interrupt has occurred.)
 ERROR(4, DriverAlreadyInstalled, A driver was already installed.)
+ERROR(5, InvalidELFImage,        The file beeing loaded is not a valid ELF file.)