total failure

Makefile

@@ -1,12 +1,16 @@
 
-all: mtgos
+all: mtgos user
 
 mtgos:
 	make -C kernel
 	mv kernel/mtgos mtgos
 
+user:
+	make -C user
+	mv user/*.elf .
+
 clean:
 	make -C kernel clean
 	rm -rf mtgos
 
-.PHONY: all mtgos clean
+.PHONY: all mtgos user clean

kernel/hal/x86/init/init.cpp

@@ -10,7 +10,7 @@
 #include <blockdev.hpp>
 #include <pmm.hpp>
 extern "C" void intr_stub_0(void);
-void main();
+void main(void ** programs);
 namespace MTGosHAL {
 	Serial debug;
 	Screen out;
@@ -44,7 +44,17 @@ namespace MTGosHAL {
 		idt.setEntry(8, (void *)((uint32_t)&intr_stub_0+128), SEG_DBL_FAULT, IDT_TASK_GATE | IDT_SEG_32_BIT | IDT_RING_0 | IDT_USED);
 		idt.apply();
 		mm.init(ebx);
-		::main();
+		multiboot_mod_list *mods = (multiboot_mod_list*) ebx->mods_addr;
+		void** progs=nullptr;
+		void* tmp;
+		mm >> tmp;
+		progs=(void**)tmp;
+		uint32_t i;
+		for(i=0;i<(ebx->mods_count<1023?ebx->mods_count:1023);i++) { //Basically until MIN(ebx->mods_count, 1023), as we only support loading up to 1023 programs directly.
+			progs[i]=(void*)(mods[i].mod_start);
+		}
+		progs[i]=nullptr;
+		::main(progs);
 		sti();
 		for(;;);
 	}

kernel/hal/x86/mm/pmm.cpp

@@ -57,6 +57,13 @@ auto PMM::init(struct multiboot_info * mb_info) -> void {
 		addr+=0x1000;
 	}
 	markUsed(nullptr);
+	multiboot_mod_list *mods = (multiboot_mod_list*) mb_info->mods_addr;
+	for(uint32_t i=0;i<mb_info->mods_count;i++) {
+		markUsed((void*)((uint32_t)(&mods[i])&(~0xFFF))); //Mark all of the module table as used
+		for(uint32_t start=(uint32_t)(mods[i].mod_start)&(~0xFFF);start<(uint32_t)(mods[i].mod_end);start+=0x1000) {
+			markUsed((void*)start); //Protect all multiboot modules
+		}
+	}
 }
 auto PMM::markUsed(void * addr) -> void {
 	unsigned int address=(unsigned int)addr;

kernel/kernel/elf.cpp

@@ -0,0 +1,16 @@
+#include <elf.hpp>
+auto load(Elf32_Ehdr* file) -> void* {
+  if((file->e_ident[0]!=ELFMAG0)||
+     (file->e_ident[1]!=ELFMAG1)||
+     (file->e_ident[2]!=ELFMAG2)||
+     (file->e_ident[3]!=ELFMAG3) )
+    return nullptr;
+  Elf32_Phdr *phdr = (Elf32_Phdr*)((uint32_t)(file->e_phoff)+(uint32_t)file);
+  for(int i=0;i<file->e_phnum;i++) {
+    uint32_t start=phdr[i].p_vaddr;
+    uint32_t end=start+phdr[i].p_memsz;
+    if((start < file->e_entry) && (file->e_entry < end))
+      return (void*) (file->e_entry-start+phdr[i].p_offset+(uint32_t)file); //Calculate _start address
+  }
+  return nullptr;
+}

kernel/kernel/include/elf.hpp

@@ -0,0 +1,2 @@
+#include <elf.h>
+auto load(Elf32_Ehdr* file) -> void*;

kernel/kernel/init.cpp

@@ -5,6 +5,7 @@
 #include <keyboard.hpp>
 #include <Multitasking.h>
 #include <blockdev.hpp>
+#include <elf.hpp>
 using namespace MTGosHAL;
 void pid_null() {
   for(;;);
@@ -25,11 +26,14 @@ void task_d() {
   while(true)
     MTGosHAL::out << "d";
 }
-void main() {
-    MTGosHAL::out << "Initializing Kernel!\n";
-    MTGosHAL::tasks.initTask(&pid_null);
-    MTGosHAL::tasks.initTask(&task_a);
-    MTGosHAL::tasks.initTask(&task_b);
-    MTGosHAL::tasks.initTask(&task_c);
-    MTGosHAL::tasks.initTask(&task_d);
+void main(void** files) {
+  MTGosHAL::out << "Initializing Kernel!\n";
+  Elf32_Ehdr** programs=(Elf32_Ehdr**)files;
+  MTGosHAL::tasks.initTask(&pid_null);
+  for(int i=0;programs[i];i++) {
+    void(*start)()=(void(*)())load(programs[i]);
+    if(!start)
+      continue;
+    MTGosHAL::tasks.initTask(start);
+  }
 }

user/Makefile

@@ -0,0 +1,17 @@
+include ../kernel.settings
+SRCS = $(shell find -name '*.c')
+OBJS = $(addsuffix .o,$(basename $(SRCS)))
+CC = $(PREFIX)gcc
+LD = $(PREFIX)ld
+ASFLAGS = -m32
+CFLAGS = -m32 -w -g -fno-stack-protector -nostdinc -I include -fpie
+LDFLAGS = -melf_i386 -Ttest.ld
+test.elf: $(OBJS)
+		$(LD) $(LDFLAGS) -o $@ $^
+
+%.o: %.c
+		$(CC) $(CFLAGS) -c -o $@ $^
+
+clean:
+		rm $(OBJS)
+.PHONY: clean

user/test.c

@@ -0,0 +1,11 @@
+unsigned short* videomem = (unsigned short*) 0xb8000;
+
+void _start(void)
+{
+    int i;
+    for (i = 0; i < 3; i++) {
+        *videomem++ = (0x07 << 8) | ('0' + i);
+    }
+
+    while(1);
+}

user/test.ld

@@ -0,0 +1,28 @@
+ENTRY(_start)
+OUTPUT_FORMAT(elf32-i386)
+SECTIONS
+{
+  . = 0x0;
+  .text : {
+    *(.text)
+  }
+  .data ALIGN(4096) : {
+		start_ctors = .;
+			KEEP(*( .init_array ));
+			KEEP(*(SORT_BY_INIT_PRIORITY( .init_array.* )));
+			*(.ctors)
+		end_ctors = .;
+		start_dtors = .;
+			*(.dtors)
+		end_dtors = .;
+		*(.data)
+    *(.got)
+	}
+	.rodata ALIGN(4096) : {
+		*(.rodata)
+	}
+	.bss ALIGN(4096) : {
+		*(.bss)
+	}
+	. = ALIGN(4096);
+}