Added load_program() function

Builds program image from ELF file in memory
Fixed multiple definition error caused by constant in elf.h:
moved contant to elf.c

src/elf.c

@@ -0,0 +1,40 @@
+#include "elf.h"
+#include "pageallocator.h"
+#include "mmgr.h"
+#include "string.h"
+#include "types/status.h"
+
+const uint32_t elf_magic_number = 0x464c457f;
+
+int load_program(struct elf_file_header_t *elf, struct page_stack_t *page_stack)
+{
+    struct elf_program_header_t *program_header = (struct elf_program_header_t*)((void*)elf + elf->phoffset);
+    unsigned int count = elf->phcount;
+    while(count > 0)
+    {
+        if(program_header->type == ELF_LOAD)
+        {
+            void *d = program_header->vaddr, *s = (void*)elf + program_header->offset;
+            for(size_t n = 0; n < program_header->memsize; n += page_size)
+            {
+                physaddr_t page = reserve_page(page_stack);
+                if(page == S_OUT_OF_MEMORY)
+                {
+                    return S_OUT_OF_MEMORY;
+                }
+                int status = map_page(page_stack, d, page, PAGE_RW | PAGE_USERMODE | PAGE_EXECUTABLE);
+                switch(status)
+                {
+                case S_OUT_OF_MEMORY:
+                    return status;
+                case S_OUT_OF_BOUNDS:
+                    return status;
+                case S_OK:
+                    memcpy(d, s, page_size);
+                }
+            }
+        }
+        count--;
+        program_header = (struct elf_program_header_t*)((void*)program_header + elf->phsize);
+    }
+}