Added somewhat working dynamic lib/.so file loading

source/includes/executables/elf.h

@@ -10,44 +10,4 @@
  */
 #include <basics.h>
 
-#define elf_magic 0x464C457F // 0x7F, then 'ELF' in ASCII 
-
-typedef struct {
-    int32 magic;
-    int8  _class;
-    int8  data;
-    int8  version;
-    int8  osabi;
-    int8  abiversion;
-    int8  pad[7];
-    int16 type;
-    int16 machine;
-    int32 version_elf;
-    int64 entry;
-    int64 ph_offset;
-    int64 sh_offset;
-    int32 flags;
-    int16 header_size;
-    int16 ph_entry_size;
-    int16 ph_num;
-    int16 sh_entry_size;
-    int16 sh_num;
-    int16 sh_str_index;
-} elf_x64_header;
-
-/**
- * @brief Unused yet!
- * 
- */
-typedef struct {
-    int32 type;
-    int32 flags;
-    int64 offset;
-    int64 vaddr;
-    int64 paddr;
-    int64 filesz;
-    int64 memsz;
-    int64 align;
-} elf_x64_program_header;
-
-void execute_elf(int64* address);
+void* elf_load_from_memory(void* file_base_address);

source/includes/fdlfcn.h

@@ -0,0 +1,31 @@
+#ifndef __FDLFCN_H_
+#define __FDLFCN_H_ 1
+
+#include <elf.h>
+
+typedef struct
+{
+    void* address;
+    Elf64_Ehdr ehdr;
+    Elf64_Shdr* shdrs;
+    Elf64_Sym* symbols;
+    Elf64_Rela* relocations;
+
+    int symtab_index;
+    void* text_section_data;
+    void* data_section_data;
+    void* rodata_section_data;
+
+    Elf64_Shdr* text_section_header;
+    Elf64_Shdr* data_section_header;
+    Elf64_Shdr* rodata_section_header;
+} fdlfcn_handle;
+
+// immediately load sections into memory
+#define FDL_IMMEDIATE 0
+
+fdlfcn_handle* fdlopen(void* filedata, int flags);
+void* fdlsym(fdlfcn_handle* handle, const char* symbol_name);
+int fdlclose(fdlfcn_handle* handle);
+
+#endif

source/includes/kernel.h

@@ -41,6 +41,7 @@
 #include <ps2-mouse.h>
 #include <image/targa.h>
 #include <executables/fwde.h>
+#include <fdlfcn.h>
 
 /**
  * @brief The memory address pointer where the kernel ends.

source/kernel/C/executables/elf.c

@@ -9,16 +9,46 @@
  * 
  */
 #include <executables/elf.h>
+#include <memory2.h>
+#include <stdint.h>
+#include <heap.h>
+#include <elf.h>
 
-void execute_elf(int64* address) {
-    elf_x64_header *header = (elf_x64_header*)address;
-
-    if (header->magic != elf_magic) {
-        error("Not a valid ELF file to load!", __FILE__);
+void elf_load_program_header(Elf64_Phdr* program_header, void* file_base_addr)
+{
+    if (program_header == NULL)
         return;
+
+    Elf64_Word type = program_header->p_type;
+    printf("Program Header type: %x", type);
+}
+
+void* elf_load_from_memory(void* file_base_address)
+{
+    if (file_base_address == NULL)
+        return NULL;
+
+    uint8_t* file_ptr = file_base_address;
+    Elf64_Ehdr header = {};
+    memcpy(&header, file_ptr, sizeof(Elf64_Ehdr));
+
+    if (memcmp(&header.e_ident[EI_MAG0], ELFMAG, SELFMAG) != 0 || header.e_ident[EI_CLASS] != ELFCLASS64 ||
+        header.e_ident[EI_DATA] != ELFDATA2LSB || header.e_type != ET_EXEC ||
+        header.e_machine != EM_X86_64 || header.e_version != EV_CURRENT)
+    {
+        error("Not a valid ELF file to load!", __FILE__);
+        return NULL;
     }
 
-    void (*entry_point)() = (void (*)(void)) (int64*)&header->entry;
+    printf("Parsing ELF64 file with %d PHDRs\n", header.e_phnum);
+    file_ptr = file_ptr + header.e_phoff;
+    size_t program_headers_size = header.e_phnum * header.e_phentsize;
+    Elf64_Phdr* program_headers_start = (Elf64_Phdr*)file_ptr;
+    Elf64_Phdr* program_headers_end = (Elf64_Phdr*)(file_ptr + program_headers_size);
+    for (Elf64_Phdr* prog_header = program_headers_start;
+         (uint8_t*)prog_header < program_headers_end;
+         prog_header = (Elf64_Phdr*)(((uint8_t*)prog_header + header.e_phentsize)))
+        elf_load_program_header(prog_header, file_base_address);
 
-    entry_point();
+    return (void*)header.e_entry;
 }