1 files changed, 35 insertions, 42 deletions

diff --git a/source/elf_load.cpp b/source/elf_load.cpp
index 161bd7e..3fd8a0f 100644
--- a/source/elf_load.cpp
+++ b/source/elf_load.cpp
@@ -4,6 +4,8 @@
 #include <algorithm>
 #include <cstring>
 
+//constexpr unsigned int ELF_LOAD_ADDR = 0x10000000;
+
 static const unsigned char elf_header[] = { '\177', 'E', 'L', 'F' };
 
 template<typename T>
@@ -12,67 +14,58 @@ constexpr static auto ptr_from_offset(void *base, uint32_t offset)
     return reinterpret_cast<T>(reinterpret_cast<uint8_t *>(base) + offset);
 }
 
-static Elf32_Shdr *find_section(Elf32_Ehdr *ehdr, const char *name);
+//static Elf32_Shdr *find_section(Elf32_Ehdr *ehdr, const char *name);
 
 namespace elf {
 
-entry_t load(void *elf_data, void *elf_load_offset)
+entry_t load(void *elf_data)
 {
+    // Check the ELF's header signature
     auto ehdr = reinterpret_cast<Elf32_Ehdr *>(elf_data);
     if (!std::equal(ehdr->e_ident, ehdr->e_ident + 4, elf_header))
         return nullptr;
 
+    // Iterate through program header LOAD sections
+    bool loaded = false;
     auto phdr = ptr_from_offset<Elf32_Phdr *>(elf_data, ehdr->e_phoff);
     for (Elf32_Half i = 0; i < ehdr->e_phnum; i++) {
         if (phdr->p_type == PT_LOAD) {
-            std::memcpy(ptr_from_offset<void *>(elf_load_offset, phdr->p_vaddr),
-                        ptr_from_offset<void *>(elf_data, phdr->p_offset),
-                        phdr->p_filesz);
-            //break;
+            if (phdr->p_filesz == 0) {
+                std::memset(reinterpret_cast<void *>(phdr->p_vaddr),
+                            0,
+                            phdr->p_memsz);
+            } else {
+                std::memcpy(reinterpret_cast<void *>(phdr->p_vaddr),
+                            ptr_from_offset<void *>(elf_data, phdr->p_offset),
+                            phdr->p_filesz);
+                if (!loaded)
+                    loaded = true;
+            }
         }
 
         phdr = ptr_from_offset<Elf32_Phdr *>(phdr, ehdr->e_phentsize);
     }
 
-    // Zero .bss section
-    if (auto bss_section = find_section(ehdr, ".bss"); bss_section) {
-        auto bss = ptr_from_offset<uint32_t *>(elf_load_offset, bss_section->sh_addr);
-        std::fill(bss, bss + bss_section->sh_size / sizeof(uint32_t), 0);
-    }
-
-    // Fix global offset table (GOT) entries
-    if (auto got_section = find_section(ehdr, ".got"); got_section) {
-        auto got = ptr_from_offset<void **>(elf_load_offset, got_section->sh_addr);
-        for (size_t i = 0; i < got_section->sh_size / sizeof(void *); i++)
-            got[i] = ptr_from_offset<void *>(got[i], reinterpret_cast<uint32_t>(elf_load_offset));
-    }
-
-    //// Run any initial constructors
-    //if (auto init_section = find_section(ehdr, ".init_array"); init_section) {
-    //    auto init_array = reinterpret_cast<void (**)()>(elf_load_offset + init_section->sh_addr);
-    //    std::for_each(init_array, init_array + init_section->sh_size / sizeof(void (*)()),
-    //                  [elf_load_offset](auto func) { (func + elf_load_offset)(); });
-    //}
 
-    return ptr_from_offset<entry_t>(elf_load_offset, ehdr->e_entry);
+    return loaded ? reinterpret_cast<entry_t>(ehdr->e_entry) : nullptr;
 }
 
 } // namespace elf
 
-Elf32_Shdr *find_section(Elf32_Ehdr *ehdr, const char *name)
-{
-    auto shdr = ptr_from_offset<Elf32_Shdr *>(ehdr, ehdr->e_shoff);
-    auto shdr_str = ptr_from_offset<Elf32_Shdr *>(ehdr,
-        ehdr->e_shoff + ehdr->e_shstrndx * ehdr->e_shentsize);
-
-    for (Elf32_Half i = 0; i < ehdr->e_shnum; i++) {
-        char *section = ptr_from_offset<char *>(ehdr, shdr_str->sh_offset) + shdr->sh_name;
-        if (!strcmp(section, name))
-            return shdr;
-
-        shdr = ptr_from_offset<Elf32_Shdr *>(shdr, ehdr->e_shentsize);
-    }
-
-    return 0;
-}
+//Elf32_Shdr *find_section(Elf32_Ehdr *ehdr, const char *name)
+//{
+//    auto shdr = ptr_from_offset<Elf32_Shdr *>(ehdr, ehdr->e_shoff);
+//    auto shdr_str = ptr_from_offset<Elf32_Shdr *>(ehdr,
+//        ehdr->e_shoff + ehdr->e_shstrndx * ehdr->e_shentsize);
+//
+//    for (Elf32_Half i = 0; i < ehdr->e_shnum; i++) {
+//        char *section = ptr_from_offset<char *>(ehdr, shdr_str->sh_offset) + shdr->sh_name;
+//        if (!strcmp(section, name))
+//            return shdr;
+//
+//        shdr = ptr_from_offset<Elf32_Shdr *>(shdr, ehdr->e_shentsize);
+//    }
+//
+//    return 0;
+//}