diff --git a/src/common.h b/src/common.h
index f6282ea..9fa02f1 100644
--- a/src/common.h
+++ b/src/common.h
@@ -7,6 +7,7 @@
 static inline u32 has_mask(u32 flags, u32 mask) { return flags & mask; }
 
 #define MIN(A, B) ((A) < (B) ? (A) : (B))
+#define MAX(A, B) ((A) > (B) ? (A) : (B))
 #define ARRLEN(A) (sizeof((A)) / (sizeof((A)[0])))
 
 #endif // COMMON_H_
diff --git a/src/files.c b/src/files.c
index a55aafe..ef870e8 100644
--- a/src/files.c
+++ b/src/files.c
@@ -2,7 +2,14 @@
 
 #include "logger/logger.h"
 #include "string/string.h"
+#include "types.h"
 
+#include <errno.h>
+#include <sys/stat.h>
+
+#ifndef HI_FILE_BUFFER_SIZE
+#define HI_FILE_BUFFER_SIZE 4096
+#endif
 
 char *hi_file_to_str_dyn(const char *filename) {
 
@@ -14,3 +21,119 @@ char *hi_file_to_str_dyn(const char *filename) {
   return s;
 }
 
+HiFileType hi_file_interpret_as_type(const char *path) {
+  const char *pathname_end = path + strlen(path);
+  char last_char = *(pathname_end - 1);
+  bool as_dir = (last_char == '/') || (last_char == '\\');
+  return as_dir ? HI_FILE_TYPE_DIR : HI_FILE_TYPE_FILE;
+}
+
+const char *hi_file_name_from_path(const char *path) {
+  const char *filename = path;
+
+  // Find the last directory separator
+  const char *last_slash = strrchr(path, '/');
+  const char *last_backslash = strrchr(path, '\\');
+
+  // Determine which separator was found last (if any)
+  if (last_slash && (!last_backslash || last_slash > last_backslash)) {
+    filename = last_slash + 1;
+  } else if (last_backslash) {
+    filename = last_backslash + 1;
+  }
+
+  return filename;
+}
+
+HiloadResult hi_file_copy(const char *srcname, const char *destination) {
+
+  HiloadResult ret = HILOAD_FAIL;
+
+  FILE *src = fopen(srcname, "rb");
+  if (src == NULL) {
+    log_error("Couldn't open file: %s for copy\n", srcname);
+    return HILOAD_FAIL;
+  }
+
+  char buf[512];
+
+  const char *dstname = destination;
+
+  HiFileType dst_type = hi_file_interpret_as_type(destination);
+  if (dst_type == HI_FILE_TYPE_DIR) {
+    hi_strncat_buf(sizeof(buf), buf, destination,
+                   hi_file_name_from_path(srcname));
+    dstname = buf;
+  }
+
+  FILE *dst = fopen(dstname, "wb");
+  if (dst == NULL) {
+    log_error("Failed to open destination: %s\n", dstname);
+    goto cleanup;
+  }
+
+  char buffer[HI_FILE_BUFFER_SIZE];
+  size_t bytes_read = 0;
+  while ((bytes_read = fread(buffer, 1, sizeof buffer, src)) > 0) {
+    if (fwrite(buffer, 1, bytes_read, dst) != bytes_read) {
+      log_error("Error writing to destination: %s\n", dstname);
+      goto cleanup;
+    }
+  }
+
+  if (ferror(src)) {
+    log_error("Error reading from source: %s\n");
+    goto cleanup;
+  }
+
+  ret = HILOAD_OK;
+
+cleanup:
+  if (src) fclose(src);
+  if (dst) fclose(dst);
+
+  return ret;
+}
+
+/**
+ * Check file type from path.
+ *
+ * TAG: posix
+ */
+HiFileType hi_file_type(const char *path) {
+  struct stat path_stat;
+  int err = stat(path, &path_stat);
+  if (err == -1) {
+    if (errno == ENOENT) {
+      // Doesn't exist, don't count as error
+      return HI_FILE_TYPE_NONE;
+    }
+    log_error("Opening file failed: %s\n", strerror(errno));
+    return HI_FILE_TYPE_NONE;
+  }
+
+  if (S_ISREG(path_stat.st_mode)) {
+    return HI_FILE_TYPE_FILE;
+  }
+  if (S_ISDIR(path_stat.st_mode)) {
+    return HI_FILE_TYPE_DIR;
+  }
+  if (S_ISCHR(path_stat.st_mode)) {
+    return HI_FILE_TYPE_CHR;
+  }
+  if (S_ISBLK(path_stat.st_mode)) {
+    return HI_FILE_TYPE_BLK;
+  }
+  if (S_ISFIFO(path_stat.st_mode)) {
+    return HI_FILE_TYPE_FIFO;
+  }
+  if (S_ISLNK(path_stat.st_mode)) {
+    return HI_FILE_TYPE_LNK;
+  }
+  if (S_ISSOCK(path_stat.st_mode)) {
+    return HI_FILE_TYPE_SOCK;
+  }
+
+  return HI_FILE_TYPE_NONE;
+}
+
diff --git a/src/files.h b/src/files.h
index cffb46e..6064d91 100644
--- a/src/files.h
+++ b/src/files.h
@@ -1,6 +1,21 @@
 #ifndef FILES_H_
 #define FILES_H_
 
+#include "types.h"
+
+typedef enum {
+  HI_FILE_TYPE_FILE = 0,
+  HI_FILE_TYPE_DIR,
+  HI_FILE_TYPE_CHR,
+  HI_FILE_TYPE_BLK,
+  HI_FILE_TYPE_FIFO,
+  HI_FILE_TYPE_LNK,
+  HI_FILE_TYPE_SOCK,
+
+  HI_FILE_TYPE_COUNT,
+  HI_FILE_TYPE_NONE,
+} HiFileType;
+
 /**
  * Read file dynamically to a string
  *
@@ -8,7 +23,19 @@
  * with no size. The realistic optimum case contains two allocations, one for
  * the initial memory and a reallocation to match the string size.
  */
+
 char *hi_file_to_str_dyn(const char *filename);
 
+/**
+ * Copy file \p filename to \p dest
+ *
+ * If \p dest has either '/' or '\' as the last character, it is interpreted as
+ * a directory and the file is copied to the directory with the same filename.
+ */
+HiloadResult hi_file_copy(const char *filename, const char *dest);
+
+HiFileType hi_file_type(const char *path);
+
+const char *hi_file_name_from_path(const char *path);
 
 #endif // FILES_H_
diff --git a/src/hiload.c b/src/hiload.c
index e2160b5..b8abac0 100644
--- a/src/hiload.c
+++ b/src/hiload.c
@@ -211,6 +211,7 @@ int hi_init(unsigned n, const char **enabled_modules) {
     sc_array_add(&context.enabled_modules, module_name);
   }
 
+  sc_array_init(&context.memory_regions);
   if (read_memory_maps_self(&context.memory_regions) != HILOAD_OK) {
     log_error("Could not populate program memory maps.\n");
     return HILOAD_FAIL;
diff --git a/src/memory.c b/src/memory.c
index c1a4809..5995a51 100644
--- a/src/memory.c
+++ b/src/memory.c
@@ -31,8 +31,7 @@ HiloadResult memory_find_region(uptr ptr, struct sc_array_memreg *const regions,
 }
 
 HiloadResult read_memory_maps_self(struct sc_array_memreg *regions) {
-  sc_array_clear(regions);
-  sc_array_init(regions);
+  memory_clear_memregs(regions);
 
   char *maps_str = hi_file_to_str_dyn("/proc/self/maps");
   if (!maps_str)
@@ -103,10 +102,31 @@ memory_get_module_span(const struct sc_array_memreg *const regions,
       }
     } else {
       // we passed the module regions
-      if (end > 0) break;
+      if (end > 0)
+        break;
     }
   }
 
   assert(start < ~0ull && end > 0);
-  return  (MemoryRegionSpan){.region_start = start, .region_end = end};
+  return (MemoryRegionSpan){.region_start = start, .region_end = end};
+}
+
+void memory_clear_memregs(struct sc_array_memreg *regions) {
+  for (size_t i = 0; i < sc_array_size(regions); i++) {
+    memory_free_memreg(&sc_array_at(regions, i));
+  }
+  sc_array_clear(regions);
+}
+
+void memory_term_memregs(struct sc_array_memreg *regions) {
+  for (size_t i = 0; i < sc_array_size(regions); i++) {
+    memory_free_memreg(&sc_array_at(regions, i));
+  }
+  sc_array_term(regions);
+}
+
+void memory_free_memreg(MemoryRegion *reg) {
+  if (reg) {
+    free((char *)reg->pathname);
+  }
 }
diff --git a/src/memory.h b/src/memory.h
index bf4a042..349fe52 100644
--- a/src/memory.h
+++ b/src/memory.h
@@ -27,9 +27,15 @@ typedef struct {
   const char *pathname;
   u32 permission; // enum MemoryPermissions
 } MemoryRegion;
-
 sc_array_def(MemoryRegion, memreg);
 
+// Free memory and init to zero
+void memory_term_memregs(struct sc_array_memreg *regions);
+// Doesn't free underlying array memory, only for each region
+void memory_clear_memregs(struct sc_array_memreg *regions);
+// Free child memory
+void memory_free_memreg(MemoryRegion *reg);
+
 /* A pointer that can be used to place the memory regions into. Clears regions
  * before use, but uses the same buffer. */
 HiloadResult read_memory_maps_self(struct sc_array_memreg *regions);
diff --git a/src/moduler/elf.c b/src/moduler/elf.c
index 7fa4c83..3f697bd 100644
--- a/src/moduler/elf.c
+++ b/src/moduler/elf.c
@@ -7,18 +7,14 @@
 #include <libelf.h>
 #include <unistd.h>
 
-void *hi_elf_load_module(const char *filename) {
-  int fd = open(filename, O_RDONLY);
-
-  Elf *elf = elf_begin(fd, ELF_C_READ, NULL);
+void *hi_elf_load_module(void *address, size_t n) {
 
+  Elf *elf = elf_memory(address, n);
   Elf_Kind modkind = elf_kind(elf);
   log_debug("kind: %u\n", modkind);
 
-  uptr modbase = elf_getbase(elf);
-
-  close(fd);
-  return (void*)modbase;
+  elf_end(elf);
+  return address;
 }
 
 void hi_elf_print_module_from_memory(void *address, size_t size) {
@@ -36,7 +32,7 @@ void hi_elf_print_module_from_memory(void *address, size_t size) {
 
   for (size_t i = 0; i < phdrnum; ++i) {
     Elf64_Phdr *p = phdr + i;
-    log_debugv("segment type: %s\n", segment_type_to_str(p->p_type));
+    log_debug("segment type: %s\n", segment_type_to_str(p->p_type));
 
     size_t segment_size = p->p_memsz;
     void *segment_start = address + p->p_vaddr;
@@ -57,7 +53,7 @@ void hi_elf_print_module_from_memory(void *address, size_t size) {
     if (p->p_type == PT_DYNAMIC) {
       Elf64_Dyn *dyn = (Elf64_Dyn *)segment_start;
       while ((void *)dyn < segment_end) {
-        log_debugv("  dyn type: %s\n", dyn_type_to_str(dyn->d_tag));
+        log_debug("  dyn type: %s\n", dyn_type_to_str(dyn->d_tag));
 
         if (dyn->d_tag == DT_STRTAB) {
           strtab = (void *)dyn->d_un.d_ptr;
@@ -84,7 +80,7 @@ void hi_elf_print_module_from_memory(void *address, size_t size) {
         }
         ++dyn;
       }
-      log_debugv("\nstrtab: %p\n"
+      log_debug("\nstrtab: %p\n"
                  "symtab: %p\n"
                  "strsz: %zu\n"
                  "syment: %zu\n"
diff --git a/src/moduler/elf.h b/src/moduler/elf.h
index 34e5b72..cdb8abc 100644
--- a/src/moduler/elf.h
+++ b/src/moduler/elf.h
@@ -1,10 +1,12 @@
 #ifndef ELF_H_
 #define ELF_H_
 
+// TODO: Move these into .c file after API has found its form
+#include <elf.h>
 #include <libelf.h>
 #include <gelf.h>
 
-void *hi_elf_load_module(const char* filename);
+void *hi_elf_load_module(void *address, size_t n);
 void hi_elf_print_module_from_memory(void *address, size_t size);
 
 const char *dyn_type_to_str(unsigned type);
diff --git a/src/moduler/moduler.c b/src/moduler/moduler.c
index 9a12008..ca944f6 100644
--- a/src/moduler/moduler.c
+++ b/src/moduler/moduler.c
@@ -1,21 +1,64 @@
 #include "moduler.h"
 
+#include "common.h"
 #include "logger/logger.h"
 #include "memory.h"
 #include "moduler/elf.h"
+#include "string/string.h"
 #include "types.h"
 
+#include <dlfcn.h>
+#include <libelf.h>
+#include <link.h>
+#include <stdbool.h>
 #include <sys/mman.h>
 
+static HiloadResult moduler_apply_patch(void *address, size_t n) {
+
+  HiloadResult ret = HILOAD_FAIL;
+
+  Elf *elf = elf_memory(address, n);
+
+  hi_elf_print_module_from_memory(address, n);
+  ret = HILOAD_OK;
+
+  elf_end(elf);
+
+  return ret;
+}
+
 HiloadResult moduler_reload(HiModuleData *module,
-                            const struct sc_array_memreg *const memregs) {
+                            struct sc_array_memreg *memregs) {
 
   MemoryRegionSpan memspan = memory_get_module_span(memregs, module->name);
   log_debugv("Module: %s - [%p, %p]\n", module->name, memspan.region_start,
              memspan.region_end);
 
-  void *address = hi_elf_load_module(module->name);
-  log_debug("modaddress: %p\n", address);
+  dlerror();
+  char patch_name[512];
+  size_t written =
+      hi_strncat_buf(sizeof(patch_name), patch_name, module->name, ".patch");
+  if (!written) {
+    log_error("Failed to concat %s and %s\n", module->name, ".patch");
+    return HILOAD_FAIL;
+  }
+
+  log_debug("Opening: %s\n", patch_name);
+
+  void *new_handle = dlopen(patch_name, RTLD_NOW);
+  if (!new_handle) {
+    log_error("Couldn't load: %s\n", dlerror());
+    module->state = HI_MODULE_STATE_CLEAN;
+    return HILOAD_FAIL;
+  }
+
+  read_memory_maps_self(memregs);
+  memspan = memory_get_module_span(memregs, patch_name);
+
+  void *patch_address = (void *)memspan.region_start;
+  log_debug("patch address: %p\n", patch_address);
+
+  moduler_apply_patch(patch_address, memspan.region_end - memspan.region_start);
 
   module->state = HI_MODULE_STATE_CLEAN;
   return HILOAD_OK;
diff --git a/src/moduler/moduler.h b/src/moduler/moduler.h
index 4a71ccd..efe39f7 100644
--- a/src/moduler/moduler.h
+++ b/src/moduler/moduler.h
@@ -24,7 +24,6 @@ sc_array_def(HiModuleData, module);
 typedef struct sc_array_module HiModuleArray;
 
 HiloadResult moduler_reload(HiModuleData *module,
-                            const struct sc_array_memreg *const memregs);
-
+                            struct sc_array_memreg *memregs);
 
 #endif // MODULER_H_
diff --git a/src/string/string.c b/src/string/string.c
index b5b82c1..7021529 100644
--- a/src/string/string.c
+++ b/src/string/string.c
@@ -1,10 +1,33 @@
 #include "string.h"
 
+#include "common.h"
+
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
+size_t hi_strncat_buf(size_t buflen, char buf[buflen], const char *first, const char *second) {
+  if (!buf) return 0;
+
+  size_t first_len = strlen(first);
+  size_t second_len = strlen(second);
+
+  if (buf + first_len + second_len > buf + buflen - 1) {
+    return 0;
+  }
+
+  char * first_end = buf + first_len;
+  char * second_end = first_end + second_len;
+
+  strncpy(buf, first, first_end - buf);
+  strncpy(first_end, second, second_end - first_end);
+
+  *second_end = '\0';
+
+  return second_end - buf;
+}
+
 int hi_path_has_filename(const char *path, const char *filename) {
 
   const char *compared_filename = path;
diff --git a/src/string/string.h b/src/string/string.h
index f15a6b3..9ebd43e 100644
--- a/src/string/string.h
+++ b/src/string/string.h
@@ -3,6 +3,18 @@
 
 #include <stddef.h>
 
+/**
+ * Concatenate two strings into a buffer.
+ *
+ * If resulting string would be longer than buflen - 1, the resulting string in \p
+ * buf is unchanged.
+ *
+ * @param first Null terminated character string
+ * @param second Null terminated character string
+ */
+size_t hi_strncat_buf(size_t bufsize, char buf[bufsize], const char *first,
+                      const char *second);
+
 /**
  * @brief Copy file content to a null terminated string, allocating memory while
  * reading.
@@ -18,8 +30,7 @@
  * @param nmax if not 0, this amount of memory in bytes is read and used as
  * initial allocation
  */
-char *hi_string_from_file_dyn(const char *filename, size_t *nread,
-                                    size_t nmax);
+char *hi_string_from_file_dyn(const char *filename, size_t *nread, size_t nmax);
 
 /**
  * Find if filename exists at the end of path.