diff --git a/tools/Makefile b/tools/Makefile
index 5930ac9f..2521141a 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -1,4 +1,4 @@
-all: elf2nso build_pfs0
+all: elf2nso elf2nro build_pfs0
 
 build_pfs0: build_pfs0.c
 	gcc $(CFLAGS) -o $@ $^
@@ -6,9 +6,12 @@ build_pfs0: build_pfs0.c
 elf2nso: elf2nso.c sha256.c
 	gcc $(CFLAGS) -o $@ $^ -llz4
 
+elf2nro: elf2nro.c
+	gcc $(CFLAGS) -o $@ $^
+
 install: all
 	cp build_pfs0 $(DEVKITA64)/bin/
 	cp elf2nso $(DEVKITA64)/bin/
 
 clean:
-	rm -f elf2nso build_pfs0
+	rm -f elf2nso elf2nro build_pfs0
diff --git a/tools/elf2nro.c b/tools/elf2nro.c
new file mode 100644
index 00000000..b7feb488
--- /dev/null
+++ b/tools/elf2nro.c
@@ -0,0 +1,170 @@
+// Copyright 2017 plutoo
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <lz4.h>
+#include "sha256.h"
+#include "elf64.h"
+
+typedef uint64_t u64;
+typedef uint32_t u32;
+typedef uint8_t u8;
+
+typedef struct {
+    u32 FileOff;
+    u32 Size;
+} NsoSegment;
+
+typedef struct {
+    u32 unused;
+    u32 modOffset;
+    u8 Padding[8];
+} NroStart;
+
+typedef struct {
+    u8  Magic[4];
+    u32 Unk1;
+    u32 size;
+    u32 Unk2;
+    NsoSegment Segments[3];
+    u32 bssSize;
+    u32 Unk3;
+    u8  BuildId[0x20];
+    u8  Padding[0x20];
+} NroHeader;
+
+uint8_t* ReadEntireFile(const char* fn, size_t* len_out) {
+    FILE* fd = fopen(fn, "rb");
+    if (fd == NULL)
+        return NULL;
+
+    fseek(fd, 0, SEEK_END);
+    size_t len = ftell(fd);
+    fseek(fd, 0, SEEK_SET);
+
+    uint8_t* buf = malloc(len);
+    if (buf == NULL) {
+        fclose(fd);
+        return NULL;
+    }
+
+    size_t rc = fread(buf, 1, len, fd);
+    if (rc != len) {
+        fclose(fd);
+        free(buf);
+        return NULL;
+    }
+
+    *len_out = len;
+    return buf;
+}
+
+int main(int argc, char* argv[]) {
+    if (argc != 3) {
+        fprintf(stderr, "%s <elf-file> <nro-file>\n", argv[0]);
+        return EXIT_FAILURE;
+    }
+    
+    NroStart nro_start;
+    memset(&nro_start, 0, sizeof(nro_start));
+
+    NroHeader nro_hdr;
+    memset(&nro_hdr, 0, sizeof(nro_hdr));
+    memcpy(nro_hdr.Magic, "NRO0", 4);
+
+    if (sizeof(NroHeader) != 0x70) {
+        fprintf(stderr, "Bad compile environment!\n");
+        return EXIT_FAILURE;
+    }
+
+    size_t elf_len;
+    uint8_t* elf = ReadEntireFile(argv[1], &elf_len);
+    if (elf == NULL) {
+        fprintf(stderr, "Failed to open input!\n");
+        return EXIT_FAILURE;
+    }
+
+    if (elf_len < sizeof(Elf64_Ehdr)) {
+        fprintf(stderr, "Input file doesn't fit ELF header!\n");
+        return EXIT_FAILURE;
+    }
+
+    Elf64_Ehdr* hdr = (Elf64_Ehdr*) elf;
+    if (hdr->e_machine != EM_AARCH64) {
+        fprintf(stderr, "Invalid ELF: expected AArch64!\n");
+        return EXIT_FAILURE;
+    }
+
+    Elf64_Off ph_end = hdr->e_phoff + hdr->e_phnum * sizeof(Elf64_Phdr);
+
+    if (ph_end < hdr->e_phoff || ph_end > elf_len) {
+        fprintf(stderr, "Invalid ELF: phdrs outside file!\n");
+        return EXIT_FAILURE;
+    }
+
+    Elf64_Phdr* phdrs = (Elf64_Phdr*) &elf[hdr->e_phoff];
+    size_t i, j = 0;
+    size_t file_off = sizeof(NroHeader) + sizeof(NroStart);
+
+    uint8_t* comp_buf[3];
+    int comp_sz[3];
+
+    for (i=0; i<4; i++) {
+        Elf64_Phdr* phdr = NULL;
+        while (j < hdr->e_phnum) {
+            Elf64_Phdr* cur = &phdrs[j++];
+            if (cur->p_type == PT_LOAD || i == 3) {
+                phdr = cur;
+                break;
+            }
+        }
+
+        if (phdr == NULL) {
+            fprintf(stderr, "Invalid ELF: expected 3 loadable phdrs and a bss!\n");
+            return EXIT_FAILURE;
+        }
+        
+        // .bss is special
+        if (i == 3) {
+            nro_hdr.bssSize = (phdr->p_memsz + 0xFFF) & ~0xFFF;
+            break;
+        }
+
+        nro_hdr.Segments[i].FileOff = file_off;
+        nro_hdr.Segments[i].Size = phdr->p_filesz + phdr->p_memsz;
+        nro_hdr.Segments[i].Size = (nro_hdr.Segments[i].Size + 0xFFF) & ~0xFFF;
+        comp_buf[i] = malloc(phdr->p_filesz);
+
+        if (comp_buf[i] == NULL) {
+            fprintf(stderr, "Out of memory!\n");
+            return EXIT_FAILURE;
+        }
+        
+        memcpy(comp_buf[i], &elf[phdr->p_offset], phdr->p_filesz);
+
+        file_off += phdr->p_filesz + phdr->p_memsz;
+        file_off = (file_off + 0xFFF) & ~0xFFF;
+    }
+
+    FILE* out = fopen(argv[2], "wb");
+
+    if (out == NULL) {
+        fprintf(stderr, "Failed to open output file!\n");
+        return EXIT_FAILURE;
+    }
+    
+    nro_hdr.size = file_off;
+
+    // TODO check retvals
+    fwrite(&nro_start, sizeof(nro_start), 1, out);
+    fwrite(&nro_hdr, sizeof(nro_hdr), 1, out);
+
+    for (i=0; i<3; i++)
+    {
+        fseek(out, nro_hdr.Segments[i].FileOff, SEEK_SET);
+        fwrite(comp_buf[i], comp_sz[i], 1, out);
+    }
+
+    return EXIT_SUCCESS;
+}