Initialization

README.md

@@ -1,2 +1,24 @@
 # asm-trail
+
 A Simple Trail on Assembly.
+
+`nasm` could be Installed via `apt`.
+
+1. Compilation
+
+    ```sh
+    $ nasm ./init.asm -f elf64 -o ./init.o
+    ```
+
+2. Linking
+
+    ```sh
+    $ ld -s ./init.o -o ./init.out
+    ```
+
+3. Execution
+
+    ```sh
+    $ ./init.out
+    Holax, sekai!
+    ```

init.asm

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+section .data                           ;section declaration
+msg     db      "Holax, sekai!",0xA     ;our dear string
+len     equ     $ - msg                 ;length of our dear string
+section .text                           ;section declaration
+                       ;we must export the entry point to the ELF linker or
+   global _start       ;loader. They conventionally recognize _start as their
+                       ;entry point. Use ld -e foo to override the default.
+_start:
+;write our string to stdout
+       mov     eax,4   ;system call number (sys_write)
+       mov     ebx,1   ;first argument: file handle (stdout)
+       mov     ecx,msg ;second argument: pointer to message to write
+       mov     edx,len ;third argument: message length
+       int     0x80    ;call kernel
+;and exit
+       mov     eax,1   ;system call number (sys_exit)
+       xor     ebx,ebx ;first syscall argument: exit code
+       int     0x80    ;call kernel