add sample hello world assembly exec

.gitignore

@@ -0,0 +1,2 @@
+hello
+*.obj

Makefile

@@ -0,0 +1,15 @@
+.PHONY: compile link info exec
+
+dyn: compile link exec
+
+compile:
+	as hello.s -o hello.obj
+link:
+	@#ld -m elf_x86_64 --entry=main -lc --dynamic-linker /lib64/ld-linux-x86-64.so.2 -o hello hello.obj
+	ld -m elf_x86_64 -o hello hello.obj
+
+exec:
+	@./hello
+
+info:
+	readelf -a hello

hello.s

@@ -0,0 +1,22 @@
+.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
+
+    movl    $len,%edx           # third argument: message length
+    movl    $msg,%ecx           # second argument: pointer to message to write
+    movl    $1,%ebx             # first argument: file handle (stdout)
+    movl    $4,%eax             # system call number (sys_write)
+    int     $0x80               # call kernel
+				# and exit
+
+    movl    $0,%ebx             # first argument: exit code
+    movl    $1,%eax             # system call number (sys_exit)
+    int     $0x80               # call kernel
+
+.data                           # section declaration
+											msg:
+    .ascii    "Hello, world!\n"   # our dear string
+    len = . - msg                 # length of our dear string