SparrowOSTS_121127.ISO

SparrowOS/Demo/Asm/AsmHelloWorld.CPP

@@ -0,0 +1,52 @@
+/*
+This is a JIT file, not static.
+
+Asm labels can only be defined once
+in a task.  Hit F5 to spawn a new task
+and run it.
+
+These are many useful kernel
+routines $LK,"::/SparrowOS/OSMain/Str1a.CPP.Z","FF:::/SparrowOS/OSMain/Str1a.CPP.Z,PUT_CHAR"$
+intended to be called from
+asm.  Generally, they preserve
+regs.
+
+You can call any routine you
+like, C or asm, if you import it.
+Be aware that C routines do not
+preserve RAX,RBX,RCX,RDX,R8,R9.
+When calling from the shell or
+from C, preserve all other regs.
+
+*/
+
+asm {
+//Opcodes are slightly different to make writing my x86_64 assembler easier.
+//See $LK,"::/SparrowOS/Compiler/OpCodes.TXT.Z","FI:::/SparrowOS/Compiler/OpCodes.TXT.Z"$.
+
+USE64	//Defaults to 64, but this is a good habit.
+
+	IMPORT	PUT_HEX_U8,PUT_CHAR;
+
+MY_MSG:
+//Define U8 does not put terminating zeros
+//on strings.
+	DU8	"Hello World\n",0;
+
+//My convention is to put an underscore
+//on C callable routines.
+_HELLO_WORLD::
+	MOV	RCX,10
+@@05:	MOV	RAX,RCX
+	CALL	PUT_HEX_U8
+	MOV	RAX,CH_SPACE
+	CALL	PUT_CHAR
+	MOV	RSI,MY_MSG
+//Alternatively, if you use an '&', you don't need
+//to import a SYS_SYM.  This only works for JIT asm.
+	CALL	&PUT_STR
+	LOOP	@@05
+	RET
+};
+
+Call(_HELLO_WORLD);