Added header module for self-contained linux programs

git-svn-id: https://svn.inf.ethz.ch/svn/lecturers/a2/trunk@6501 8c9fc860-2736-0410-a75d-ab315db34111

source/FoxAMD64Assembler.Mod

@@ -1132,6 +1132,7 @@ TYPE
 			pass: LONGINT;
 			absoluteMode: BOOLEAN;
 			absoluteOffset: LONGINT;
+			alignment: LONGINT;
 			orgOffset: LONGINT;
 			char: CHAR;
 			orgReaderPos: LONGINT;
@@ -1439,6 +1440,17 @@ TYPE
 				RETURN TRUE;
 			END Expression;
 
+			PROCEDURE Align(size: LONGINT);
+			VAR pc: LONGINT;
+			BEGIN
+				IF size <= 0 THEN Error("invalid alignment size"); RETURN END;
+				pc := emitter.code.pc DIV 8; (* bytes *)
+				WHILE pc MOD size # 0 DO
+					emitter.code.PutByte(0); 
+					INC(pc);
+				END;
+			END Align;
+			
 
 			PROCEDURE PutData (size: Size): BOOLEAN;
 			VAR i: LONGINT; type:SHORTINT; ofs: Operand;
@@ -2036,6 +2048,11 @@ TYPE
 							ELSE
 								NextSymbol;
 							END;
+						ELSIF ident = "ALIGN" THEN
+							NextSymbol;
+							IF Expression(alignment, TRUE, type) THEN
+								Align(alignment);
+							END;
 						ELSIF ~(scope # NIL) & (ident = "CPU") THEN
 							IF ~GetCPU (FALSE) THEN
 								SkipLine;

source/Linux.I386.ElfHeader.Mod

@@ -0,0 +1,172 @@
+(* Minimal ELF header for self contained linux Oberon programs *)
+(* Copyright (c) Felix Friedrich, ETH Zürich *)
+(* Extracted in parts from Florian Negele's Eigen Compiler Suite *)
+
+MODULE ElfHeader; 
+
+IMPORT SYSTEM, Trace;
+
+VAR
+	empty-: RECORD END; (* empty variable linked to end of kernel *)
+
+	dlsym-	: PROCEDURE {C} ( handle: ADDRESS; name: ADDRESS): ADDRESS;
+	dlopen-	: PROCEDURE {C} ( pathname: ADDRESS; mode: LONGINT ): ADDRESS;
+	dlclose-	: PROCEDURE {C} ( handle: ADDRESS );
+
+	PROCEDURE {INITIAL, NOPAF} EntryPoint;
+	CONST base = 08048000H;
+	CODE
+		; ELF header
+		DB 07FH, 'ELF', 1, 1, 1, 0
+		DD 0, 0
+		DW 02, 03
+		DD 01
+		DD entry + base; program entry point
+		DD elfheadersize
+		DD 0
+		DD 0
+		DW elfheadersize
+		DW 20H
+		DW 3 ; #program header table entries
+		DW 0
+		DW 0
+		DW 0
+
+		elfheadersize:
+
+		; program header
+		DD 1
+		DD 0
+		DD base; 
+		DD base; 
+		DD @empty - base; segment size (file)
+		DD @empty - base; segment size (memory)
+		DD 07
+		DD 1000H; alignment
+		
+		; interpreter header
+		DD 3
+		DD interpretername; interpreter name offset
+		DD interpretername + base; interpreter name 
+		DD interpretername + base; interpreter name
+		DD 13H ; interpreter name length
+		DD 13H ; interpreter name length
+		DD 4H
+		DD 1H
+
+		; dynamic header
+		DD 02H
+		DD dynamicsection 
+		DD dynamicsection + base
+		DD dynamicsection + base
+		DD 40H ; size of dynamic section
+		DD 40H ; size of dynamic section
+		DD 06H
+		DD 04H
+
+		dynamicsection:
+		DD 05H, base + stringtable
+		DD 06H, symboltablebegin + base
+		DD 07H, dlsymrelocation + base
+		DD 08H, stringtable-dlsymrelocation ; size (relocationtable)
+		DD 09H, 0CH
+		DD 0AH, endstringtable - stringtable; size (stringtable)
+		DD 0BH, 10H
+		
+		DD 01H, libname - stringtable; position of libname
+		DD 0H, 0H ; sentinel
+
+	 	dlsymrelocation:
+		DD @dlsym
+		DB 01H
+		DB 01H, 00H, 00H; index of the symbol
+		DD 0H
+
+		stringtable:
+		DB 0H ; sentinel
+
+		libname:
+		DB 'libdl.so.2', 0
+		
+		dlsymname:
+		DB 'dlsym', 0
+		
+		endstringtable:
+		
+		ALIGN 4
+		symboltablebegin:
+		DD	0;
+		DD	0
+		DD	0
+		DB	0
+		DB	0
+		DW 0
+		
+		; dlsym symbol
+		DD dlsymname - stringtable; position of dlsymname
+		DD	0
+		DD	0
+		DB	12H
+		DB 0
+		DW	0
+
+		interpretername:
+		DB '/lib/ld-linux.so.2', 0
+
+		ALIGN 4
+
+		entry:
+	END EntryPoint;
+
+
+	PROCEDURE {NOPAF} putc*(file: ADDRESS; c: CHAR);
+	CODE
+		PUSH ECX
+		MOV EAX, 4
+		MOV EBX, [ESP + 12]
+		LEA ECX, [ESP+8]	
+		MOV EDX, 1
+		INT 80H
+		POP ECX
+		JNE fail
+		MOV EAX, [ESP + 4]
+		RET
+		fail:
+		MOV EAX, -1
+		RET
+	END putc;
+
+	PROCEDURE Dlsym*(handle: ADDRESS; CONST name: ARRAY OF CHAR; adr: ADDRESS);
+	VAR val: ADDRESS;
+	BEGIN
+		val := dlsym(handle, ADDRESS OF name[0]);
+		SYSTEM.PUT32(adr, val);
+	END Dlsym;
+
+	PROCEDURE Char(c: CHAR);
+	BEGIN
+		putc(1, c);
+	END Char;
+ 
+	PROCEDURE Init;
+	BEGIN
+		Trace.Char := Char;
+		Dlsym(0,"dlopen", ADDRESS OF dlopen);
+		ASSERT(dlopen # NIL); 
+		Dlsym( 0, "dlclose", ADDRESS OF dlclose);
+		ASSERT(dlclose # NIL); 
+	END Init;
+
+BEGIN
+	Init;
+	Trace.String("ElfHeader loaded");
+END ElfHeader.
+
+SystemTools.DoCommands
+	Compiler.Compile -b=AMD --objectFile=Generic --symbolFile=Textual --objectFileExtension=.GofU --symbolFileExtension=.SymU
+		Runtime.Mod Trace.Mod Linux.I386.ElfHeader.Mod  ~ 
+
+	StaticLinker.Link --fileFormat=Raw --fileName=simple_elf --extension=.GofU --displacement=08048000H
+		Runtime Trace ElfHeader
+		~ 
+