Added processors module for Raspberry Pi

git-svn-id: https://svn.inf.ethz.ch/svn/lecturers/a2/trunk@6385 8c9fc860-2736-0410-a75d-ab315db34111

source/RPI.Processors.Mod

@@ -0,0 +1,80 @@
+(* Runtime support for Raspberry Pi *)
+(* Copyright (C) Florian Negele *)
+
+(** The Processors module represents all logical processors of the system. *)
+MODULE Processors;
+
+IMPORT SYSTEM, Counters, CPU;
+
+(** Indicates the maximal number of logical processors that are supported by the system. *)
+CONST Maximum* = 4 + CPU.Interrupts;
+
+(** Holds the actual number of processors in the system. *)
+VAR count- := 4: SIZE;
+
+VAR running: Counters.AlignedCounter; (* counts the number of application processors currently running *)
+
+(** Returns the unique index of the processor executing this procedure call. *)
+PROCEDURE GetCurrentIndex- EXTERN "Activities.GetCurrentProcessorIndex" (): SIZE;
+
+(** Suspends the execution of the current processor. *)
+(** A suspended processor must be resumed by a call to the Processors.ResumeAnyProcessor procedure. *)
+(** @topic Scheduling *)
+PROCEDURE SuspendCurrentProcessor-;
+CODE
+	WFE
+END SuspendCurrentProcessor;
+
+(** Resumes the execution of a single suspended processor. *)
+(** @topic Scheduling *)
+PROCEDURE ResumeAllProcessors-;
+CODE
+	SEV
+END ResumeAllProcessors;
+
+(** Starts the execution of all available processors. *)
+(** @topic Scheduling *)
+PROCEDURE StartAll-;
+CODE
+	SEV
+END StartAll;
+
+PROCEDURE {NORETURN} Boot;
+PROCEDURE Idle EXTERN "Activities.Idle";
+PROCEDURE Execute EXTERN "Activities.Execute" (procedure: PROCEDURE);
+BEGIN {UNCOOPERATIVE, UNCHECKED}
+	CODE
+		MOV	SP, #0x8000
+		MRC	P15, 0, R0, C0, C0, 5
+		AND	R0, R0, #0x3
+		SUB	SP, SP, R0, LSL #13
+	END;
+	CPU.EnableMemoryManagementUnit;
+	Counters.Inc (running);
+	SuspendCurrentProcessor;
+	SuspendCurrentProcessor;
+	Execute (Idle);
+	Counters.Dec (running);
+	CPU.Halt;
+END Boot;
+
+(** Initializes the module by enumerating all available processors. *)
+(** @topic Runtime Call *)
+PROCEDURE Initialize-;
+PROCEDURE Boot EXTERN "Processors.Boot";
+CONST Core1Mailbox = 04000009CH; Core2Mailbox = 0400000ACH; Core3Mailbox = 0400000BCH;
+BEGIN {UNCOOPERATIVE, UNCHECKED}
+	CPU.WriteWord (Core1Mailbox, ADDRESS OF Boot);
+	CPU.WriteWord (Core2Mailbox, ADDRESS OF Boot);
+	CPU.WriteWord (Core3Mailbox, ADDRESS OF Boot);
+	REPEAT UNTIL Counters.Read (running) = 3;
+END Initialize;
+
+(** Terminates the module and waits for all other processors to stop their execution. *)
+(** @topic Runtime Call *)
+PROCEDURE Terminate-;
+BEGIN {UNCOOPERATIVE, UNCHECKED}
+	REPEAT UNTIL Counters.Read (running) = 0;
+END Terminate;
+
+END Processors.