second commit

.vscode/settings.json

 {
     "files.associations": {
-        "task-descriptor.h": "c"
+        "task-descriptor.h": "c",
+        "bwio.h": "c"
     }
 }
\ No newline at end of file

include/kernel.h

@@ -11,6 +11,7 @@ typedef struct kernel {
     // a free list of pointers to free TDs. This might take the form of bits set in a couple of words. WHAT?
     // a structure for keeping the request currently being serviced, including its arguments.
     Request syscalReq;
+    TD* Active;
 } KernelStruct;
 
 

lib/syscall.c

@@ -2,8 +2,8 @@
 #include "syscall.h"
 
 int Create (int priority, void (*code)()) {
-    // assemble args into a Request
-    // then call syscallHandler
+    // assemble args into a Request struct
+    // then call syscallHandler and pass it that Request struct whih will invoke the appropriate kernel handler
     // return TaskID of new Task
 }
 

src/Makefile

@@ -19,56 +19,51 @@ ARFLAGS = rcs
 
 LDFLAGS = -init main -Map first.map -N -T orex.ld -L/u/wbcowan/gnuarm-4.0.2/lib/gcc/arm-elf/4.0.2 -L../lib
 
-all: startup.elf
+all: main.elf
 
-startup.s: startup.c
-	$(XCC) -S $(CFLAGS) startup.c
- 
-startup.o: startup.s
-	$(AS) $(ASFLAGS) -o startup.o startup.s
-
-startup.elf: startup.o
-	$(LD) $(LDFLAGS) -o $@ startup.o -lmycanvas -lmyclock -lcmd -lmyio -lbuffer -lbwio -lgcc
-
-clocktest.s: clocktest.c
-	$(XCC) -S $(CFLAGS) clocktest.c
+main.s: main.c
+	$(XCC) -S $(CFLAGS) main.c
 
-clocktest.o: clocktest.s
-	$(AS) $(ASFLAGS) -o clocktest.o clocktest.s
+main.o: main.s
+	$(AS) $(ASFLAGS) -o main.o main.s
 
-clocktest.elf: clocktest.o
-	$(LD) $(LDFLAGS) -o $@ clocktest.o -lbwio -lgcc
+main.elf: main.o
+	$(LD) $(LDFLAGS) -o $@ main.o -ltaskdescriptor -lscheduler -lbwio -lgcc
 
+scheduler.s: scheduler.c
+	$(XCC) -S $(CFLAGS) scheduler.c
 
-getc.s: getc.c
-	$(XCC) -S $(CFLAGS) getc.c
+taskdescriptor.s: taskdescriptor.c
+	$(XCC) -S $(CFLAGS) taskdescriptor.c
 
-getc.o: getc.s
-	$(AS) $(ASFLAGS) -o getc.o getc.s
-
-getc.elf: getc.o
-	$(LD) $(LDFLAGS) -o $@ getc.o -lbwio -lgcc
+bwio.s: bwio.c
+	$(XCC) -S $(CFLAGS) bwio.c
 
+ 
+scheduler.o: scheduler.s
+	$(AS) $(ASFLAGS) -o scheduler.o scheduler.s
 
-stop.s: stop.c
-	$(XCC) -S $(CFLAGS) stop.c
+taskdescriptor.o: taskdescriptor.s
+	$(AS) $(ASFLAGS) -o taskdescriptor.o taskdescriptor.s
 
-stop.o: stop.s
-	$(AS) $(ASFLAGS) -o stop.o stop.s
+bwio.o: bwio.s
+	$(AS) $(ASFLAGS) -o bwio.o bwio.s
 
-stop.elf: stop.o
-	$(LD) $(LDFLAGS) -o $@ stop.o -lbwio -lgcc
 
-tr.s: tr.c
-	$(XCC) -S $(CFLAGS) tr.c
+scheduler.a: scheduler.o
+	$(AR) $(ARFLAGS) $@ scheduler.o
 
-tr.o: tr.s
-	$(AS) $(ASFLAGS) -o tr.o tr.s
+taskdescriptor.a: taskdescriptor.o
+	$(AR) $(ARFLAGS) $@ taskdescriptor.o
 
-tr.elf: tr.o
-	$(LD) $(LDFLAGS) -o $@ tr.o -lmyio -lbuffer -lbwio -lgcc
+bwio.a: bwio.o
+	$(AR) $(ARFLAGS) $@ bwio.o
 
+install: bwio.a taskdescriptor.a scheduler.a
+	mv bwio.a ../../lib/libbwio.a
+	mv taskdescriptor.a ../../lib/libtaskdescriptor.a
+	mv scheduler.a ../../lib/libscheduler.a
 
 clean:
-	-rm -f *.elf *.s *.o startup.map *.a *~
+	-rm -f *.elf *.s *.o main.map *.a *~ ../../lib/*.a
 

src/context-switch.asm

 
 
 /* Entering Kernel */
+kernel-entry:
 //- save users lr in r3
 //- switch to system mode to find users SP
 //- push r4-r12 onto users stack
@@ -14,7 +15,7 @@
 
 /* exiting kernel */
 stmfd sp!, {r0, r4-r12, r14}
-CPSR[4:0] = 0b10011
+CPSR[4:0] = 0b10011 // supervisor
 // TODO ??
 movs pc, lr // jump outta kernel
 

src/main.c

-#include "kernel.h"
+// #include "kernel.h"
 #include "task-descriptor.h"
 #include "scheduler.h"
-#include "error.h"
+// #include "error.h"
 #include "bwio.h"
+#include "request.h"
 
 #define FOREVER while(1)
 
+void kerxit( TD *active, Request *req ) {
+    bwprintf( COM2, “kerxit.c: Hello.\n\r” );
+    bwprintf( COM2, “kerxit.c: Activating.\n\r” );
+    kerent( );
+    bwprintf( COM2, “kerxit.c: Good-bye.\n\r” );
+}
+
+void initialize()
+
+void handle(TD* Active, Request* req) {
+
+}
+
 int main(int argc, char const *argv[])
 {
-    KernelStruct Colonel;
-    TD* Active;
-    Request* syscallReq; 
-    int Status, TaskID;
-
-    // TODO turn off interrupts so it won't mess up RedBoot stuff
-    disableInterrupts();
+    // KernelStruct Colonel;
+    TD* Active; // TODO moved to kernel struct now
+    Request* req; 
+    // int Status, TaskID;
+    initialize( tds );
+    // tds is an array of TDs
+    for( i = 0; i < 4; i++ ) {
+        // active = schedule( tds );
+        kerxit( active, req );
+        // req is a pointer to a Request
+        handle( tds, req );
+    }
+    return 0;
+    // // TODO turn off interrupts so it won't mess up RedBoot stuff
+    // disableInterrupts();
 
-    kernelInit(&Colonel);
+    // kernelInit(&Colonel);
 
-    status = schedulerInit();
-    if (status) return FAILURE;
+    // status = schedulerInit();
+    // if (status) return FAILURE;
 
-    firstUserTaskChildren();
+    // firstUserTaskChildren();
     
-    return 0;
+    // return 0;
     // FOREVER {
     //     Active = getNextTaskScheduler(&Colonel);
 
     //     if (Active == NULL) break; // no tasks to run
         
-    //     syscallReq = activate(&Colonel, Active);
+    //     syscallReq = activate(&Colonel, Active); // restoring tasks registers
 
     //     handle(&Colonel, Active, syscallReq);
     // }
 
+    // declare kernel data structures
+
+
 }