Initial checkin of toy OS project.HEADmaster

3 files changed, 110 insertions, 0 deletions

diff --git a/kernel/init/Makefile b/kernel/init/Makefile
new file mode 100644
index 0000000..815dc69
--- /dev/null
+++ b/kernel/init/Makefile
@@ -0,0 +1,20 @@
+CC=			gcc
+CFLAGS= 		-Wall -imacros ../defines -I../inc
+OBJS=			main.o entry.o
+RM=			/bin/rm
+NASM=			nasm
+NASMFLAGS=		-f elf
+
+.SUFFIXES: .c .asm .o
+
+all: $(OBJS)
+
+.c.o:
+	$(CC) $(CFLAGS) -c $<
+
+.asm.o:
+	$(NASM) $(NASMFLAGS) -o $*.o $<
+
+clean:
+	$(RM) -f $(OBJS) *~ #*# .#*
+
diff --git a/kernel/init/entry.asm b/kernel/init/entry.asm
new file mode 100644
index 0000000..afb0434
--- /dev/null
+++ b/kernel/init/entry.asm
@@ -0,0 +1,23 @@
+[BITS 32]
+
+EXTERN KernelEntry
+GLOBAL StartOfKernelImage
+GLOBAL IdleLoop
+                
+;;; 
+;;; I put "entry.o" first in line at the linker so I am sure this function
+;;; gets put first in the kernel image.  This is good because:
+;;;
+;;;     1. We know there is valid code at 0x00010000 when we jump here
+;;;     2. We can use the address of this function as the start of image
+;;;     3. We don't have to make sure main (or KernelEntry or whatever) 
+;;;        is always the first function in main.c
+;;; 
+StartOfKernelImage:
+        jmp KernelEntry
+        ret
+
+IdleLoop:
+        sti
+        hlt
+        jmp IdleLoop
diff --git a/kernel/init/main.c b/kernel/init/main.c
new file mode 100644
index 0000000..22fd14a
--- /dev/null
+++ b/kernel/init/main.c
@@ -0,0 +1,67 @@
+//+----------------------------------------------------------------------------
+//
+// File:     main.c
+//
+// Module:   
+//
+// Synopsis: 
+//
+// Created:  sgasch  4 Jul 2003
+//
+//+----------------------------------------------------------------------------
+
+#include "kernel.h"
+#include "hal.h"
+#include "rtl.h"
+
+extern char __bss_start;
+extern char end;
+
+void
+ZeroBSS(void)
+{
+    BYTE *pBssStart, *pBssEnd;
+
+    pBssStart = &__bss_start;
+    pBssEnd = &end;
+
+    // Fill .bss section with zero
+    RtlSetMemory((void *)pBssStart, '\0', (pBssEnd - pBssStart));
+}
+
+void
+_assert(CHAR *szFunction, CHAR *szFile, ULONG uLine)
+{
+    HalVideoSetCursorPosition(0, 0);
+    HalVideoPrint("ASSERTION in %s at %s line %u.\n",
+               szFunction, szFile, uLine);
+    while(1)
+    {
+        ;
+    }
+}
+
+//
+// Entry point of the kernel.  Not called main because I don't care to 
+// listen to gcc's warnings about argc and argv anymore.
+//
+int
+KernelEntry(BIOS_HARDWARE_BLOCK *phw)
+{
+    ZeroBSS();
+
+    HalVideoInitialize(phw);
+    HalInitializeInterrupts();
+
+    HalVideoPrint("Interrupts initialized.\n");
+    
+ hang:
+    HalReadTimestampCounter();
+    HalVideoPrint("Timestamp Counter: %u%u\n", 
+                  ((g_ullTimeStampCounter >> 32) & 0xffffffff),
+                  (g_ullTimeStampCounter & 0xffffffff));
+    goto hang;
+
+    return(-1);
+}
+