Initial revision

kernel/sconst.h

@@ -0,0 +1,36 @@
+! Miscellaneous constants used in assembler code.
+W		=	_WORD_SIZE	! Machine word size.
+
+! Offsets in struct proc. They MUST match proc.h.
+P_STACKBASE	=	0
+#if _WORD_SIZE == 2
+ESREG		=	P_STACKBASE
+#else
+GSREG		=	P_STACKBASE
+FSREG		=	GSREG + 2	! 386 introduces FS and GS segments
+ESREG		=	FSREG + 2
+#endif
+DSREG		=	ESREG + 2
+DIREG		=	DSREG + 2
+SIREG		=	DIREG + W
+BPREG		=	SIREG + W
+STREG		=	BPREG + W	! hole for another SP
+BXREG		=	STREG + W
+DXREG		=	BXREG + W
+CXREG		=	DXREG + W
+AXREG		=	CXREG + W
+RETADR		=	AXREG + W	! return address for save() call
+PCREG		=	RETADR + W
+CSREG		=	PCREG + W
+PSWREG		=	CSREG + W
+SPREG		=	PSWREG + W
+SSREG		=	SPREG + W
+P_STACKTOP	=	SSREG + W
+P_LDT_SEL	=	P_STACKTOP
+P_LDT		=	P_LDT_SEL + W
+
+#if _WORD_SIZE == 2
+Msize		=	12		! size of a message in 16-bit words
+#else
+Msize		=	9		! size of a message in 32-bit words
+#endif