Initial Spring 2016 commit.

mk/os161.config-mips.mk

@@ -0,0 +1,32 @@
+#
+# OS/161 build environment extra definitions for MIPS.
+# This is included by os161.config.mk.
+#
+
+
+#
+# The MIPS toolchain for OS/161 is an ELF toolchain that by default
+# generates SVR4 ELF ABI complaint code. This means that by default
+# all code is PIC (position-independent code), which is all very well
+# but not something we need or want in the kernel. So we use -fno-pic
+# to turn this behavior off.
+#
+# We turn it off for userland too because we don't support shared
+# libraries. Before trying to implement shared libraries, these
+# options need to be taken out of CFLAGS.
+#
+# It turns out you also need -mno-abicalls to turn it off completely.
+#
+
+CFLAGS+=-mno-abicalls -fno-pic
+KCFLAGS+=-mno-abicalls -fno-pic
+
+#
+# Extra stuff required for the kernel.
+#
+# -ffixed-23 reserves register 23 (s7) to hold curthread. This register
+# number must match the curthread definition in mips/thread.h and the
+# code in trap.S.
+#
+KCFLAGS+=-ffixed-23
+KLDFLAGS+=