From 1c8d4e69205fd875f6bec3fa3bd929c2e7f52f62 Mon Sep 17 00:00:00 2001
From: Nicholas Noll <nbnoll@eml.cc>
Date: Sat, 20 Nov 2021 09:53:11 -0800
Subject: Feature: self hosting prototype implemented

This is a large change. In order to remove myself from libc's arcane
interface, I implemented an independent runtime layer. It is based on
musl's wonderful implementation mostly. Critically, if libc is linked to
the program, then we cooperate. Namely, we call start main and let libc
do all initialization. If not, then we have a noop defined in rt3.a.

The general structure of the file is:
1. sys/$os/$arch contains all architecture dependent code
2. sys/$os/port contains all code that depends on the os, but is
   portable
3. rt/$arch contains all the runtime architecture dependent code
4. rt/* contains the portable runtime code.

Obviously testing is needed. Specifically, while code is checked in for
the most popular architectures, it only has been tested on one computer!
Overall this is exciting and as been educational.
---
 rules.mk | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

(limited to 'rules.mk')

diff --git a/rules.mk b/rules.mk
index e03a1c4..8c7bb2c 100644
--- a/rules.mk
+++ b/rules.mk
@@ -1,5 +1,5 @@
 # Standard housekeeping
-.PHONY: 	all debug release clean target install
+.PHONY: 	all debug release system bins libs tests clean target install
 .SUFFIXES:
 
 all: targets
@@ -27,10 +27,6 @@ TEST :=
 
 GENS :=
 
-# iterate through source directory tree
-DIR := src
-include $(DIR)/rules.mk
-
 # generic rules
 %.a: %.o
 	$(ARCHIVE)
@@ -39,9 +35,10 @@ include $(DIR)/rules.mk
 	$(LINK)
 
 # explicit system layer
-include sys.mk
+DIR := sys
+include $(DIR)/rules.mk
 
-# rules for userland
+# userland rules
 $(OBJ_DIR)/%.o: $(SRC_DIR)/%.c
 	$(COMPILE)
 
@@ -51,11 +48,18 @@ $(OBJ_DIR)/%.o: $(SRC_DIR)/%.s
 $(OBJ_DIR)/%: $(SRC_DIR)/%.c
 	$(COMPLINK)
 
-targets: $(SYS) $(LIBS) $(BINS) $(TEST)
+# iterate through source directory tree
+DIR := src
+include $(DIR)/rules.mk
+
+system: $(RUNTIME)
+bins:  system $(BINS)
+tests: system $(TEST)
+targets: libs bins tests
 
 clean:
 	@echo removing system layer
-	@rm -f $(SYS_OBJS) $(OBJ_DIR)/sys/sys.a
+	@rm -f $(SYS_OBJS) $(SYS) $(RT) $(RT_OBJS) $(RT1) $(RTI) $(RTN)
 	@echo removing object files
 	@rm -f $(OBJS)
 	@echo removing dependency files
-- 
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