From d0a849ffeb541a8c285a92558cedcd6611072540 Mon Sep 17 00:00:00 2001
From: Jonas Hvid <mail@johv.dk>
Date: Sun, 4 Oct 2020 01:25:48 +0200
Subject: [PATCH] Supply UEFI module path as environment variable

We'd like to have multiple backends -- e.g. Linux instead of UEFI. That would
make testing less cumbersome.

Also remove an outdated comment.
---
 Makefile                |  4 ++--
 main.asm                | 16 +---------------
 uefi.asm => os/uefi.asm |  0
 3 files changed, 3 insertions(+), 17 deletions(-)
 rename uefi.asm => os/uefi.asm (100%)

diff --git a/Makefile b/Makefile
index ff474b0..362c429 100644
--- a/Makefile
+++ b/Makefile
@@ -14,9 +14,9 @@ OVMF_CODE.fd: /usr/share/ovmf/x64/OVMF_CODE.fd
 OVMF_VARS.fd: /usr/share/ovmf/x64/OVMF_VARS.fd
 	cp $< $@
 
-out/main: main.asm impl.asm bootstrap.asm sys.f uefi.asm
+out/main: main.asm impl.asm bootstrap.asm sys.f os/uefi.asm
 	mkdir -p out
-	fasm $< out/main
+	OS_INCLUDE=os/uefi.asm fasm $< $@
 
 .PHONY: clean
 clean:
diff --git a/main.asm b/main.asm
index 43eef7a..0190d18 100644
--- a/main.asm
+++ b/main.asm
@@ -1,18 +1,6 @@
 ;; vim: syntax=fasm
 
-include "uefi.asm"
-
-;; "Syscalls" {{{
-
-;; [NOTE] Volatile registers Linux (syscalls) vs UEFI
-;;
-;;   Linux syscalls: RAX, RCX, R11
-;;   UEFI:           RAX, RCX, R11, RDX, R8, R9, R10
-
-;; We are in the process of replacing our dependency on Linux with a dependency
-;; on UEFI. The following macros attempt to isolate what would be syscalls in
-;; Linux; thus, we will be able to replace these with UEFI-based implementations,
-;; and in theory we should expect the program to work.
+include '%OS_INCLUDE%'
 
 ;; Print a string of a given length.
 ;;
@@ -64,8 +52,6 @@ macro sys_terminate code {
   call uefi_terminate
 }
 
-;; }}}
-
 ;; The code in this macro is placed at the end of each Forth word. When we are
 ;; executing a definition, this code is what causes execution to resume at the
 ;; next word in that definition.
diff --git a/uefi.asm b/os/uefi.asm
similarity index 100%
rename from uefi.asm
rename to os/uefi.asm
-- 
2.39.2