From 2c2720323c844880e47d6f7313780be6230a9616 Mon Sep 17 00:00:00 2001
From: Ain <41307858+nero@users.noreply.github.com>
Date: Wed, 25 Sep 2019 20:45:50 +0000
Subject: [PATCH] WIP for config.sys parsing

---
 Makefile           |  2 +-
 kernel/config.asm  | 51 ++++++++++++++++++++++++++++++++++++++++++++++
 kernel/main.asm    |  3 +++
 kernel/rconfig.sys |  1 +
 4 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 kernel/config.asm
 create mode 100644 kernel/rconfig.sys

diff --git a/Makefile b/Makefile
index 708b11c..4f754bb 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 FLOPPY = 360
 
 PROGRAMS = $(patsubst %.asm,%.com,$(wildcard programs/*.asm))
-DISTFILES = rdos.sys $(PROGRAMS)
+DISTFILES = rdos.sys kernel/rconfig.sys $(PROGRAMS)
 ROMS =
 
 QEMU_ARCH = $(shell uname -m)
diff --git a/kernel/config.asm b/kernel/config.asm
new file mode 100644
index 0000000..5be6029
--- /dev/null
+++ b/kernel/config.asm
@@ -0,0 +1,51 @@
+config_tokens:
+.buffers:
+  db 8, "BUFFERS="
+.drives:
+  db 7, "DRIVES="
+.files:
+  db 6, "FILES="
+.none:
+  db 0
+
+; IN	SI	offset of needle
+;	DI	offset to haystack table
+; OUT	DI	found offset in table
+;	ZF	zero flag set if match
+config_search_token:
+  push bp
+  push cx
+.loop:
+  cmp BYTE [di], 0
+  je .fail
+  push si
+  push di
+  mov bp, di
+  xor ch, ch
+  mov cl, [di]
+  inc di
+  add bp, cx
+  inc bp
+  repe cmpsb
+  pop di
+  pop si
+  je .end
+  mov di, bp
+  jmp .loop
+.fail:
+  stc
+.end:
+  pop cx
+  pop cx
+  ret
+
+config_parse_int:
+  ret
+
+; IN	BX	offset to config data
+config_first_run:
+  mov si, bx
+  mov di, config_tokens
+  call config_search_token
+  int3
+  ret
diff --git a/kernel/main.asm b/kernel/main.asm
index e7d476c..873c448 100644
--- a/kernel/main.asm
+++ b/kernel/main.asm
@@ -38,6 +38,8 @@ init:
   mov ds, ax
   mov es, ax
 
+  call config_first_run
+
   mov di, kernel_end
   call drive_setup
 
@@ -56,5 +58,6 @@ init:
   hlt
   jmp .halt
 
+%include "config.asm"
 
 kernel_end:
diff --git a/kernel/rconfig.sys b/kernel/rconfig.sys
new file mode 100644
index 0000000..eab075f
--- /dev/null
+++ b/kernel/rconfig.sys
@@ -0,0 +1 @@
+DRIVES=4