From a03745805b007758a07368fea777bca629942516 Mon Sep 17 00:00:00 2001
From: Nathan Cannon <neviynhd@gmail.com>
Date: Tue, 7 Nov 2017 01:39:24 +0000
Subject: [PATCH] Remove C usage

---
 kernel/arch/i386/tty.nim | 14 +++++++-------
 kernel/panicoverride.nim | 10 ++--------
 nim.cfg                  |  4 ++--
 3 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/kernel/arch/i386/tty.nim b/kernel/arch/i386/tty.nim
index 09836f8..c7d3baf 100644
--- a/kernel/arch/i386/tty.nim
+++ b/kernel/arch/i386/tty.nim
@@ -20,8 +20,8 @@ proc terminalWriteAtPoint(writeChar: char, colour: int, xPos: int, yPos: int) =
   vgaMem[index] = vga.vgaEntry(writeChar, terminalColour)
 
 proc terminalClear*() =
-  for x in 0..<vgaWidth:
-    for y in 0..<vgaHeight:
+  for x in 0 .. vgaWidth - 1:
+    for y in 0 .. vgaHeight - 1:
       terminalWriteAtPoint(' ', terminalColour, x, y)
   terminalRow = 0
   terminalColumn = 0
@@ -31,12 +31,12 @@ proc terminalInitialize*() =
   terminalClear()
 
 proc terminalScroll() =
-  for y in 0..< (vgaHeight - 1):
+  for y in 0 .. (vgaHeight - 2):
     let base1 = y * vgaWidth
     let base2 = (y + 1) * vgaWidth
-    for x in 0..<vgaWidth:
+    for x in 0 .. vgaWidth - 1:
       vgaMem[base1 + x] = vgaMem[base2 + x]
-  for x in 0..<vgaWidth: # Blank the "new" bottom line
+  for x in 0 .. vgaWidth - 1: # Blank the "new" bottom line
     terminalWriteAtPoint(' ', terminalColour, x, vgaHeight - 1)
 
 proc setTerminalColour(newColour: int) =
@@ -59,8 +59,8 @@ proc terminalWriteChar(writeChar: char) =
     scrollCheckAndSet()
 
 proc terminalWrite*(data: string) =
-  for character in data:
-    terminalWriteChar(character)
+  for i in 0 .. data.len - 1:
+    terminalWriteChar(data[i])
 
 proc terminalWrite*(data: char) =
   terminalWriteChar(data)
diff --git a/kernel/panicoverride.nim b/kernel/panicoverride.nim
index b39f0c3..235eecf 100644
--- a/kernel/panicoverride.nim
+++ b/kernel/panicoverride.nim
@@ -1,17 +1,12 @@
-
-{.push debugger:off, hints:off.}
-
-proc printf(frmt: cstring) {.varargs, importc, header: "<stdio.h>", cdecl.}
-proc exit(code: int) {.importc, header: "<stdlib.h>", cdecl.}
+import tty
 
 {.push stack_trace: off, profiler:off.}
 
 proc rawoutput(s: string) =
-  printf("%s\n", s)
+  tty.terminalWrite(s)
 
 proc panic(s: string) =
   rawoutput(s)
-  exit(1)
 
 # Alternatively we also could implement these 2 here:
 #
@@ -19,4 +14,3 @@ proc panic(s: string) =
 # template sysFatal(exceptn: typeDesc, message, arg: string)
 
 {.pop.}
-{.pop.}
\ No newline at end of file
diff --git a/nim.cfg b/nim.cfg
index bfe0008..a075888 100644
--- a/nim.cfg
+++ b/nim.cfg
@@ -5,6 +5,6 @@
 --path:"kernel/arch/i386"
 --cpu:i386
 --os:standalone
---passC:"-ffreestanding -nostdlib --target=i386-pc-none-elf -march=i386 -lc"
---passL:"-ffreestanding -target i386 -nostdlib -T ./kernel/arch/i386/linker.ld boot.o -lc"
+--passC:"-ffreestanding -nostdlib --target=i386-pc-none-elf -march=i386"
+--passL:"-ffreestanding -target i386 -nostdlib -T ./kernel/arch/i386/linker.ld boot.o"
 --out:"myos.bin"