From 7ce2898b6ec2222f16991292a0e968fe0e60d2e7 Mon Sep 17 00:00:00 2001
From: "Justin C. Miller" <justin@devjustinian.com>
Date: Thu, 29 Mar 2018 09:49:38 -0700
Subject: [PATCH] Test for incoming data pointer in kernel_main

---
 src/modules/main/debug.s |  5 ++-
 src/modules/main/main.c  | 12 ++-----
 src/modules/main/vga.c   | 67 ----------------------------------------
 src/modules/main/vga.h   | 42 -------------------------
 4 files changed, 4 insertions(+), 122 deletions(-)
 delete mode 100644 src/modules/main/vga.c
 delete mode 100644 src/modules/main/vga.h

diff --git a/src/modules/main/debug.s b/src/modules/main/debug.s
index 14c43d4..187f6b7 100644
--- a/src/modules/main/debug.s
+++ b/src/modules/main/debug.s
@@ -3,9 +3,8 @@ section .text
 global do_the_set_registers
 do_the_set_registers:
 	mov rax, 0xdeadbeef0badc0de
-	mov rbx, 0xdeadbeef0badc0de
-	mov rcx, 0xdeadbeef0badc0de
-	mov rdx, 0xdeadbeef0badc0de
+	mov r8, rcx
+	mov r9, rdi
 
 global _halt
 _halt:
diff --git a/src/modules/main/main.c b/src/modules/main/main.c
index cca5512..33c7182 100644
--- a/src/modules/main/main.c
+++ b/src/modules/main/main.c
@@ -1,15 +1,7 @@
-#include "vga.h"
-
 void do_the_set_registers();
 
 void
-kernel_main()
+kernel_main(void *header)
 {
-	volatile register int foo = 0x1a1b1c10;
-	volatile register int bar = 0;
-
-	terminal_initialize(5);
-	terminal_writestring("YES HELLO THIS IS KERNEL");
-
-	do_the_set_registers();
+	do_the_set_registers(header);
 }
diff --git a/src/modules/main/vga.c b/src/modules/main/vga.c
deleted file mode 100644
index 3ebad31..0000000
--- a/src/modules/main/vga.c
+++ /dev/null
@@ -1,67 +0,0 @@
-#include "vga.h"
-
-static const size_t VGA_WIDTH = 80;
-static const size_t VGA_HEIGHT = 25;
-
-static size_t terminal_row;
-static size_t terminal_column;
-static uint8_t terminal_color;
-
-/* Note the use of the volatile keyword to prevent the compiler from eliminating dead stores. */
-static volatile uint16_t *terminal_buffer;
-
-uint8_t vga_entry_color(enum vga_color fg, enum vga_color bg);
-uint16_t vga_entry(unsigned char uc, uint8_t color);
-
-static size_t
-strlen(const char *str)
-{
-	size_t len = 0;
-	while (str[len++])
-		;
-	return len;
-}
-
-void
-terminal_initialize(size_t startrow)
-{
-	terminal_row = startrow;
-	terminal_column = 0;
-	terminal_color = vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK);
-	terminal_buffer = (uint16_t *)0xB8000;
-}
-
-void
-terminal_setcolor(uint8_t color)
-{
-	terminal_color = color;
-}
-
-void
-terminal_putentryat(char c, uint8_t color, size_t x, size_t y)
-{
-	const size_t index = y * VGA_WIDTH + x;
-	terminal_buffer[index] = vga_entry(c, color);
-}
-
-void
-terminal_putchar(char c)
-{
-	terminal_putentryat(c, terminal_color, terminal_column, terminal_row);
-	if (++terminal_column == VGA_WIDTH) {
-		terminal_column = 0;
-		if (++terminal_row == VGA_HEIGHT) terminal_row = 0;
-	}
-}
-
-void
-terminal_write(const char *data, size_t size)
-{
-	for (size_t i = 0; i < size; i++) terminal_putchar(data[i]);
-}
-
-void
-terminal_writestring(const char *data)
-{
-	terminal_write(data, strlen(data));
-}
diff --git a/src/modules/main/vga.h b/src/modules/main/vga.h
deleted file mode 100644
index 07584bd..0000000
--- a/src/modules/main/vga.h
+++ /dev/null
@@ -1,42 +0,0 @@
-#pragma once
-#include <stddef.h>
-#include <stdint.h>
-
-/* Hardware text mode color constants. */
-enum vga_color {
-	VGA_COLOR_BLACK = 0,
-	VGA_COLOR_BLUE = 1,
-	VGA_COLOR_GREEN = 2,
-	VGA_COLOR_CYAN = 3,
-	VGA_COLOR_RED = 4,
-	VGA_COLOR_MAGENTA = 5,
-	VGA_COLOR_BROWN = 6,
-	VGA_COLOR_LIGHT_GREY = 7,
-	VGA_COLOR_DARK_GREY = 8,
-	VGA_COLOR_LIGHT_BLUE = 9,
-	VGA_COLOR_LIGHT_GREEN = 10,
-	VGA_COLOR_LIGHT_CYAN = 11,
-	VGA_COLOR_LIGHT_RED = 12,
-	VGA_COLOR_LIGHT_MAGENTA = 13,
-	VGA_COLOR_LIGHT_BROWN = 14,
-	VGA_COLOR_WHITE = 15,
-};
-
-inline uint8_t
-vga_entry_color(enum vga_color fg, enum vga_color bg)
-{
-	return fg | bg << 4;
-}
-
-inline uint16_t
-vga_entry(unsigned char uc, uint8_t color)
-{
-	return (uint16_t)uc | (uint16_t)color << 8;
-}
-
-void terminal_initialize(size_t rowstart);
-void terminal_setcolor(uint8_t color);
-void terminal_putentryat(char c, uint8_t color, size_t x, size_t y);
-void terminal_putchar(char c);
-void terminal_write(const char *data, size_t size);
-void terminal_writestring(const char *data);