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-rw-r--r--kernel/boot.s93
-rw-r--r--kernel/kernel.cc75
-rw-r--r--kernel/makefile2
-rw-r--r--kernel/vga.cc61
-rw-r--r--kernel/vga.h39
5 files changed, 0 insertions, 270 deletions
diff --git a/kernel/boot.s b/kernel/boot.s
deleted file mode 100644
index bb446d8..0000000
--- a/kernel/boot.s
+++ /dev/null
@@ -1,93 +0,0 @@
-/*
- Declare a multiboot header that marks the program as a kernel.
- https://www.gnu.org/software/grub/manual/multiboot2/html_node/index.html
-
- The Multiboot2 header must be contained completely within the first
- 32kB of the OS image, and must be 64-bit (8 byte) aligned.
-*/
-.set MULTIBOOT_HEADER_MAGIC, 0xe85250d6 # multiboot2 magic number
-.set MULTIBOOT_ARCHITECTURE, 0 # protected mode i386
-.set MULTIBOOT_HEADER_TAG_END, 0
-
-.section .multiboot
-.align 8
-header_start:
- .int MULTIBOOT_HEADER_MAGIC
- .int MULTIBOOT_ARCHITECTURE
- .int header_end - header_start
- .int -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_ARCHITECTURE + (header_end - header_start))
-
- # TODO tags go here
-
- .short MULTIBOOT_HEADER_TAG_END
- .short 0
- .int 8
-header_end:
-
-/*
- The stack on x86 must be 16-byte aligned according to the System V ABI
- standard and de-facto extensions. The compiler will assume the stack is
- properly aligned and failure to align the stack will result in undefined
- behavior.
-*/
-.section .stack, "aw", @nobits
-.align 16
-stack_bottom:
- .skip 16 * 1024
-stack_top:
-
-/*
- The linker script specifies _start as the entry point to the kernel and the
- bootloader will jump to this position once the kernel has been loaded.
-*/
-.section .text
-.global _start
-.type _start, @function
-_start:
- mov $stack_top, %esp # point the stack pointer to the stack
-
- /*
- This is a good place to initialize crucial processor state before the
- high-level kernel is entered. It's best to minimize the early
- environment where crucial features are offline. Note that the
- processor is not fully initialized yet: Features such as floating
- point instructions and instruction set extensions are not initialized
- yet. The GDT should be loaded here. Paging should be enabled here.
- C++ features such as global constructors and exceptions will require
- runtime support to work as well.
- */
-
- pushl %ebx # push the pointer to the multiboot structure
- pushl %eax # push the multiboot magic value
-
- /*
- Enter the high-level kernel. The ABI requires the stack is 16-byte
- aligned at the time of the call instruction (which afterwards pushes
- the return pointer of size 4 bytes). The stack was originally 16-byte
- aligned above and we've pushed a multiple of 16 bytes to the
- stack since (pushed 0 bytes so far), so the alignment has thus been
- preserved and the call is well defined.
- */
- call kernel_main
-
- /*
- If the system has nothing more to do, put the computer into an
- infinite loop. To do that:
- 1) Disable interrupts with cli (clear interrupt enable in eflags).
- They are already disabled by the bootloader, so this is not needed.
- Mind that you might later enable interrupts and return from
- kernel_main (which is sort of nonsensical to do).
- 2) Wait for the next interrupt to arrive with hlt (halt instruction).
- Since they are disabled, this will lock up the computer.
- 3) Jump to the hlt instruction if it ever wakes up due to a
- non-maskable interrupt occurring or due to system management mode.
- */
- cli
-hang: hlt
- jmp hang
-
-/*
-Set the size of the _start symbol to the current location '.' minus its start.
-This is useful when debugging or when you implement call tracing.
-*/
-.size _start, . - _start
diff --git a/kernel/kernel.cc b/kernel/kernel.cc
deleted file mode 100644
index 9ea5c95..0000000
--- a/kernel/kernel.cc
+++ /dev/null
@@ -1,75 +0,0 @@
-/* Check if the compiler thinks you are targeting the wrong operating system. */
-#if defined(__linux__)
-#error "You are not using a cross-compiler"
-#endif
-
-/* This tutorial will only work for the 32-bit ix86 targets. */
-#if !defined(__i386__)
-#error "This tutorial needs to be compiled with a ix86-elf compiler"
-#endif
-
-#include <multiboot2.h>
-#include <stdlib.h>
-#include <types.h>
-#include "vga.h"
-
-extern "C" void kernel_main(uint32_t mb_magic, uint32_t mb_addr) {
- VGA terminal;
- Console::set(&terminal);
-
- printk("Hello, kernel World!\n");
-
- printk("multiboot magic: ", uhex{mb_magic}, mb_magic == MULTIBOOT2_BOOTLOADER_MAGIC ? " valid" : " invalid", '\n');
- printk("multiboot addr: ", uhex{mb_addr}, !(mb_addr & 7) ? " is aligned" : " is not aligned", '\n');
-
- struct multiboot_tag* tag;
- const uint32_t size = *(unsigned*)mb_addr;
- printk("Announced mbi size ", size, '\n');
-
- for (tag = (struct multiboot_tag*)(mb_addr + 8); tag->type != MULTIBOOT_TAG_TYPE_END;
- tag = (struct multiboot_tag*)((multiboot_uint8_t*)tag + ((tag->size + 7) & ~7))) {
- switch (tag->type) {
- case MULTIBOOT_TAG_TYPE_CMDLINE: {
- auto* t = reinterpret_cast<multiboot_tag_string*>(tag);
- printk("Command line = [", t->string, "]\n");
- } break;
-
- case MULTIBOOT_TAG_TYPE_BOOT_LOADER_NAME: {
- auto* t = reinterpret_cast<multiboot_tag_string*>(tag);
- printk("Boot loader name = [", t->string, "]\n");
- } break;
-
- case MULTIBOOT_TAG_TYPE_BOOTDEV: {
- auto* t = reinterpret_cast<multiboot_tag_bootdev*>(tag);
- printk("Boot device ", uhex{t->biosdev}, " slice ", t->slice, " part ", t->part, '\n');
- } break;
-
- case MULTIBOOT_TAG_TYPE_BASIC_MEMINFO: {
- auto* t = reinterpret_cast<multiboot_tag_basic_meminfo*>(tag);
- printk("mem_lower = ", t->mem_lower, "KB\n", "mem_upper = ", t->mem_upper, "KB\n");
- } break;
-
- case MULTIBOOT_TAG_TYPE_MMAP: {
- auto* t = reinterpret_cast<multiboot_tag_mmap*>(tag);
- multiboot_memory_map_t* mmap;
-
- printk("memory map\n");
- for (mmap = t->entries; (multiboot_uint8_t*)mmap < (multiboot_uint8_t*)tag + tag->size;
- mmap = (multiboot_memory_map_t*)((unsigned long)mmap + ((struct multiboot_tag_mmap*)tag)->entry_size)) {
- printk(" base_addr = ", uhex{(unsigned)(mmap->addr >> 32)}, ' ', uhex{(unsigned)(mmap->addr & 0xffffffff)});
- printk(" length = ", (unsigned)(mmap->len >> 32), ' ', (unsigned)(mmap->len & 0xffffffff));
- printk(" type = ", (unsigned)mmap->type, '\n');
- }
- } break;
-
- default:
- printk("Tag ", tag->type, ", Size ", tag->size, '\n');
- break;
- } // switch(tag->type)
- } // for(each tag)
-
- tag = (struct multiboot_tag*)((multiboot_uint8_t*)tag + ((tag->size + 7) & ~7));
- printk("Total mbi size ", (unsigned)tag - mb_addr, '\n');
-
- abort();
-}
diff --git a/kernel/makefile b/kernel/makefile
deleted file mode 100644
index 23e3683..0000000
--- a/kernel/makefile
+++ /dev/null
@@ -1,2 +0,0 @@
-AS_OBJ += kernel/boot.o
-CXX_OBJ += kernel/kernel.o kernel/vga.o
diff --git a/kernel/vga.cc b/kernel/vga.cc
deleted file mode 100644
index 83d0060..0000000
--- a/kernel/vga.cc
+++ /dev/null
@@ -1,61 +0,0 @@
-#include "vga.h"
-#include <string.h>
-
-constexpr uint8_t vga_entry_color(VGA::vga_color fg, VGA::vga_color bg) {
- return fg | bg << 4;
-}
-
-constexpr uint16_t vga_entry(unsigned char uc, uint8_t color) {
- return (uint16_t)uc | (uint16_t)color << 8;
-}
-
-VGA::VGA(vga_color fg, vga_color bg, uint32_t address) {
- color = vga_entry_color(fg, bg);
- buffer = (uint16_t*)address;
-
- // clear buffer
- for (size_t y = 0; y < max_rows; y++) {
- for (size_t x = 0; x < max_columns; x++) {
- const size_t index = y * max_columns + x;
- buffer[index] = vga_entry(' ', color);
- }
- }
-}
-
-void VGA::write(char c) {
- switch (c) {
- case '\n':
- column = 0;
- ++row;
- break;
- default: {
- const size_t index = row * max_columns + column;
- buffer[index] = vga_entry(c, (color == 0) ? this->color : color);
- ++column;
- }
- }
-
- if (column == max_columns) {
- column = 0;
- ++row;
- }
-
- if (row == max_rows) {
- // scroll up - move rows 1~25 up by one
- for (size_t y = 1; y < max_rows; y++) {
- const auto prev_y = y - 1;
- for (size_t x = 0; x < max_columns; ++x) {
- const auto prev = prev_y * max_columns + x;
- const auto idx = y * max_columns + x;
- buffer[prev] = buffer[idx];
- }
- }
- --row;
- }
-}
-
-void VGA::write(ViewIterator& iter) {
- while (iter) {
- write(iter.next());
- }
-}
diff --git a/kernel/vga.h b/kernel/vga.h
deleted file mode 100644
index 3052dbc..0000000
--- a/kernel/vga.h
+++ /dev/null
@@ -1,39 +0,0 @@
-#pragma once
-#include <stdlib.h>
-
-class VGA : public Console {
-public:
- /* 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,
- };
-
- VGA(vga_color fg = VGA_COLOR_BLACK, vga_color bg = VGA_COLOR_LIGHT_GREY, uint32_t address = 0xB8000);
- ~VGA() = default;
-
- void write(char c) override;
- void write(ViewIterator& iter) override;
-
- void set_color(vga_color fg, vga_color bg) { color = (fg | bg << 4); }
-
-private:
- const size_t max_columns = 80, max_rows = 25;
- size_t column = 0, row = 0;
- uint8_t color;
- uint16_t* buffer;
-};
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