toaruos/kernel/main.c

/*
 * vim:tabstop=4
 * vim:noexpandtab
 * Copyright (c) 2011 Kevin Lange.  All rights reserved.
 *
 *                           Dedicated to the memory of
 *                                Dennis Ritchie
 *                                   1941-2011
 *
 * Developed by: ToAruOS Kernel Development Team
 *               http://github.com/klange/osdev
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal with the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *   1. Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimers.
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimers in the
 *      documentation and/or other materials provided with the distribution.
 *   3. Neither the names of the ToAruOS Kernel Development Team, Kevin Lange,
 *      nor the names of its contributors may be used to endorse
 *      or promote products derived from this Software without specific prior
 *      written permission.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
 * CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * WITH THE SOFTWARE.
 */

#include <system.h>
#include <boot.h>
#include <ext2.h>
#include <fs.h>

extern uintptr_t heap_end;

/*
 * kernel entry point
 *
 * This is the C entry point for the kernel.
 * It is called by the assembly loader and is passed
 * multiboot information, if available, from the bootloader.
 *
 * The kernel boot process does the following:
 * - Align the dumb allocator's heap pointer
 * - Initialize the x86 descriptor tables (global, interrupts)
 * - Initialize the interrupt handlers (ISRS, IRQ)
 * - Load up the VGA driver.
 * - Initialize the hardware drivers (PIC, keyboard)
 * - Set up paging
 * - Initialize the kernel heap (klmalloc)
 * [Further booting]
 *
 * After booting, the kernel will display its version and dump the
 * multiboot data from the bootloader. It will then proceed to print
 * out the contents of the initial ramdisk image.
 */
int main(struct multiboot *mboot, uint32_t mboot_mag, uintptr_t esp)
{
	initial_esp = esp;
	enum BOOTMODE boot_mode = unknown; /* Boot Mode */
	if (mboot_mag == MULTIBOOT_EAX_MAGIC) {
		/*
		 * Multiboot (GRUB, native QEMU, PXE)
		 */
		boot_mode = multiboot;

		mboot_ptr = mboot;

		/*
		 * Realign memory to the end of the multiboot modules
		 */
		uint32_t module_start = *((uint32_t *) mboot_ptr->mods_addr);		/* Start address */
		uint32_t module_end = *(uint32_t *) (mboot_ptr->mods_addr + 4);		/* End address */
		kmalloc_startat(module_end + 1024);

		if (mboot_ptr->flags & (1 << 3)) {
			ramdisk = (char *)module_start;
			/*
			 * Mboot modules are available.
			 */
			if (mboot_ptr->mods_count > 0) {
				/*
				 * Ramdisk image was provided. (hopefully)
				 */
				uint32_t module_start = *((uint32_t *) mboot_ptr->mods_addr);		/* Start address */
				uint32_t module_end = *(uint32_t *) (mboot_ptr->mods_addr + 4);		/* End address */
				ramdisk = (char *)kmalloc(module_end - module_start);				/* New chunk of ram for it. */
				memcpy(ramdisk, (char *)module_start, module_end - module_start);	/* Copy it over. */
			}
		}
	} else {
		/*
		 * This isn't a multiboot attempt. We were probably loaded by
		 * Mr. Boots, our dedicated boot loader. Verify this...
		 */
		boot_mode = mrboots;
	}

	/* Initialize core modules */
	init_video();		/* VGA driver */
	gdt_install();		/* Global descriptor table */
	idt_install();		/* IDT */
	isrs_install();		/* Interrupt service requests */
	irq_install();		/* Hardware interrupt requests */


	/* Memory management */
	paging_install(mboot_ptr->mem_upper);	/* Paging */
	heap_install();							/* Kernel heap */

	/* Hardware drivers */
	timer_install();	/* PIC driver */
	keyboard_install();	/* Keyboard interrupt handler */
	serial_install();	/* Serial console */

	tasking_install();	/* Multi-tasking */
	enable_fpu();		/* Enable the floating point unit */
	syscalls_install();	/* Install the system calls */

	/* Initialize the standard VGA display */
	ansi_init(&writech, 80, 25);

	if (boot_mode == multiboot) {

		if (mboot_ptr->flags & (1 << 3)) {
			/*
			 * If we have an initial ramdisk, mount it.
			 */
			if (mboot_ptr->mods_count > 0) {
				initrd_mount((uintptr_t)ramdisk, 0);
			}
		}

		/* Parse the command-line arguments */
		parse_args((char *)mboot_ptr->cmdline);
	}

	mouse_install();	/* Mouse driver */

	cls();

	start_shell();

	return 0;
}