mirror of https://github.com/dzavalishin/oskit/
100 lines
3.2 KiB
C
100 lines
3.2 KiB
C
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/*
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* Copyright (c) 1996, 1998 University of Utah and the Flux Group.
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* All rights reserved.
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*
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* This file is part of the Flux OSKit. The OSKit is free software, also known
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* as "open source;" you can redistribute it and/or modify it under the terms
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* of the GNU General Public License (GPL), version 2, as published by the Free
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* Software Foundation (FSF). To explore alternate licensing terms, contact
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* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
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*
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* The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
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* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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* FOR A PARTICULAR PURPOSE. See the GPL for more details. You should have
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* received a copy of the GPL along with the OSKit; see the file COPYING. If
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* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
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*/
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/*
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* Copy the kernel somewhere and jump in.
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*/
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#include <oskit/x86/types.h> /* oskit_size_t */
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#include <oskit/x86/far_ptr.h> /* far_pointer_32 */
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#include <oskit/x86/proc_reg.h> /* cli/sti */
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#include <oskit/x86/base_gdt.h> /* LINEAR_CS */
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#include <oskit/x86/base_vm.h> /* kvtophys */
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#include <oskit/x86/pc/base_multiboot.h> /* multiboot_info_dump */
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#include <oskit/c/malloc.h> /* mustmalloc */
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#include <oskit/c/strings.h> /* bcopy */
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#include <oskit/c/stdio.h> /* printf */
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#include "boot.h" /* boot_info */
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extern char do_boot[], do_boot_end[];
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void boot_start(struct multiboot_info *bi)
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{
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oskit_size_t stub_size;
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void *stub;
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struct far_pointer_32 ptr;
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oskit_addr_t copy_source;
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oskit_size_t copy_size;
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#ifdef DEBUG
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multiboot_info_dump(bi);
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#endif
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printf("Booting kernel...\n\n");
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cli();
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/* All of the data structures that are important to the kernel,
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are in memory guaranteed not to conflict with the kernel image
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or with anything else.
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However, the kernel image itself is not in its final position,
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because that might be right on top of us,
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or on top of anything we allocated before reserving the kernel image region.
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Therefore, we must allocate (non-conflicting) memory for a small stub
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to copy the kernel image to its final position and invoke it. */
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stub_size = do_boot_end - do_boot;
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stub = mustmalloc(stub_size);
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bcopy(do_boot, stub, stub_size);
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ptr.seg = LINEAR_CS;
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ptr.ofs = kvtophys(stub);
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/* The kernel image source and destination regions may overlap,
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so we may have to copy either forwards or backwards. */
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copy_source = kvtophys(boot_kern_image);
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copy_size = boot_kern_hdr.load_end_addr - boot_kern_hdr.load_addr;
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if (copy_source > boot_kern_hdr.load_addr)
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{
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asm volatile("
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cld
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ljmp %0
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" :
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: "mr" (ptr), /* XXX r is inappropriate but gcc wants it */
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"a" (boot_kern_hdr.entry),
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"S" (copy_source),
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"D" (boot_kern_hdr.load_addr),
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"c" (copy_size),
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"b" (kvtophys(bi)),
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"d" (LINEAR_DS));
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}
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else
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{
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printf("(copying backwards...)\n"); /* XXX */
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asm volatile("
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std
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ljmp %0
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" :
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: "mr" (ptr), /* XXX r is inappropriate but gcc wants it */
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"a" (boot_kern_hdr.entry),
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"S" (copy_source + copy_size - 1),
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"D" (boot_kern_hdr.load_addr + copy_size - 1),
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"c" (copy_size),
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"b" (kvtophys(bi)),
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"d" (LINEAR_DS));
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}
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}
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