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/*
* Copyright (c) 1996-1998 University of Utah and the Flux Group.
* All rights reserved.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
/*
* Copy the do_boot stub somewhere and jump into it.
*/
#include <oskit/x86/types.h> /* oskit_size_t */
#include <oskit/x86/far_ptr.h> /* far_pointer_32 */
#include <oskit/x86/proc_reg.h> /* cli/sti */
#include <oskit/x86/base_gdt.h> /* LINEAR_CS */
#include <oskit/x86/base_vm.h> /* kvtophys */
#include <oskit/x86/pc/base_multiboot.h> /* multiboot_info_dump */
#include <oskit/c/malloc.h> /* mustmalloc */
#include <oskit/c/string.h> /* memcpy */
#include <oskit/c/stdio.h> /* printf */
#include "boot.h"
#include "debug.h"
extern char do_boot[], do_boot_end[];
void
loadkernel(struct kerninfo *ki)
{
oskit_addr_t entry, load_addr;
oskit_size_t stub_size;
void *stub;
struct far_pointer_32 ptr;
oskit_addr_t copy_source;
oskit_size_t copy_size;
#ifdef DEBUG
multiboot_info_dump(ki->ki_mbinfo);
#endif
printf("Booting kernel...\n\n");
cli();
/*
* All of the data structures that are important to the kernel,
* are in memory guaranteed not to conflict with the kernel image
* or with anything else.
* However, the kernel image itself is not in its final position,
* because that might be right on top of us,
* or on top of anything we allocated before reserving the
* kernel image region.
* Therefore, we must allocate (non-conflicting) memory for
* a small stub to copy the kernel image to its final position
* and invoke it.
*/
stub_size = do_boot_end - do_boot;
stub = mustmalloc(stub_size);
memcpy(stub, do_boot, stub_size);
ptr.seg = LINEAR_CS;
ptr.ofs = kvtophys(stub);
/*
* The kernel image source and destination regions may overlap,
* so we may have to copy either forwards or backwards.
*
* XXX the "mr" constraint for "ptr" should be "m" but GCC
* says "inconsistent operand constraints."
*
* Be careful what you put as the values for the registers in
* the asm's below.
* If you have too many indirections and whatnot then GCC
* will apparently run out of registers and won't be able to
* set, for example, %ebx to the desired value.
* The GCC chokeage looked like this for me:
*
* fixed or forbidden register was spilled.
* This may be due to a compiler bug or to impossible asm
*
* That is why I have load_addr and entry be local vars instead of
* just putting the expressions in the asm.
*/
copy_source = kvtophys(ki->ki_imgaddr);
copy_size = kerninfo_imagesize(ki);
entry = ki->ki_mbhdr.entry;
load_addr = ki->ki_mbhdr.load_addr;
dprintf("ki->ki_mbinfo = %p-%p\n",
kvtophys(ki->ki_mbinfo),
kvtophys(ki->ki_mbinfo) + sizeof(ki->ki_mbinfo));
dprintf("stub = %p-%p\n", stub, stub + stub_size);
if (copy_source > load_addr) {
asm volatile("
cld
ljmp %0
" : /* no outputs */
: "mr" (ptr),
"a" (entry),
"S" (copy_source),
"D" (load_addr),
"c" (copy_size),
"b" (kvtophys(ki->ki_mbinfo)),
"d" (LINEAR_DS));
}
else {
asm volatile("
std
ljmp %0
" : /* no outputs */
: "mr" (ptr),
"a" (entry),
"S" (copy_source + copy_size - 1),
"D" (load_addr + copy_size - 1),
"c" (copy_size),
"b" (kvtophys(ki->ki_mbinfo)),
"d" (LINEAR_DS));
}
}
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