/* ----------------------------------------------------------------------- *
*
* Copyright 2007-2009 H. Peter Anvin - All Rights Reserved
* Copyright 2009 Intel Corporation; author: H. Peter Anvin
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in 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:
*
* The above copyright notice and this permission notice shall
* be included in all copies or substantial portions of the Software.
*
* 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 AUTHORS 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 IN THE SOFTWARE.
*
* ----------------------------------------------------------------------- */
/*
* shuffle.c
*
* Common code for "shuffle and boot" operation; generates a shuffle list
* and puts it in the bounce buffer. Returns the number of shuffle
* descriptors.
*/
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
#include <com32.h>
#include <minmax.h>
#include <syslinux/movebits.h>
#include <klibc/compiler.h>
#ifndef DEBUG
# define DEBUG 0
#endif
#define dprintf(f, ...) ((void)0)
#define dprintf2(f, ...) ((void)0)
#if DEBUG
# include <stdio.h>
# undef dprintf
# define dprintf printf
# if DEBUG > 1
# undef dprintf2
# define dprintf2 printf
# endif
#endif
struct shuffle_descriptor {
uint32_t dst, src, len;
};
static int shuffler_size;
static void __constructor __syslinux_get_shuffer_size(void)
{
static com32sys_t reg;
reg.eax.w[0] = 0x0023;
__intcall(0x22, ®, ®);
shuffler_size = (reg.eflags.l & EFLAGS_CF) ? 2048 : reg.ecx.w[0];
}
/*
* Allocate descriptor memory in these chunks; if this is large we may
* waste memory, if it is small we may get slow convergence.
*/
#define DESC_BLOCK_SIZE 256
int syslinux_do_shuffle(struct syslinux_movelist *fraglist,
struct syslinux_memmap *memmap,
addr_t entry_point, addr_t entry_type,
uint16_t bootflags)
{
int rv = -1;
struct syslinux_movelist *moves = NULL, *mp;
struct syslinux_memmap *rxmap = NULL, *ml;
struct shuffle_descriptor *dp, *dbuf;
int np;
int desc_blocks, need_blocks;
int need_ptrs;
addr_t desczone, descfree, descaddr, descoffs;
int nmoves, nzero;
com32sys_t ireg;
descaddr = 0;
dp = dbuf = NULL;
/* Count the number of zero operations */
nzero = 0;
for (ml = memmap; ml->type != SMT_END; ml = ml->next) {
if (ml->type == SMT_ZERO)
nzero++;
}
/* Find the largest contiguous region unused by input *and* output;
this is where we put the move descriptor list and safe area */
rxmap = syslinux_dup_memmap(memmap);
if (!rxmap)
goto bail;
/* Avoid using the low 1 MB for the shuffle area -- this avoids
possible interference with the real mode code or stack */
if (syslinux_add_memmap(&rxmap, 0, 1024 * 1024, SMT_RESERVED))
goto bail;
for (mp = fraglist; mp; mp = mp->next) {
if (syslinux_add_memmap(&rxmap, mp->src, mp->len, SMT_ALLOC) ||
syslinux_add_memmap(&rxmap, mp->dst, mp->len, SMT_ALLOC))
goto bail;
}
if (syslinux_memmap_largest(rxmap, SMT_FREE, &desczone, &descfree))
goto bail;
syslinux_free_memmap(rxmap);
dprintf("desczone = 0x%08x, descfree = 0x%08x\n", desczone, descfree);
rxmap = syslinux_dup_memmap(memmap);
if (!rxmap)
goto bail;
desc_blocks = (nzero + DESC_BLOCK_SIZE - 1) / DESC_BLOCK_SIZE;
for (;;) {
/* We want (desc_blocks) allocation blocks, plus the terminating
descriptor, plus the shuffler safe area. */
addr_t descmem = desc_blocks *
sizeof(struct shuffle_descriptor) * DESC_BLOCK_SIZE
+ sizeof(struct shuffle_descriptor) + shuffler_size;
descaddr = (desczone + descfree - descmem) & ~3;
if (descaddr < desczone)
goto bail; /* No memory block large enough */
/* Mark memory used by shuffle descriptors as reserved */
if (syslinux_add_memmap(&rxmap, descaddr, descmem, SMT_RESERVED))
goto bail;
#if DEBUG > 1
syslinux_dump_movelist(stdout, fraglist);
#endif
if (syslinux_compute_movelist(&moves, fraglist, rxmap))
goto bail;
nmoves = 0;
for (mp = moves; mp; mp = mp->next)
nmoves++;
need_blocks = (nmoves + nzero + DESC_BLOCK_SIZE - 1) / DESC_BLOCK_SIZE;
if (desc_blocks >= need_blocks)
break; /* Sufficient memory, yay */
desc_blocks = need_blocks; /* Try again... */
}
#if DEBUG > 1
dprintf("Final movelist:\n");
syslinux_dump_movelist(stdout, moves);
#endif
syslinux_free_memmap(rxmap);
rxmap = NULL;
need_ptrs = nmoves + nzero + 1;
dbuf = malloc(need_ptrs * sizeof(struct shuffle_descriptor));
if (!dbuf)
goto bail;
descoffs = descaddr - (addr_t) dbuf;
#if DEBUG
dprintf("nmoves = %d, nzero = %d, dbuf = %p, offs = 0x%08x\n",
nmoves, nzero, dbuf, descoffs);
#endif
/* Copy the move sequence into the descriptor buffer */
np = 0;
dp = dbuf;
for (mp = moves; mp; mp = mp->next) {
dp->dst = mp->dst;
dp->src = mp->src;
dp->len = mp->len;
dprintf2("[ %08x %08x %08x ]\n", dp->dst, dp->src, dp->len);
dp++;
np++;
}
/* Copy bzero operations into the descriptor buffer */
for (ml = memmap; ml->type != SMT_END; ml = ml->next) {
if (ml->type == SMT_ZERO) {
dp->dst = ml->start;
dp->src = (addr_t) - 1; /* bzero region */
dp->len = ml->next->start - ml->start;
dprintf2("[ %08x %08x %08x ]\n", dp->dst, dp->src, dp->len);
dp++;
np++;
}
}
/* Finally, record the termination entry */
dp->dst = entry_point;
dp->src = entry_type;
dp->len = 0;
dp++;
np++;
if (np != need_ptrs) {
dprintf("!!! np = %d : nmoves = %d, nzero = %d, desc_blocks = %d\n",
np, nmoves, nzero, desc_blocks);
}
rv = 0;
bail:
/* This is safe only because free() doesn't use the bounce buffer!!!! */
if (moves)
syslinux_free_movelist(moves);
if (rxmap)
syslinux_free_memmap(rxmap);
if (rv)
return rv;
/* Actually do it... */
memset(&ireg, 0, sizeof ireg);
ireg.edi.l = descaddr;
ireg.esi.l = (addr_t) dbuf;
ireg.ecx.l = (addr_t) dp - (addr_t) dbuf;
ireg.edx.w[0] = bootflags;
ireg.eax.w[0] = 0x0024;
__intcall(0x22, &ireg, NULL);
return -1; /* Shouldn't have returned! */
}
/*
* Common helper routine: takes a memory map and blots out the
* zones which are used in the destination of a fraglist
*/
struct syslinux_memmap *syslinux_target_memmap(struct syslinux_movelist
*fraglist,
struct syslinux_memmap *memmap)
{
struct syslinux_memmap *tmap;
struct syslinux_movelist *mp;
tmap = syslinux_dup_memmap(memmap);
if (!tmap)
return NULL;
for (mp = fraglist; mp; mp = mp->next) {
if (syslinux_add_memmap(&tmap, mp->dst, mp->len, SMT_ALLOC)) {
syslinux_free_memmap(tmap);
return NULL;
}
}
return tmap;
}
