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-rw-r--r--contrib/syslinux-4.02/com32/lib/syslinux/movebits.c710
1 files changed, 710 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/com32/lib/syslinux/movebits.c b/contrib/syslinux-4.02/com32/lib/syslinux/movebits.c
new file mode 100644
index 0000000..bd5ce0e
--- /dev/null
+++ b/contrib/syslinux-4.02/com32/lib/syslinux/movebits.c
@@ -0,0 +1,710 @@
+/* ----------------------------------------------------------------------- *
+ *
+ * Copyright 2007-2008 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.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * movebits.c
+ *
+ * Utility function to take a list of memory areas to shuffle and
+ * convert it to a set of shuffle operations.
+ *
+ * Note: a lot of the functions in this file deal with "parent pointers",
+ * which are pointers to a pointer to a list, or part of the list.
+ * They can be pointers to a variable holding the list root pointer,
+ * or pointers to a next field of a previous entry.
+ */
+
+#include <assert.h>
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <inttypes.h>
+#include <setjmp.h>
+#include <minmax.h>
+#include <stdbool.h>
+
+#include <syslinux/movebits.h>
+
+#ifndef DEBUG
+# ifdef TEST
+# define DEBUG 1
+# else
+# define DEBUG 0
+# endif
+#endif
+
+#if DEBUG
+# include <stdio.h>
+# define dprintf printf
+#else
+# define dprintf(...) ((void)0)
+#endif
+
+static jmp_buf new_movelist_bail;
+
+static struct syslinux_movelist *new_movelist(addr_t dst, addr_t src,
+ addr_t len)
+{
+ struct syslinux_movelist *ml = malloc(sizeof(struct syslinux_movelist));
+
+ if (!ml)
+ longjmp(new_movelist_bail, 1);
+
+ ml->dst = dst;
+ ml->src = src;
+ ml->len = len;
+ ml->next = NULL;
+
+ return ml;
+}
+
+static struct syslinux_movelist *dup_movelist(struct syslinux_movelist *src)
+{
+ struct syslinux_movelist *dst = NULL, **dstp = &dst, *ml;
+
+ while (src) {
+ ml = new_movelist(src->dst, src->src, src->len);
+ *dstp = ml;
+ dstp = &ml->next;
+ src = src->next;
+ }
+
+ return dst;
+}
+
+static void
+add_freelist(struct syslinux_memmap **mmap, addr_t start,
+ addr_t len, enum syslinux_memmap_types type)
+{
+ if (syslinux_add_memmap(mmap, start, len, type))
+ longjmp(new_movelist_bail, 1);
+}
+
+/*
+ * Take a chunk, entirely confined in **parentptr, and split it off so that
+ * it has its own structure.
+ */
+static struct syslinux_movelist **split_movelist(addr_t start, addr_t len,
+ struct syslinux_movelist
+ **parentptr)
+{
+ struct syslinux_movelist *m, *ml = *parentptr;
+
+ assert(start >= ml->src);
+ assert(start < ml->src + ml->len);
+
+ /* Split off the beginning */
+ if (start > ml->src) {
+ addr_t l = start - ml->src;
+
+ m = new_movelist(ml->dst + l, start, ml->len - l);
+ m->next = ml->next;
+ ml->len = l;
+ ml->next = m;
+
+ parentptr = &ml->next;
+ ml = m; /* Continue processing the new node */
+ }
+
+ /* Split off the end */
+ if (ml->len > len) {
+ addr_t l = ml->len - len;
+
+ m = new_movelist(ml->dst + len, ml->src + len, l);
+ m->next = ml->next;
+ ml->len = len;
+ ml->next = m;
+ }
+
+ return parentptr;
+}
+
+static void delete_movelist(struct syslinux_movelist **parentptr)
+{
+ struct syslinux_movelist *o = *parentptr;
+ *parentptr = o->next;
+ free(o);
+}
+
+static void free_movelist(struct syslinux_movelist **parentptr)
+{
+ while (*parentptr)
+ delete_movelist(parentptr);
+}
+
+/*
+ * Scan the freelist looking for a particular chunk of memory
+ */
+static const struct syslinux_memmap *is_free_zone(const struct syslinux_memmap
+ *list, addr_t start,
+ addr_t len)
+{
+ dprintf("f: 0x%08x bytes at 0x%08x\n", len, start);
+
+ addr_t last, llast;
+
+ last = start + len - 1;
+
+ while (list->type != SMT_END) {
+ llast = list->next->start - 1;
+ if (list->start <= start) {
+ if (llast >= last) {
+ /* Chunk has a single, well-defined type */
+ if (list->type == SMT_FREE) {
+ dprintf("F: 0x%08x bytes at 0x%08x\n",
+ list->next->start, list->start);
+ return list; /* It's free */
+ }
+ return NULL; /* Not free */
+ } else if (llast >= start) {
+ return NULL; /* Crosses region boundary */
+ }
+ }
+ list = list->next;
+ }
+
+ return NULL; /* Internal error? */
+}
+
+/*
+ * Scan the freelist looking for the smallest chunk of memory which
+ * can fit X bytes; returns the length of the block on success.
+ */
+static addr_t free_area(const struct syslinux_memmap *mmap,
+ addr_t len, addr_t * start)
+{
+ const struct syslinux_memmap *best = NULL;
+ const struct syslinux_memmap *s;
+ addr_t slen, best_len = -1;
+
+ for (s = mmap; s->type != SMT_END; s = s->next) {
+ if (s->type != SMT_FREE)
+ continue;
+ slen = s->next->start - s->start;
+ if (slen >= len) {
+ if (!best || best_len > slen) {
+ best = s;
+ best_len = slen;
+ }
+ }
+ }
+
+ if (best) {
+ *start = best->start;
+ return best_len;
+ } else {
+ return 0;
+ }
+}
+
+/*
+ * Remove a chunk from the freelist
+ */
+static void
+allocate_from(struct syslinux_memmap **mmap, addr_t start, addr_t len)
+{
+ syslinux_add_memmap(mmap, start, len, SMT_ALLOC);
+}
+
+/*
+ * Find chunks of a movelist which are one-to-many (one source, multiple
+ * destinations.) Those chunks can get turned into post-shuffle copies,
+ * to avoid confusing the shuffler.
+ */
+static void shuffle_dealias(struct syslinux_movelist **fraglist,
+ struct syslinux_movelist **postcopy)
+{
+ struct syslinux_movelist *mp, **mpp, *mx, *np;
+ addr_t ps, pe, xs, xe, delta;
+ bool advance;
+
+#if DEBUG
+ dprintf("Before alias resolution:\n");
+ syslinux_dump_movelist(stdout, *fraglist);
+#endif
+
+ *postcopy = NULL;
+
+ /*
+ * Note: as written, this is an O(n^2) algorithm; by producing a list
+ * sorted by destination address we could reduce it to O(n log n).
+ */
+ mpp = fraglist;
+ while ((mp = *mpp)) {
+ dprintf("mp -> (%#x,%#x,%#x)\n", mp->dst, mp->src, mp->len);
+ ps = mp->src;
+ pe = mp->src + mp->len - 1;
+ for (mx = *fraglist; mx != mp; mx = mx->next) {
+ dprintf("mx -> (%#x,%#x,%#x)\n", mx->dst, mx->src, mx->len);
+ /*
+ * If there is any overlap between mx and mp, mp should be
+ * modified and possibly split.
+ */
+ xs = mx->src;
+ xe = mx->src + mx->len - 1;
+
+ dprintf("?: %#x..%#x (inside %#x..%#x)\n", ps, pe, xs, xe);
+
+ if (pe <= xs || ps >= xe)
+ continue; /* No overlap */
+
+ advance = false;
+ *mpp = mp->next; /* Remove from list */
+
+ if (pe > xe) {
+ delta = pe - xe;
+ np = new_movelist(mp->dst + mp->len - delta,
+ mp->src + mp->len - delta, delta);
+ mp->len -= delta;
+ pe = xe;
+ np->next = *mpp;
+ *mpp = np;
+ advance = true;
+ }
+ if (ps < xs) {
+ delta = xs - ps;
+ np = new_movelist(mp->dst, ps, delta);
+ mp->src += delta;
+ ps = mp->src;
+ mp->dst += delta;
+ mp->len -= delta;
+ np->next = *mpp;
+ *mpp = np;
+ advance = true;
+ }
+
+ assert(ps >= xs && pe <= xe);
+
+ dprintf("Overlap: %#x..%#x (inside %#x..%#x)\n", ps, pe, xs, xe);
+
+ mp->src = mx->dst + (ps - xs);
+ mp->next = *postcopy;
+ *postcopy = mp;
+
+ mp = *mpp;
+
+ if (!advance)
+ goto restart;
+ }
+
+ mpp = &mp->next;
+restart:
+ ;
+ }
+
+#if DEBUG
+ dprintf("After alias resolution:\n");
+ syslinux_dump_movelist(stdout, *fraglist);
+ dprintf("Post-shuffle copies:\n");
+ syslinux_dump_movelist(stdout, *postcopy);
+#endif
+}
+
+/*
+ * The code to actually emit moving of a chunk into its final place.
+ */
+static void
+move_chunk(struct syslinux_movelist ***moves,
+ struct syslinux_memmap **mmap,
+ struct syslinux_movelist **fp, addr_t copylen)
+{
+ addr_t copydst, copysrc;
+ addr_t freebase, freelen;
+ addr_t needlen;
+ int reverse;
+ struct syslinux_movelist *f = *fp, *mv;
+
+ if (f->src < f->dst && (f->dst - f->src) < f->len) {
+ /* "Shift up" type overlap */
+ needlen = f->dst - f->src;
+ reverse = 1;
+ } else if (f->src > f->dst && (f->src - f->dst) < f->len) {
+ /* "Shift down" type overlap */
+ needlen = f->src - f->dst;
+ reverse = 0;
+ } else {
+ needlen = f->len;
+ reverse = 0;
+ }
+
+ copydst = f->dst;
+ copysrc = f->src;
+
+ dprintf("Q: copylen = 0x%08x, needlen = 0x%08x\n", copylen, needlen);
+
+ if (copylen < needlen) {
+ if (reverse) {
+ copydst += (f->len - copylen);
+ copysrc += (f->len - copylen);
+ }
+
+ dprintf("X: 0x%08x bytes at 0x%08x -> 0x%08x\n",
+ copylen, copysrc, copydst);
+
+ /* Didn't get all we wanted, so we have to split the chunk */
+ fp = split_movelist(copysrc, copylen, fp); /* Is this right? */
+ f = *fp;
+ }
+
+ mv = new_movelist(f->dst, f->src, f->len);
+ dprintf("A: 0x%08x bytes at 0x%08x -> 0x%08x\n", mv->len, mv->src, mv->dst);
+ **moves = mv;
+ *moves = &mv->next;
+
+ /* Figure out what memory we just freed up */
+ if (f->dst > f->src) {
+ freebase = f->src;
+ freelen = min(f->len, f->dst - f->src);
+ } else if (f->src >= f->dst + f->len) {
+ freebase = f->src;
+ freelen = f->len;
+ } else {
+ freelen = f->src - f->dst;
+ freebase = f->dst + f->len;
+ }
+
+ dprintf("F: 0x%08x bytes at 0x%08x\n", freelen, freebase);
+
+ add_freelist(mmap, freebase, freelen, SMT_FREE);
+
+ delete_movelist(fp);
+}
+
+/*
+ * moves is computed from "frags" and "freemem". "space" lists
+ * free memory areas at our disposal, and is (src, cnt) only.
+ */
+int
+syslinux_compute_movelist(struct syslinux_movelist **moves,
+ struct syslinux_movelist *ifrags,
+ struct syslinux_memmap *memmap)
+{
+ struct syslinux_memmap *mmap = NULL;
+ const struct syslinux_memmap *mm, *ep;
+ struct syslinux_movelist *frags = NULL;
+ struct syslinux_movelist *postcopy = NULL;
+ struct syslinux_movelist *mv;
+ struct syslinux_movelist *f, **fp;
+ struct syslinux_movelist *o, **op;
+ addr_t needbase, needlen, copysrc, copydst, copylen;
+ addr_t avail;
+ addr_t fstart, flen;
+ addr_t cbyte;
+ addr_t ep_len;
+ int rv = -1;
+ int reverse;
+
+ dprintf("entering syslinux_compute_movelist()...\n");
+
+ if (setjmp(new_movelist_bail)) {
+nomem:
+ dprintf("Out of working memory!\n");
+ goto bail;
+ }
+
+ *moves = NULL;
+
+ /* Create our memory map. Anything that is SMT_FREE or SMT_ZERO is
+ fair game, but mark anything used by source material as SMT_ALLOC. */
+ mmap = syslinux_init_memmap();
+ if (!mmap)
+ goto nomem;
+
+ frags = dup_movelist(ifrags);
+
+ /* Process one-to-many conditions */
+ shuffle_dealias(&frags, &postcopy);
+
+ for (mm = memmap; mm->type != SMT_END; mm = mm->next)
+ add_freelist(&mmap, mm->start, mm->next->start - mm->start,
+ mm->type == SMT_ZERO ? SMT_FREE : mm->type);
+
+ for (f = frags; f; f = f->next)
+ add_freelist(&mmap, f->src, f->len, SMT_ALLOC);
+
+ /* As long as there are unprocessed fragments in the chain... */
+ while ((fp = &frags, f = *fp)) {
+
+#if DEBUG
+ dprintf("Current free list:\n");
+ syslinux_dump_memmap(stdout, mmap);
+ dprintf("Current frag list:\n");
+ syslinux_dump_movelist(stdout, frags);
+#endif
+
+ /* Scan for fragments which can be discarded without action. */
+ if (f->src == f->dst) {
+ delete_movelist(fp);
+ continue;
+ }
+ op = &f->next;
+ while ((o = *op)) {
+ if (o->src == o->dst)
+ delete_movelist(op);
+ else
+ op = &o->next;
+ }
+
+ /* Scan for fragments which can be immediately moved
+ to their final destination, if so handle them now */
+ for (op = fp; (o = *op); op = &o->next) {
+ if (o->src < o->dst && (o->dst - o->src) < o->len) {
+ /* "Shift up" type overlap */
+ needlen = o->dst - o->src;
+ needbase = o->dst + (o->len - needlen);
+ reverse = 1;
+ cbyte = o->dst + o->len - 1;
+ } else if (o->src > o->dst && (o->src - o->dst) < o->len) {
+ /* "Shift down" type overlap */
+ needlen = o->src - o->dst;
+ needbase = o->dst;
+ reverse = 0;
+ cbyte = o->dst; /* "Critical byte" */
+ } else {
+ needlen = o->len;
+ needbase = o->dst;
+ reverse = 0;
+ cbyte = o->dst; /* "Critical byte" */
+ }
+
+ if (is_free_zone(mmap, needbase, needlen)) {
+ fp = op, f = o;
+ dprintf("!: 0x%08x bytes at 0x%08x -> 0x%08x\n",
+ f->len, f->src, f->dst);
+ copysrc = f->src;
+ copylen = needlen;
+ allocate_from(&mmap, needbase, copylen);
+ goto move_chunk;
+ }
+ }
+
+ /* Ok, bother. Need to do real work at least with one chunk. */
+
+ dprintf("@: 0x%08x bytes at 0x%08x -> 0x%08x\n",
+ f->len, f->src, f->dst);
+
+ /* See if we can move this chunk into place by claiming
+ the destination, or in the case of partial overlap, the
+ missing portion. */
+
+ if (f->src < f->dst && (f->dst - f->src) < f->len) {
+ /* "Shift up" type overlap */
+ needlen = f->dst - f->src;
+ needbase = f->dst + (f->len - needlen);
+ reverse = 1;
+ cbyte = f->dst + f->len - 1;
+ } else if (f->src > f->dst && (f->src - f->dst) < f->len) {
+ /* "Shift down" type overlap */
+ needlen = f->src - f->dst;
+ needbase = f->dst;
+ reverse = 0;
+ cbyte = f->dst; /* "Critical byte" */
+ } else {
+ needlen = f->len;
+ needbase = f->dst;
+ reverse = 0;
+ cbyte = f->dst;
+ }
+
+ dprintf("need: base = 0x%08x, len = 0x%08x, "
+ "reverse = %d, cbyte = 0x%08x\n",
+ needbase, needlen, reverse, cbyte);
+
+ ep = is_free_zone(mmap, cbyte, 1);
+ if (ep) {
+ ep_len = ep->next->start - ep->start;
+ if (reverse)
+ avail = needbase + needlen - ep->start;
+ else
+ avail = ep_len - (needbase - ep->start);
+ } else {
+ avail = 0;
+ }
+
+ if (avail) {
+ /* We can move at least part of this chunk into place without
+ further ado */
+ dprintf("space: start 0x%08x, len 0x%08x, free 0x%08x\n",
+ ep->start, ep_len, avail);
+ copylen = min(needlen, avail);
+
+ if (reverse)
+ allocate_from(&mmap, needbase + needlen - copylen, copylen);
+ else
+ allocate_from(&mmap, needbase, copylen);
+
+ goto move_chunk;
+ }
+
+ /* At this point, we need to evict something out of our space.
+ Find the object occupying the critical byte of our target space,
+ and move it out (the whole object if we can, otherwise a subset.)
+ Then move a chunk of ourselves into place. */
+ for (op = &f->next, o = *op; o; op = &o->next, o = *op) {
+
+ dprintf("O: 0x%08x bytes at 0x%08x -> 0x%08x\n",
+ o->len, o->src, o->dst);
+
+ if (!(o->src <= cbyte && o->src + o->len > cbyte))
+ continue; /* Not what we're looking for... */
+
+ /* Find somewhere to put it... */
+
+ if (is_free_zone(mmap, o->dst, o->len)) {
+ /* Score! We can move it into place directly... */
+ copydst = o->dst;
+ copysrc = o->src;
+ copylen = o->len;
+ } else if (free_area(mmap, o->len, &fstart)) {
+ /* We can move the whole chunk */
+ copydst = fstart;
+ copysrc = o->src;
+ copylen = o->len;
+ } else {
+ /* Well, copy as much as we can... */
+ if (syslinux_memmap_largest(mmap, SMT_FREE, &fstart, &flen)) {
+ dprintf("No free memory at all!\n");
+ goto bail; /* Stuck! */
+ }
+
+ /* Make sure we include the critical byte */
+ copydst = fstart;
+ if (reverse) {
+ copysrc = max(o->src, cbyte + 1 - flen);
+ copylen = cbyte + 1 - copysrc;
+ } else {
+ copysrc = cbyte;
+ copylen = min(flen, o->len - (cbyte - o->src));
+ }
+ }
+ allocate_from(&mmap, copydst, copylen);
+
+ if (copylen < o->len) {
+ op = split_movelist(copysrc, copylen, op);
+ o = *op;
+ }
+
+ mv = new_movelist(copydst, copysrc, copylen);
+ dprintf("C: 0x%08x bytes at 0x%08x -> 0x%08x\n",
+ mv->len, mv->src, mv->dst);
+ *moves = mv;
+ moves = &mv->next;
+
+ o->src = copydst;
+
+ if (copylen > needlen) {
+ /* We don't need all the memory we freed up. Mark it free. */
+ if (copysrc < needbase) {
+ add_freelist(&mmap, copysrc, needbase - copysrc, SMT_FREE);
+ copylen -= (needbase - copysrc);
+ }
+ if (copylen > needlen) {
+ add_freelist(&mmap, copysrc + needlen, copylen - needlen,
+ SMT_FREE);
+ copylen = needlen;
+ }
+ }
+ reverse = 0;
+ goto move_chunk;
+ }
+ dprintf("Cannot find the chunk containing the critical byte\n");
+ goto bail; /* Stuck! */
+
+move_chunk:
+ move_chunk(&moves, &mmap, fp, copylen);
+ }
+
+ /* Finally, append the postcopy chain to the end of the moves list */
+ for (op = moves; (o = *op); op = &o->next) ; /* Locate the end of the list */
+ *op = postcopy;
+ postcopy = NULL;
+
+ rv = 0;
+bail:
+ if (mmap)
+ syslinux_free_memmap(mmap);
+ if (frags)
+ free_movelist(&frags);
+ if (postcopy)
+ free_movelist(&postcopy);
+ return rv;
+}
+
+#ifdef TEST
+
+#include <stdio.h>
+
+int main(int argc, char *argv[])
+{
+ FILE *f;
+ unsigned long d, s, l;
+ struct syslinux_movelist *frags;
+ struct syslinux_movelist **fep = &frags;
+ struct syslinux_movelist *mv, *moves;
+ struct syslinux_memmap *memmap;
+ char line[BUFSIZ];
+
+ (void)argc;
+
+ memmap = syslinux_init_memmap();
+
+ f = fopen(argv[1], "r");
+ while (fgets(line, sizeof line, f) != NULL) {
+ if (sscanf(line, "%lx %lx %lx", &s, &d, &l) == 3) {
+ if (d) {
+ if (s == -1UL) {
+ syslinux_add_memmap(&memmap, d, l, SMT_ZERO);
+ } else {
+ mv = new_movelist(d, s, l);
+ *fep = mv;
+ fep = &mv->next;
+ }
+ } else {
+ syslinux_add_memmap(&memmap, s, l, SMT_FREE);
+ }
+ }
+ }
+ fclose(f);
+
+ *fep = NULL;
+
+ printf("Input move list:\n");
+ syslinux_dump_movelist(stdout, frags);
+ printf("Input free list:\n");
+ syslinux_dump_memmap(stdout, memmap);
+
+ if (syslinux_compute_movelist(&moves, frags, memmap)) {
+ printf("Failed to compute a move sequence\n");
+ return 1;
+ } else {
+ printf("Final move list:\n");
+ syslinux_dump_movelist(stdout, moves);
+ return 0;
+ }
+}
+
+#endif /* TEST */
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-05-21 00:44:34 +0200