[src/trunk]: src/sys/arch/amiga/stand/bootblock/elf2bb For upcoming FFSv2 sup...

[rin <rin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ba6dcb345977
branches:  trunk
changeset: 1019047:ba6dcb345977
user:      rin <rin%NetBSD.org@localhost>
date:      Thu Feb 25 03:40:27 2021 +0000

description:
For upcoming FFSv2 support for boot.amiga, dynamically scale its size,
instead of fixing to 32KB.

Old 32KB limit comes from

(1) all R_68K_PC16 symbols get relocated, and

(2) all values in our relocation table for R_68K_32 symbols fit within
    16-bit integer.

(1) is already checked in the code. Assertion for (2) is added, but this
limit is satisfied with sufficient margin at the moment. If it is not the
case in the future, we may need to change format for relocation table.

diffstat:

 sys/arch/amiga/stand/bootblock/elf2bb/elf2bb.c |  85 ++++++++++++++++++-------
 1 files changed, 60 insertions(+), 25 deletions(-)

diffs (156 lines):

diff -r c71d56122915 -r ba6dcb345977 sys/arch/amiga/stand/bootblock/elf2bb/elf2bb.c
--- a/sys/arch/amiga/stand/bootblock/elf2bb/elf2bb.c    Thu Feb 25 01:07:43 2021 +0000
+++ b/sys/arch/amiga/stand/bootblock/elf2bb/elf2bb.c    Thu Feb 25 03:40:27 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: elf2bb.c,v 1.17 2020/08/20 15:54:12 riastradh Exp $    */
+/*     $NetBSD: elf2bb.c,v 1.18 2021/02/25 03:40:27 rin Exp $  */
 
 /*-
  * Copyright (c) 1996,2006 The NetBSD Foundation, Inc.
@@ -33,6 +33,7 @@
 #include "nbtool_config.h"
 #endif
 
+#include <sys/param.h>
 #include <sys/types.h>
 
 #include <err.h>
@@ -111,6 +112,7 @@
        int undefsyms;
        uint32_t tmp32;
        uint16_t tmp16;
+       int Sflag = 0;
 
        progname = argv[0];
 
@@ -122,7 +124,7 @@
                break;
        case 'S':
                /* Dynamically size second-stage boot */
-               sumsize = 0;
+               Sflag = 1;
                break;
        case 'd':
                debug = 1;
@@ -155,7 +157,7 @@
                    htobe16(eh->e_machine));
 
        /* Calculate sizes from section headers. */
-       tsz = dsz = bsz = trsz = pcrelsz = r32sz = 0;
+       tsz = dsz = bsz = trsz = 0;
        sh = (Elf32_Shdr *)(image + htobe32(eh->e_shoff));
        shstrtab = (char *)(image + htobe32(sh[htobe16(eh->e_shstrndx)].sh_offset));
        symtab = NULL;  /*XXX*/
@@ -201,31 +203,45 @@
 
        dprintf(("%d relocs\n", trsz/12));
 
-       if (sumsize == 0) {
+       if (Sflag) {
                /*
-                * XXX overly cautious, but this guarantees that 16bit
-                * pc offsets and our relocs always work.
+                * For second-stage boot, there's no limit for binary size,
+                * and we dynamically scale it. However, it should be small
+                * enough so that
+                *
+                *  (1) all R_68K_PC16 symbols get relocated, and
+                *
+                *  (2) all values in our relocation table for R_68K_32
+                *      symbols fit within 16-bit integer.
+                *
+                * Both will be checked by codes below.
+                *
+                * At the moment, (2) is satisfied with sufficient margin.
+                * But if it is not the case in the future, format for
+                * relocation table should be modified.
                 */
-               bbsize = 32768;
-               if (bbsize < (tsz + dsz + bsz)) {
-                       errx(1, "%s: too big (%d < (%d + %d + %d))",
-                           argv[0], bbsize, tsz, dsz, bsz);
-               }
+               bbsize = roundup(tsz + dsz, 512);
                sumsize = bbsize / 512;
+       } else {
+               /*
+                * We have one contiguous area allocated by the ROM to us.
+                */
+               if (tsz + dsz + bsz > bbsize)
+                       errx(1, "%s: resulting image too big %d+%d+%d=%d",
+                           argv[0], tsz, dsz, bsz, tsz + dsz + bsz);
        }
 
-       buffer = malloc(bbsize);
-       relbuf = (u_int32_t *)malloc(bbsize);
+       buffer = NULL;
+       relbuf = NULL;
+
+retry:
+       pcrelsz = r32sz = 0;
+
+       buffer = realloc(buffer, bbsize);
+       relbuf = realloc(relbuf, bbsize);
        if (buffer == NULL || relbuf == NULL)
                err(1, "Unable to allocate memory\n");
 
-       /*
-        * We have one contiguous area allocated by the ROM to us.
-        */
-       if (tsz+dsz+bsz > bbsize)
-               errx(1, "%s: resulting image too big %d+%d+%d=%d", argv[0],
-                   tsz, dsz, bsz, tsz + dsz + bsz);
-
        memset(buffer, 0, bbsize);
 
        /* Allocate and load loadable sections */
@@ -363,7 +379,10 @@
                lptr = (u_int32_t *)&buffer[relbuf[i]];
                addrdiff = relbuf[i] - oldaddr;
                dprintf(("(0x%04x, 0x%04x): ", *lptr, addrdiff));
-               if (addrdiff > 255) {
+               if (addrdiff > 0xffff) {
+                       errx(1, "addrdiff overflows: relbuf = 0x%08x, "
+                           "oldaddr = 0x%08x, abort.\n", relbuf[i], oldaddr);
+               } else if (addrdiff > 0xff) {
                        *rpo = 0;
                        if (delta > 0) {
                                ++rpo;
@@ -387,8 +406,16 @@
                oldaddr = relbuf[i];
 
                if (delta < 0 ? rpo <= buffer+tsz+dsz
-                   : rpo >= buffer + bbsize)
-                       errx(1, "Relocs don't fit.");
+                   : rpo >= buffer + bbsize) {
+                       printf("relocs don't fit, ");
+                       if (Sflag) {
+                               printf("retry.\n");
+                               bbsize += 512;
+                               sumsize++;
+                               goto retry;
+                       } else
+                               errx(1, "abort.");
+               }
        }
        *rpo = 0; rpo += delta;
        *rpo = 0; rpo += delta;
@@ -401,8 +428,16 @@
         * RELOCs must fit into the bss area.
         */
        if (delta < 0 ? rpo <= buffer+tsz+dsz
-           : rpo >= buffer + bbsize)
-               errx(1, "Relocs don't fit.");
+           : rpo >= buffer + bbsize) {
+               printf("relocs don't fit, ");
+               if (Sflag) {
+                       printf("retry.\n");
+                       bbsize += 512;
+                       sumsize++;
+                       goto retry;
+               } else
+                       errx(1, "abort.");
+       }
 
        if (undefsyms > 0)
                errx(1, "Undefined symbols referenced");