sh: alignment

V7 happens to word pack binaries so that the low bit of the first address
beyond the end of the program is clear. We don't. This causes sh to get
a bit upset 50% of the time you fiddle with it. Instead check the sbrk
value when we start up and sbrk ourselves a byte if needed.

The sh allocator providing it is started on an even address will stay even.

diff --git a/Applications/V7/cmd/sh/blok.c b/Applications/V7/cmd/sh/blok.c
index f1c3ec7..742e114 100644 (file)
--- a/Applications/V7/cmd/sh/blok.c
+++ b/Applications/V7/cmd/sh/blok.c
@@ -12,7 +12,6 @@
 
 #include       "defs.h"
 
-
 /*
  *     storage allocator
  *     (circular first fit strategy)
@@ -24,11 +23,13 @@
 POS brkincr = BRKINCR;
 BLKPTR blokp;                  /* current search pointer */
 BLKPTR bloktop;                        /* top of arena (last blok) */
-static void *end;              /* end of memory */
+static uint8_t *end;           /* end of memory */
 
 void blokinit(void)
 {
-        end = sbrk(0);         /* Find where space starts */
+        end = setbrk(0);       /* Find where space starts */
+        if (((uint8_t)end) & 1)
+                end = setbrk(1);       /* Align */
         bloktop = BLK(end);
 }
 
@@ -41,21 +42,16 @@ ADDRESS alloc(POS nbytes)
                register BLKPTR p = blokp;
                register BLKPTR q;
                do {
-                       if (!busy(p)
-                           ) {
-                               while (!busy(q = p->word)) {
+                       if (!busy(p)) {
+                               while (!busy(q = p->word))
                                        p->word = q->word;
-                               }
+
                                if (ADR(q) - ADR(p) >= rbytes) {
                                        blokp = BLK(ADR(p) + rbytes);
-                                       if (q > blokp) {
+                                       if (q > blokp)
                                                blokp->word = p->word;
-                                               ;
-                                       }
-                                       p->word =
-                                           BLK(Rcheat(blokp) | BUSY);
+                                       p->word = BLK(Rcheat(blokp) | BUSY);
                                        return (ADR(p + 1));
-                                       ;
                                };
                        }
                        q = p;
@@ -78,7 +74,6 @@ void addblok(POS reqd)
                stakbsy = blokstak;
                bloktop->word = BLK(Rcheat(rndstak) | BUSY);
                bloktop = BLK(rndstak);
-               ;
        }
        reqd += brkincr;
        reqd &= ~(brkincr - 1);