Changed the memory sizing code so that if the following conditions

are met:

1) The BIOS indicates that there is exactly 64MB of RAM, and
2) The memory size isn't specified with the MAXMEM option or
   the npx0 msize hack,

   ...then do a speculative memory probe beyond the 64MB's until the
first bad page is encountered. This is an admitted hack, but should
nonetheless deal with detecting the correct amount of memory in nearly
all of the modern systems with >64MB of RAM.
Also made a change that will cause the list of detected memory chunks
to be printed if bootverbose is set.

1 files changed, 35 insertions, 21 deletions

diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index ef25175..8172e72 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
- *	$Id: machdep.c,v 1.260 1997/09/01 01:54:50 bde Exp $
+ *	$Id: machdep.c,v 1.261 1997/09/02 20:05:28 bde Exp $
  */
 
 #include "apm.h"
@@ -174,7 +174,6 @@ SYSCTL_PROC(_hw, HW_USERMEM, usermem, CTLTYPE_INT|CTLFLAG_RD,
 	0, 0, sysctl_hw_usermem, "I", "");
 
 int boothowto = 0, bootverbose = 0, Maxmem = 0;
-static int	badpages = 0;
 long dumplo;
 extern int bootdev;
 
@@ -221,17 +220,11 @@ cpu_startup(dummy)
 	/*
 	 * Display any holes after the first chunk of extended memory.
 	 */
-	if (badpages != 0) {
-		int indx = 1;
+	if (bootverbose) {
+		int indx;
 
-		/*
-		 * XXX skip reporting ISA hole & unmanaged kernel memory
-		 */
-		if (phys_avail[0] == PAGE_SIZE)
-			indx += 2;
-
-		printf("Physical memory hole(s):\n");
-		for (; phys_avail[indx + 1] != 0; indx += 2) {
+		printf("Physical memory chunk(s):\n");
+		for (indx = 0; phys_avail[indx + 1] != 0; indx += 2) {
 			int size = phys_avail[indx + 1] - phys_avail[indx];
 
 			printf("0x%08lx - 0x%08lx, %d bytes (%d pages)\n", phys_avail[indx],
@@ -1075,9 +1068,10 @@ init386(first)
 	/* table descriptors - used to load tables by microp */
 	struct region_descriptor r_gdt, r_idt;
 #endif
-	int	pagesinbase, pagesinext;
-	int	target_page, pa_indx;
-	int	off;
+	int pagesinbase, pagesinext;
+	int target_page, pa_indx;
+	int off;
+	int speculative_mtest;
 
 	proc0.p_addr = proc0paddr;
 
@@ -1299,15 +1293,30 @@ init386(first)
 	 * called something like "Maxphyspage".
 	 */
 	Maxmem = pagesinext + 0x100000/PAGE_SIZE;
+	/*
+	 * Indicate that we wish to do a speculative search for memory beyond
+	 * the end of the reported size if the indicated amount is 64MB (0x4000
+	 * pages) - which is the largest amount that the BIOS/bootblocks can
+	 * currently report. If a specific amount of memory is indicated via
+	 * the MAXMEM option or the npx0 "msize", then don't do the speculative
+	 * memory test.
+	 */
+	if (Maxmem == 0x4000)
+		speculative_mtest = TRUE;
+	else
+		speculative_mtest = FALSE;
 
 #ifdef MAXMEM
 	Maxmem = MAXMEM/4;
+	speculative_mtest = FALSE;
 #endif
 
 #if NNPX > 0
 	idp = find_isadev(isa_devtab_null, &npxdriver, 0);
-	if (idp != NULL && idp->id_msize != 0)
+	if (idp != NULL && idp->id_msize != 0) {
 		Maxmem = idp->id_msize / 4;
+		speculative_mtest = FALSE;
+	}
 #endif
 
 #ifdef SMP
@@ -1327,7 +1336,6 @@ init386(first)
 	 * XXX  ...but we probably should.
 	 */
 	pa_indx = 0;
-	badpages = 0;
 	if (pagesinbase > 1) {
 		phys_avail[pa_indx++] = PAGE_SIZE;	/* skip first page of memory */
 		phys_avail[pa_indx] = ptoa(pagesinbase);/* memory up to the ISA hole */
@@ -1338,7 +1346,9 @@ init386(first)
 	}
 
 	for (target_page = avail_start; target_page < ptoa(Maxmem); target_page += PAGE_SIZE) {
-		int tmp, page_bad = FALSE;
+		int tmp, page_bad;
+
+		page_bad = FALSE;
 
 		/*
 		 * map page into kernel: valid, read/write, non-cacheable
@@ -1393,9 +1403,16 @@ init386(first)
 			 * the end pointer. Otherwise start a new chunk.
 			 * Note that "end" points one higher than end,
 			 * making the range >= start and < end.
+			 * If we're also doing a speculative memory
+			 * test and we at or past the end, bump up Maxmem
+			 * so that we keep going. The first bad page
+			 * will terminate the loop.
 			 */
 			if (phys_avail[pa_indx] == target_page) {
 				phys_avail[pa_indx] += PAGE_SIZE;
+				if (speculative_mtest == TRUE &&
+				    phys_avail[pa_indx] >= (64*1024*1024))
+					Maxmem++;
 			} else {
 				pa_indx++;
 				if (pa_indx == PHYS_AVAIL_ARRAY_END) {
@@ -1407,9 +1424,6 @@ init386(first)
 				phys_avail[pa_indx] = target_page + PAGE_SIZE;	/* end */
 			}
 			physmem++;
-		} else {
-			badpages++;
-			page_bad = FALSE;
 		}
 	}