From a967cd4db2aff9c03adfead4b981a3659e75daf4 Mon Sep 17 00:00:00 2001
From: Warner Losh <imp@FreeBSD.org>
Date: Fri, 3 Feb 2023 08:39:06 -0700
Subject: [PATCH] kboot: Update amd64 to use enumerate_memory_arch()

Move memory enumeration to the enumerate_memory_arch(), tweak the code a
bit to make that fit into that framework.

Also fix a bug in the name of the end location. The old code never found
memory (though amd64 doesn't yet work, this lead to using fallback
addresses that were good enough for QEMU...).

Sponsored by:		Netflix
Reviewed by:		kevans
Differential Revision:	https://reviews.freebsd.org/D38250
---
 stand/kboot/arch/amd64/load_addr.c | 40 +++++++++++++++---------------
 1 file changed, 20 insertions(+), 20 deletions(-)

diff --git a/stand/kboot/arch/amd64/load_addr.c b/stand/kboot/arch/amd64/load_addr.c
index fccd17cf8d51..528b4dba6758 100644
--- a/stand/kboot/arch/amd64/load_addr.c
+++ b/stand/kboot/arch/amd64/load_addr.c
@@ -24,21 +24,16 @@
  */
 
 #include <sys/param.h>
-#include <sys/endian.h>
+#include <machine/pc/bios.h>
+#include <machine/metadata.h>
 
 #include "stand.h"
 #include "host_syscall.h"
 #include "kboot.h"
+#include "bootstrap.h"
 
 /* Refactor when we do arm64 */
 
-struct memory_segments
-{
-	uint64_t	start;
-	uint64_t	end;
-	uint64_t	type;
-};
-
 enum types {
 	system_ram = 1,
 	acpi_tables,
@@ -68,6 +63,9 @@ struct kv
 
 #define MEMMAP "/sys/firmware/memmap"
 
+static struct memory_segments segs[64];	/* make dynamic later */
+static int nr_seg;
+
 static bool
 str2type(struct kv *kv, const char *buf, uint64_t *value)
 {
@@ -82,19 +80,18 @@ str2type(struct kv *kv, const char *buf, uint64_t *value)
 	return false;
 }
 
-static int
-read_memmap(struct memory_segments *segs, int maxseg)
+bool
+enumerate_memory_arch(void)
 {
 	int n;
 	char name[MAXPATHLEN];
 	char buf[80];
 
-	n = 0;
-	do {
+	for (n = 0; n < nitems(segs); n++) {
 		snprintf(name, sizeof(name), "%s/%d/start", MEMMAP, n);
 		if (!file2u64(name, &segs[n].start))
 			break;
-		snprintf(name, sizeof(name), "%s/%d/length", MEMMAP, n);
+		snprintf(name, sizeof(name), "%s/%d/end", MEMMAP, n);
 		if (!file2u64(name, &segs[n].end))
 			break;
 		snprintf(name, sizeof(name), "%s/%d/type", MEMMAP, n);
@@ -102,10 +99,11 @@ read_memmap(struct memory_segments *segs, int maxseg)
 			break;
 		if (!str2type(str2type_kv, buf, &segs[n].type))
 			break;
-		n++;
-	} while (n < maxseg);
+	}
 
-	return n;
+	nr_seg = n;
+
+	return true;
 }
 
 #define BAD_SEG ~0ULL
@@ -118,6 +116,11 @@ find_ram(struct memory_segments *segs, int nr_seg, uint64_t minpa, uint64_t alig
 {
 	uint64_t start;
 
+	printf("minpa %#jx align %#jx sz %#jx maxpa %#jx\n",
+	    (uintmax_t)minpa,
+	    (uintmax_t)align,
+	    (uintmax_t)sz,
+	    (uintmax_t)maxpa);
 	/* XXX assume segs are sorted in numeric order -- assumed not ensured */
 	for (int i = 0; i < nr_seg; i++) {
 		if (segs[i].type != system_ram ||
@@ -143,20 +146,17 @@ uint64_t
 kboot_get_phys_load_segment(void)
 {
 	static uint64_t base_seg = BAD_SEG;
-	struct memory_segments segs[32];
-	int nr_seg;
 
 	if (base_seg != BAD_SEG)
 		return (base_seg);
 
-	nr_seg = read_memmap(segs, nitems(segs));
 	if (nr_seg > 0)
 		base_seg = find_ram(segs, nr_seg, 2ULL << 20, 2ULL << 20,
 		    64ULL << 20, 4ULL << 30);
 	if (base_seg == BAD_SEG) {
 		/* XXX Should fall back to using /proc/iomem maybe? */
 		/* XXX PUNT UNTIL I NEED SOMETHING BETTER */
-		base_seg = 42ULL * (1 << 20); /* Jam it in at the odd-ball address of 42MB so it stands out */
+		base_seg = 300ULL * (1 << 20);
 	}
 	return (base_seg);
 }