meminfo: update to deal with ACPI 3 and other braindamage

Add support for ACPI 3 and certain broken e820 implementations in the
meminfo program.  Some e820 implementations expect the buffer to
remain the same between different invocations, despite the fact that
there is absolutely no guarantee to that effect in the spec.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

diff --git a/com32/modules/meminfo.c b/com32/modules/meminfo.c
index 81678c5..4f2b372 100644 (file)
--- a/com32/modules/meminfo.c
+++ b/com32/modules/meminfo.c
@@ -25,6 +25,7 @@ struct e820_data {
   uint64_t base;
   uint64_t len;
   uint32_t type;
+  uint32_t extattr;
 } __attribute__((packed));
 
 static const char * const e820_types[] = {
@@ -32,6 +33,7 @@ static const char * const e820_types[] = {
   "reserved",
   "ACPI reclaim",
   "ACPI NVS",
+  "unusable",
 };
 
 static void dump_e820(void)
@@ -48,17 +50,26 @@ static void dump_e820(void)
   ireg.edi.w[0] = OFFS(__com32.cs_bounce);
   ireg.es       = SEG(__com32.cs_bounce);
 
+  memset(&ed, 0, sizeof ed);
+  ed.extattr = 1;
+
   do {
+    memcpy(__com32.cs_bounce, &ed, sizeof ed);
+
     __intcall(0x15, &ireg, &oreg);
     if (oreg.eflags.l & EFLAGS_CF ||
-       oreg.eax.l != 0x534d4150)
+       oreg.eax.l != 0x534d4150 ||
+       oreg.ecx.l < 20)
       break;
 
     memcpy(&ed, __com32.cs_bounce, sizeof ed);
 
+    if (oreg.ecx.l < 24)
+      ed.extattr = 1;
+
     /* ebx base length end type */
-    printf("%8x %016llx %016llx %016llx %x",
-          ireg.ebx.l, ed.base, ed.len, ed.base+ed.len, ed.type);
+    printf("%8x %016llx %016llx %016llx %d [%x]",
+          ireg.ebx.l, ed.base, ed.len, ed.base+ed.len, ed.type, ed.extattr);
 
     type = ed.type - 1;
     if (type < sizeof(e820_types)/sizeof(e820_types[0]))