sysdump: dump CPUID informationsyslinux-3.85-pre7

Dump CPUID information in as generic of a way as is possible, given
the ugliness in certain places.

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

3 files changed, 115 insertions, 0 deletions

diff --git a/com32/sysdump/cpuid.c b/com32/sysdump/cpuid.c
new file mode 100644
index 00000000..40b20618
--- /dev/null
+++ b/com32/sysdump/cpuid.c
@@ -0,0 +1,112 @@
+/*
+ * Dump CPUID information
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <com32.h>
+#include <sys/cpu.h>
+#include "sysdump.h"
+#include "backend.h"
+
+struct cpuid_data {
+    uint32_t eax, ebx, ecx, edx;
+};
+
+struct cpuid_info {
+    uint32_t eax, ecx;
+    struct cpuid_data data;
+};
+
+static bool has_eflag(uint32_t flag)
+{
+	uint32_t f0, f1;
+
+	asm("pushfl ; "
+	    "pushfl ; "
+	    "popl %0 ; "
+	    "movl %0,%1 ; "
+	    "xorl %2,%1 ; "
+	    "pushl %1 ; "
+	    "popfl ; "
+	    "pushfl ; "
+	    "popl %1 ; "
+	    "popfl"
+	    : "=&r" (f0), "=&r" (f1)
+	    : "ri" (flag));
+
+	return !!((f0^f1) & flag);
+}
+
+static inline void get_cpuid(uint32_t eax, uint32_t ecx,
+			     struct cpuid_data *data)
+{
+    asm("cpuid"
+	: "=a" (data->eax), "=b" (data->ebx),
+	  "=c" (data->ecx), "=d" (data->edx)
+	: "a" (eax), "c" (ecx));
+}
+
+#define CPUID_CHUNK 128
+
+void dump_cpuid(struct backend *be)
+{
+    struct cpuid_info *buf = NULL;
+    int nentry, nalloc;
+    uint32_t region;
+    struct cpuid_data base_leaf;
+    uint32_t base, leaf, count;
+    struct cpuid_data invalid_leaf;
+    struct cpuid_data data;
+
+    if (!has_eflag(EFLAGS_ID))
+	return;
+
+    printf("Dumping CPUID... ");
+
+    nentry = nalloc = 0;
+
+    /* Find out what the CPU returns for invalid leaves */
+    get_cpuid(0, 0, &base_leaf);
+    get_cpuid(base_leaf.eax+1, 0, &invalid_leaf);
+
+    for (region = 0 ; region <= 0xffff ; region++) {
+	base = region << 16;
+
+	get_cpuid(base, 0, &base_leaf);
+	if (region && !memcmp(&base_leaf, &invalid_leaf, sizeof base_leaf))
+	    continue;
+
+	if ((base_leaf.eax ^ base) & 0xffff0000)
+	    continue;
+
+	for (leaf = base ; leaf <= base_leaf.eax ; leaf++) {
+	    get_cpuid(leaf, 0, &data);
+	    count = 0;
+
+	    do {
+		if (nentry >= nalloc) {
+		    nalloc += CPUID_CHUNK;
+		    buf = realloc(buf, nalloc*sizeof *buf);
+		    if (!buf)
+			return;		/* FAILED */
+		}
+		buf[nentry].eax = leaf;
+		buf[nentry].ecx = count;
+		buf[nentry].data = data;
+		nentry++;
+		count++;
+
+		get_cpuid(leaf, count, &data);
+	    } while (memcmp(&data, &buf[nentry-1].data, sizeof data) &&
+		     (data.eax | data.ebx | data.ecx | data.edx));
+	}
+    }
+
+    if (nentry)
+	cpio_writefile(be, "cpuid", buf, nentry*sizeof *buf);
+    free(buf);
+
+    printf("done.\n");
+}
diff --git a/com32/sysdump/main.c b/com32/sysdump/main.c
index fd3fc934..c231c29e 100644
--- a/com32/sysdump/main.c
+++ b/com32/sysdump/main.c
@@ -37,6 +37,7 @@ static void dump_all(struct backend *be, const char *argv[], size_t len)
     dump_memory_map(be);
     dump_memory(be);
     dump_dmi(be);
+    dump_cpuid(be);
     dump_pci(be);
     dump_vesa_tables(be);
 
diff --git a/com32/sysdump/sysdump.h b/com32/sysdump/sysdump.h
index f2c8f7a0..61a04a2b 100644
--- a/com32/sysdump/sysdump.h
+++ b/com32/sysdump/sysdump.h
@@ -4,8 +4,10 @@
 struct backend;
 
 void dump_memory_map(struct backend *);
+void snapshot_lowmem(void);
 void dump_memory(struct backend *);
 void dump_dmi(struct backend *);
+void dump_cpuid(struct backend *);
 void dump_pci(struct backend *);
 void dump_vesa_tables(struct backend *);