--- eeprom/decode-dimms.orig	2024-11-13 19:00:52.000000000 +0200
+++ eeprom/decode-dimms	2024-11-13 19:37:51.930060000 +0200
@@ -46,7 +46,8 @@
 use File::Basename;
 use vars qw($opt_html $opt_bodyonly $opt_side_by_side $opt_merge
 	    $opt_igncheck $use_sysfs $use_hexdump $sbs_col_width
-	    @vendors %decode_callback @dimm $current %hexdump_cache);
+	    @vendors %decode_callback @dimm $current %hexdump_cache
+	    $opt_smbdev $use_smbdev);
 
 use constant LITTLEENDIAN	=> "little-endian";
 use constant BIGENDIAN		=> "big-endian";
@@ -498,6 +499,7 @@
 }
 
 $use_sysfs = -d '/sys/bus';
+$use_smbdev = '/dev/smb0';
 
 # We consider that no data was written to this area of the SPD EEPROM if
 # all bytes read 0x00 or all bytes read 0xff
@@ -2435,8 +2437,38 @@
 
 		return ($size, ($bytes->[0] < 64) ? 64 : $bytes->[0]);
 	}
+}
+
+sub freebsd_readbyte ($$) {
+	my ($offset, $dimm_i) = @_;
+
+	my $command = sprintf('/usr/sbin/smbmsg -f %s -s %#02x -c %d -i 1 -F %%02x 2>/dev/null',
+			      $use_smbdev, $dimm_i, $offset);
+	my $output = `$command`;
+	chomp($output);
+	my $byte = hex($output);
+	return $byte;
 }
 
+sub freebsd_readword ($$) {
+	my ($offset, $dimm_i) = @_;
+
+	my $command = sprintf('/usr/sbin/smbmsg -f %s -s %#02x -c %d -w -i 2 -F %%04x 2>/dev/null',
+			      $use_smbdev, $dimm_i, $offset);
+	my $output = `$command`;
+	chomp($output);
+	my $word = hex($output);
+	return $word;
+}
+
+sub freebsd_spa_n($) {
+	my $page = shift;
+
+	my $command = sprintf('/usr/sbin/smbmsg -f %s -s %#02x -o 0 >/dev/null 2>&1',
+			      $use_smbdev, 0x6c + 2 * $page);
+	`$command`;
+}
+
 # Read bytes from SPD-EEPROM
 # Note: offset must be a multiple of 16!
 sub readspd($$$)
@@ -2450,6 +2482,15 @@
 			$size = @bytes - $offset;
 		}
 		return @bytes[$offset..($offset + $size - 1)];
+	} elsif ($use_smbdev) {
+		for my $i (0 .. (($size - 1) / 2)) {
+			my $off = $offset + 2 * $i;
+
+			freebsd_spa_n($off / 256);
+			my $word = freebsd_readword($off % 256, $dimm_i);
+			push (@bytes, $word & 0xff);
+			push (@bytes, $word >> 8);
+ 		}
 	} elsif ($use_sysfs) {
 		# Kernel 2.6 with sysfs
 		sysopen(HANDLE, "$dimm_i/eeprom", O_RDONLY)
@@ -2529,7 +2570,7 @@
 # Parse command-line
 foreach (@ARGV) {
 	if ($_ eq '-h' || $_ eq '--help') {
-		print "Usage: $0 [-c] [-f [-b]] [-x|-X file [files..]]\n",
+		print "Usage: $0 [-c] [-f [-b]] [-d|-x|-X file [files..]]\n",
 			"       $0 -h\n\n",
 			"  -f, --format            Print nice html output\n",
 			"  -b, --bodyonly          Don't print html header\n",
@@ -2540,6 +2581,7 @@
 			"      --no-merge-cells    Don't merge neighbour cells with identical values\n",
 			"                          (side-by-side output only)\n",
 			"  -c, --checksum          Decode completely even if checksum fails\n",
+			"  -d,                     Read data from the device\n",
 			"  -x,                     Read data from hexdump files\n",
 			"  -X,                     Same as -x except treat multibyte hex\n",
 			"                          data as little endian\n",
@@ -2579,6 +2621,10 @@
 		$opt_igncheck = 1;
 		next;
 	}
+	if ($_ eq '-d') {
+		$opt_smbdev = 1;
+		next;
+	}
 	if ($_ eq '-x') {
 		$use_hexdump = BIGENDIAN;
 		next;
@@ -2593,7 +2639,11 @@
 		exit;
 	}
 
-	push @dimm, { eeprom => basename($_), file => $_ } if $use_hexdump;
+	if ($opt_smbdev) {
+		$use_smbdev = $_;
+	} else {
+		push @dimm, { eeprom => basename($_), file => $_ } if $use_hexdump;
+	}
 }
 
 # Default values
@@ -2623,6 +2673,22 @@
 		@drivers = ('eeprom',
 			    'at24',
 			    'ee1004');	# DDR4
+	} elsif ($use_smbdev) {
+		my @dimms;
+
+		if (! -c $use_smbdev) {
+			print STDERR "SMBus device not found\n";
+			exit;
+		}
+		for my $spd (0xA0 .. 0xAE) {
+			next if ($spd % 2 != 0);
+			my @test_bytes = readspd(0, 4, $spd);
+			next unless spd_written(@test_bytes);
+			push @dimms, { eeprom => sprintf('0x%02X', $spd),
+				       file => $spd,
+				       driver => "smbus" };
+		}
+		return @dimms;
 	} else {
 		@drivers = ('eeprom');
 		$dir = '/proc/sys/dev/sensors';
@@ -2910,7 +2976,7 @@
 	if ($opt_side_by_side) {
 		print "\n\n";
 	} else {
-		printl2("\n\nDecoding EEPROM", $dimm[$current]->{file},
+		printl2("\n\nDecoding EEPROM", $dimm[$current]->{eeprom},
 			"text-decoration: underline; font-weight: bold;");
 	}
 	print "<table border=\"1\">\n" if $opt_html;