1 files changed, 39 insertions, 0 deletions
diff --git a/arch/x86/tools/calc_run_size.pl b/arch/x86/tools/calc_run_size.pl
new file mode 100644
index 000000000000..23210baade2d
--- /dev/null
+++ b/arch/x86/tools/calc_run_size.pl
@@ -0,0 +1,39 @@
+#!/usr/bin/perl
+#
+# Calculate the amount of space needed to run the kernel, including room for
+# the .bss and .brk sections.
+#
+# Usage:
+# objdump -h a.out | perl calc_run_size.pl
+use strict;
+
+my $mem_size = 0;
+my $file_offset = 0;
+
+my $sections=" *[0-9]+ \.(?:bss|brk) +";
+while (<>) {
+	if (/^$sections([0-9a-f]+) +(?:[0-9a-f]+ +){2}([0-9a-f]+)/) {
+		my $size = hex($1);
+		my $offset = hex($2);
+		$mem_size += $size;
+		if ($file_offset == 0) {
+			$file_offset = $offset;
+		} elsif ($file_offset != $offset) {
+			# BFD linker shows the same file offset in ELF.
+			# Gold linker shows them as consecutive.
+			next if ($file_offset + $mem_size == $offset + $size);
+
+			printf STDERR "file_offset: 0x%lx\n", $file_offset;
+			printf STDERR "mem_size: 0x%lx\n", $mem_size;
+			printf STDERR "offset: 0x%lx\n", $offset;
+			printf STDERR "size: 0x%lx\n", $size;
+
+			die ".bss and .brk are non-contiguous\n";
+		}
+	}
+}
+
+if ($file_offset == 0) {
+	die "Never found .bss or .brk file offset\n";
+}
+printf("%d\n", $mem_size + $file_offset);