linux-sg2042/arch/x86/tools/calc_run_size.pl

40 lines
1.0 KiB
Perl

#!/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);