arch/x86/tools/calc_run_size.sh

   1 #!/bin/sh
   2 #
   3 # Calculate the amount of space needed to run the kernel, including room for
   4 # the .bss and .brk sections.
   5 #
   6 # Usage:
   7 # objdump -h a.out | sh calc_run_size.sh
   8
   9 NUM='\([0-9a-fA-F]*[ \t]*\)'
  10 OUT=$(sed -n 's/^[ \t0-9]*.b[sr][sk][ \t]*'"$NUM$NUM$NUM$NUM"'.*/\1\4/p')
  11 if [ -z "$OUT" ] ; then
  12         echo "Never found .bss or .brk file offset" >&2
  13         exit 1
  14 fi
  15
  16 OUT=$(echo ${OUT# })
  17 sizeA=$(printf "%d" 0x${OUT%% *})
  18 OUT=${OUT#* }
  19 offsetA=$(printf "%d" 0x${OUT%% *})
  20 OUT=${OUT#* }
  21 sizeB=$(printf "%d" 0x${OUT%% *})
  22 OUT=${OUT#* }
  23 offsetB=$(printf "%d" 0x${OUT%% *})
  24
  25 run_size=$(( $offsetA + $sizeA + $sizeB ))
  26
  27 # BFD linker shows the same file offset in ELF.
  28 if [ "$offsetA" -ne "$offsetB" ] ; then
  29         # Gold linker shows them as consecutive.
  30         endB=$(( $offsetB + $sizeB ))
  31         if [ "$endB" != "$run_size" ] ; then
  32                 printf "sizeA: 0x%x\n" $sizeA >&2
  33                 printf "offsetA: 0x%x\n" $offsetA >&2
  34                 printf "sizeB: 0x%x\n" $sizeB >&2
  35                 printf "offsetB: 0x%x\n" $offsetB >&2
  36                 echo ".bss and .brk are non-contiguous" >&2
  37                 exit 1
  38         fi
  39 fi
  40
  41 printf "%d\n" $run_size
  42 exit 0