1 files changed, 42 insertions, 0 deletions

diff --git a/arch/x86/tools/calc_run_size.sh b/arch/x86/tools/calc_run_size.sh
new file mode 100644
index 000000000000..1a4c17bb3910
--- /dev/null
+++ b/arch/x86/tools/calc_run_size.sh
@@ -0,0 +1,42 @@
+#!/bin/sh
+#
+# Calculate the amount of space needed to run the kernel, including room for
+# the .bss and .brk sections.
+#
+# Usage:
+# objdump -h a.out | sh calc_run_size.sh
+
+NUM='\([0-9a-fA-F]*[ \t]*\)'
+OUT=$(sed -n 's/^[ \t0-9]*.b[sr][sk][ \t]*'"$NUM$NUM$NUM$NUM"'.*/\1\4/p')
+if [ -z "$OUT" ] ; then
+        echo "Never found .bss or .brk file offset" >&2
+        exit 1
+fi
+
+OUT=$(echo ${OUT# })
+sizeA=$(printf "%d" 0x${OUT%% *})
+OUT=${OUT#* }
+offsetA=$(printf "%d" 0x${OUT%% *})
+OUT=${OUT#* }
+sizeB=$(printf "%d" 0x${OUT%% *})
+OUT=${OUT#* }
+offsetB=$(printf "%d" 0x${OUT%% *})
+
+run_size=$(( $offsetA + $sizeA + $sizeB ))
+
+# BFD linker shows the same file offset in ELF.
+if [ "$offsetA" -ne "$offsetB" ] ; then
+        # Gold linker shows them as consecutive.
+        endB=$(( $offsetB + $sizeB ))
+        if [ "$endB" != "$run_size" ] ; then
+                printf "sizeA: 0x%x\n" $sizeA >&2
+                printf "offsetA: 0x%x\n" $offsetA >&2
+                printf "sizeB: 0x%x\n" $sizeB >&2
+                printf "offsetB: 0x%x\n" $offsetB >&2
+                echo ".bss and .brk are non-contiguous" >&2
+                exit 1
+        fi
+fi
+
+printf "%d\n" $run_size
+exit 0