#!/bin/sh # Called from top-level directory a-la # # scripts/generate_BUFSIZ.sh include/common_bufsiz.h . ./.config || exit 1 debug=false #debug=true postcompile=false test x"$1" = x"--post" && { postcompile=true; shift; } common_bufsiz_h=$1 test x"$NM" = x"" && NM="${CONFIG_CROSS_COMPILER_PREFIX}nm" test x"$CC" = x"" && CC="${CONFIG_CROSS_COMPILER_PREFIX}gcc" exitcmd="exit 0" regenerate() { cat >"$1.$$" test -f "$1" && diff "$1.$$" "$1" >/dev/null && rm "$1.$$" && return mv "$1.$$" "$1" } generate_std_and_exit() { $debug && echo "Configuring: bb_common_bufsiz1[] in bss" { echo "enum { COMMON_BUFSIZE = 1024 };" echo "extern char bb_common_bufsiz1[];" echo "#define setup_common_bufsiz() ((void)0)" } | regenerate "$common_bufsiz_h" echo "std" >"$common_bufsiz_h.method" $exitcmd } generate_big_and_exit() { $debug && echo "Configuring: bb_common_bufsiz1[] in bss, COMMON_BUFSIZE = $1" { echo "enum { COMMON_BUFSIZE = $1 };" echo "extern char bb_common_bufsiz1[];" echo "#define setup_common_bufsiz() ((void)0)" } | regenerate "$common_bufsiz_h" echo "$2" >"$common_bufsiz_h.method" $exitcmd } generate_1k_and_exit() { generate_big_and_exit 1024 "1k" } round_down_COMMON_BUFSIZE() { COMMON_BUFSIZE=1024 test "$1" -le 32 && return COMMON_BUFSIZE=$(( ($1-32) & 0x0ffffff0 )) COMMON_BUFSIZE=$(( COMMON_BUFSIZE < 1024 ? 1024 : COMMON_BUFSIZE )) } # User does not want any funky stuff? test x"$CONFIG_FEATURE_USE_BSS_TAIL" = x"y" || generate_std_and_exit # The script is run two times: before compilation, when it needs to # (re)generate $common_bufsiz_h, and directly after successful build, # when it needs to assess whether the build is ok to use at all (not buggy), # and (re)generate $common_bufsiz_h for a future build. if $postcompile; then # Postcompile needs to create/delete OK/FAIL files test -f busybox_unstripped || exit 1 test -f "$common_bufsiz_h.method" || exit 1 # How the build was done? method=`cat -- "$common_bufsiz_h.method"` # Get _end address END=`$NM busybox_unstripped | grep ' . _end$'| cut -d' ' -f1` test x"$END" = x"" && generate_std_and_exit $debug && echo "END:0x$END $((0x$END))" END=$((0x$END)) # Get PAGE_SIZE { echo "#include <sys/user.h>" echo "#if defined(PAGE_SIZE) && PAGE_SIZE > 0" echo "char page_size[PAGE_SIZE];" echo "#endif" } >page_size_$$.c $CC -c "page_size_$$.c" || exit 1 PAGE_SIZE=`$NM --size-sort "page_size_$$.o" | cut -d' ' -f1` rm "page_size_$$.c" "page_size_$$.o" test x"$PAGE_SIZE" = x"" && exit 1 $debug && echo "PAGE_SIZE:0x$PAGE_SIZE $((0x$PAGE_SIZE))" PAGE_SIZE=$((0x$PAGE_SIZE)) test $PAGE_SIZE -lt 1024 && exit 1 # How much space between _end[] and next page? PAGE_MASK=$((PAGE_SIZE-1)) TAIL_SIZE=$(( (-END) & PAGE_MASK )) $debug && echo "TAIL_SIZE:$TAIL_SIZE bytes" if test x"$method" = x"1k"; then { echo $TAIL_SIZE md5sum <.config | cut -d' ' -f1 stat -c "%Y" .config } >"$common_bufsiz_h.1k.OK" round_down_COMMON_BUFSIZE $((1024 + TAIL_SIZE)) # emit message only if COMMON_BUFSIZE is indeed larger test $COMMON_BUFSIZE -gt 1024 \ && echo "Rerun make to use larger COMMON_BUFSIZE ($COMMON_BUFSIZE)" test $COMMON_BUFSIZE = 1024 && generate_1k_and_exit generate_big_and_exit $COMMON_BUFSIZE "big" fi fi # Based on past success/fail of 1k build, decide next build type if test -f "$common_bufsiz_h.1k.OK"; then # previous 1k build succeeded oldcfg=`tail -n2 -- "$common_bufsiz_h.1k.OK"` curcfg=`md5sum <.config | cut -d' ' -f1; stat -c "%Y" .config` # config did not change if test x"$oldcfg" = x"$curcfg"; then # Try bigger COMMON_BUFSIZE if possible TAIL_SIZE=`head -n1 -- "$common_bufsiz_h.1k.OK"` round_down_COMMON_BUFSIZE $((1024 + TAIL_SIZE)) test $COMMON_BUFSIZE = 1024 && generate_1k_and_exit generate_big_and_exit $COMMON_BUFSIZE "big" fi # config did change rm -rf -- "$common_bufsiz_h.1k.OK" fi # There was no 1k build yet. Try it. generate_1k_and_exit