Re: [Qemu-devel] [PATCH v2] signrom: Rewrite as python script

[Jan Kiszka]

On 2012-03-05 15:09, Jan Kiszka wrote:
> Now that we have a hard dependency on python anyway, we can replace the
> slow shell script to calculate the option ROM checksum with a fast AND
> portable python version. Tested both with python 2.7 and 3.1.
> 
> Signed-off-by: Jan Kiszka <address@hidden>
> ---
> 
> Changes in v2:
>  - Switch to GPLv2+.
>    The tool replaces an inefficient GPLv2+ implementation, so want to
>    avoid any license "regression". As it is self-contained, it doesn't
>    affect the QEMU core license anyway (which least common denominator
>    remains GPLv2).
> 

Ping?

>  pc-bios/optionrom/Makefile |    2 +-
>  scripts/signrom.py         |   40 +++++++++++++++++++++++++++++++++++++++
>  scripts/signrom.sh         |   45 
> --------------------------------------------
>  3 files changed, 41 insertions(+), 46 deletions(-)
>  create mode 100644 scripts/signrom.py
>  delete mode 100755 scripts/signrom.sh
> 
> diff --git a/pc-bios/optionrom/Makefile b/pc-bios/optionrom/Makefile
> index f6b4027..57d8bd0 100644
> --- a/pc-bios/optionrom/Makefile
> +++ b/pc-bios/optionrom/Makefile
> @@ -26,7 +26,7 @@ build-all: multiboot.bin linuxboot.bin kvmvapic.bin
>       $(call quiet-command,$(OBJCOPY) -O binary -j .text $< $@,"  Building 
> $(TARGET_DIR)$@")
>  
>  %.bin: %.raw
> -     $(call quiet-command,$(SHELL) $(SRC_PATH)/scripts/signrom.sh $< $@,"  
> Signing $(TARGET_DIR)$@")
> +     $(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/signrom.py $< $@,"  
> Signing $(TARGET_DIR)$@")
>  
>  clean:
>       rm -f *.o *.d *.raw *.img *.bin *~
> diff --git a/scripts/signrom.py b/scripts/signrom.py
> new file mode 100644
> index 0000000..f9c35cc
> --- /dev/null
> +++ b/scripts/signrom.py
> @@ -0,0 +1,40 @@
> +#
> +# Option ROM signing utility
> +#
> +# Authors:
> +#  Jan Kiszka <address@hidden>
> +#
> +# This work is licensed under the terms of the GNU GPL, version 2 or later.
> +# See the COPYING file in the top-level directory.
> +
> +import sys
> +import struct
> +
> +if len(sys.argv) < 3:
> +    print('usage: signrom.py input output')
> +    sys.exit(1)
> +
> +fin = open(sys.argv[1], 'rb')
> +fout = open(sys.argv[2], 'wb')
> +
> +fin.seek(2)
> +size = ord(fin.read(1)) * 512 - 1
> +
> +fin.seek(0)
> +data = fin.read(size)
> +fout.write(data)
> +
> +checksum = 0
> +for b in data:
> +    # catch Python 2 vs. 3 differences
> +    if isinstance(b, int):
> +        checksum += b
> +    else:
> +        checksum += ord(b)
> +checksum = (256 - checksum) % 256
> +
> +# Python 3 no longer allows chr(checksum)
> +fout.write(struct.pack('B', checksum))
> +
> +fin.close()
> +fout.close()
> diff --git a/scripts/signrom.sh b/scripts/signrom.sh
> deleted file mode 100755
> index 9dc5c63..0000000
> --- a/scripts/signrom.sh
> +++ /dev/null
> @@ -1,45 +0,0 @@
> -#!/bin/sh
> -
> -# Option ROM Signing utility
> -#
> -# This program is free software; you can redistribute it and/or modify
> -# it under the terms of the GNU General Public License as published by
> -# the Free Software Foundation; either version 2 of the License, or
> -# (at your option) any later version.
> -#
> -# This program is distributed in the hope that it will be useful,
> -# but WITHOUT ANY WARRANTY; without even the implied warranty of
> -# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> -# GNU General Public License for more details.
> -#
> -# You should have received a copy of the GNU General Public License
> -# along with this program; if not, see <http://www.gnu.org/licenses/>.
> -#
> -# Copyright Novell Inc, 2009
> -#   Authors: Alexander Graf <address@hidden>
> -#
> -# Syntax: signrom.sh <input> <output>
> -
> -# did we get proper arguments?
> -test "$1" -a "$2" || exit 1
> -
> -sum=0
> -
> -# find out the file size
> -x=`dd if="$1" bs=1 count=1 skip=2 2>/dev/null | od -t u1 -A n`
> -#size=`expr $x \* 512 - 1`
> -size=$(( $x * 512 - 1 ))
> -
> -# now get the checksum
> -nums=`od -A n -t u1 -v -N $size "$1"`
> -for i in ${nums}; do
> -    # add each byte's value to sum
> -    sum=`expr \( $sum + $i \) % 256`
> -done
> -
> -sum=$(( (256 - $sum) % 256 ))
> -sum_octal=$( printf "%o" $sum )
> -
> -# and write the output file
> -cp "$1" "$2"
> -printf "\\$sum_octal" | dd of="$2" bs=1 count=1 seek=$size conv=notrunc 
> 2>/dev/null

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