I am trying to transfer a binary file over a serial port on a small embedded device that doesn't have uudecode, base64 or x/y/z/ modem utils.
What I tried for far is:
$ sudo picocom -l -r -b 921600 --send-cmd "ascii-xfr -snv" /dev/ttyS0
# cat > libdebug.so
$ cat libdebug.so | sudo tee /dev/ttyS0
But that hangs my device.
Actually, what I can do is upload my own uudecode.sh in ascii mode and then I can use it to decode my own binary file!
Here is the script that works on ksh:
#!/bin/ksh
# uudecode in POSIX bourne shell
#
# *EXCRUCIATINGLY* SLOW!!!
#
# Taken from a reply to a blog post here:
# http://www.weeklywhinge.com/?p=108
#
# Copyright (c) 2015, Rafael Kitover <rkitover@gmail.com>
# Modified in 2018, Philippe Bouchard <philippeb8@gmail.com>
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
bs=0
while read -r t ; do
if [ "$bs" -eq 1 ] ; then
if [ "a$t" = "aend" ] ; then
bs=2
else
set $(printf "%d " "'$(echo $t | cut -c1)" "'$(echo $t | cut -c2)" "'$(echo $t | cut -c3)" "'$(echo $t | cut -c4)" "'$(echo $t | cut -c5)" "'$(echo $t | cut -c6)" "'$(echo $t | cut -c7)" "'$(echo $t | cut -c8)" "'$(echo $t | cut -c9)" "'$(echo $t | cut -c10)" "'$(echo $t | cut -c11)" "'$(echo $t | cut -c12)" "'$(echo $t | cut -c13)" "'$(echo $t | cut -c14)" "'$(echo $t | cut -c15)" "'$(echo $t | cut -c16)" "'$(echo $t | cut -c17)" "'$(echo $t | cut -c18)" "'$(echo $t | cut -c19)" "'$(echo $t | cut -c20)" "'$(echo $t | cut -c21)" "'$(echo $t | cut -c22)" "'$(echo $t | cut -c23)" "'$(echo $t | cut -c24)" "'$(echo $t | cut -c25)" "'$(echo $t | cut -c26)" "'$(echo $t | cut -c27)" "'$(echo $t | cut -c28)" "'$(echo $t | cut -c29)" "'$(echo $t | cut -c30)" "'$(echo $t | cut -c31)" "'$(echo $t | cut -c32)" "'$(echo $t | cut -c33)" "'$(echo $t | cut -c34)" "'$(echo $t | cut -c35)" "'$(echo $t | cut -c36)" "'$(echo $t | cut -c37)" "'$(echo $t | cut -c38)" "'$(echo $t | cut -c39)" "'$(echo $t | cut -c40)" "'$(echo $t | cut -c41)" "'$(echo $t | cut -c42)" "'$(echo $t | cut -c43)" "'$(echo $t | cut -c44)" "'$(echo $t | cut -c45)" "'$(echo $t | cut -c46)" "'$(echo $t | cut -c47)" "'$(echo $t | cut -c48)" "'$(echo $t | cut -c49)" "'$(echo $t | cut -c50)" "'$(echo $t | cut -c51)" "'$(echo $t | cut -c52)" "'$(echo $t | cut -c53)" "'$(echo $t | cut -c54)" "'$(echo $t | cut -c55)" "'$(echo $t | cut -c56)" "'$(echo $t | cut -c57)" "'$(echo $t | cut -c58)" "'$(echo $t | cut -c59)" "'$(echo $t | cut -c60)" "'$(echo $t | cut -c61)")
l=$(($1 -32 & 63 ))
shift
while [ $l -gt 0 ] ; do
i0=$(($1 -32 & 63))
shift
i1=$(($1 -32 & 63))
shift
i2=$(($1 -32 & 63))
shift
i3=$(($1 -32 & 63))
shift
if [ $l -gt 2 ] ; then
echo -ne "\0$(($i0 >> 4))$(($i0 >> 1 & 7))$(($i0 << 2 & 4 | $i1 >> 4))\0$(($i1 >> 2 & 3))$(($i1 << 1 & 6 | $i2 >> 5))$(($i2 >> 2 & 7))\0$(($i2 & 3))$(($i3 >> 3 & 7))$(($i3 & 7))"
true
elif [ $l -eq 2 ] ; then
echo -ne "\0$(($i0 >> 4))$(($i0 >> 1 & 7))$(($i0 << 2 & 4 | $i1 >> 4))\0$(($i1 >> 2 & 3))$(($i1 << 1 & 6 | $i2 >> 5))$(($i2 >> 2 & 7))"
true
else
echo -ne "\0$(($i0 >> 4))$(($i0 >> 1 & 7))$(($i0 << 2 & 4 | $i1 >> 4))"
true
fi
l=$(($l-3))
done
fi
elif [ $(echo $t | cut -c1-5) = "begin" ]; then
bs=1
fi
done
Then it can be used as such on the device:
# uudecode.sh < libdebug.so.uu > libdebug.so
EDIT
Apparently "printf" is not even present on my device but not to worry since there's an even faster script available in awk:
#!/bin/sh
# uudecode in GNU awk (and some others, like OpenBSD) decodes stdin to stdout
#
# Copyright (c) 2014, Rafael Kitover <rkitover@gmail.com>
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
awk=awk
if command -v gawk >/dev/null; then
awk=gawk
fi
$awk '
BEGIN {
charset=" !\"#$%&'\''()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_";
}
function charval(char) {
return index(charset, char) + 32 - 1;
}
/^begin / { next }
/^end$/ { exit }
{
cnt = substr($0, 1, 1);
if (cnt == "`") next;
cnt = charval(cnt) - 32;
enc = substr($0, 2, length($0) - 1);
chars = 0;
pos = 1;
while (chars < cnt) {
grp = substr(enc, pos, 4);
gsub(/`/, " ", grp); # zero bytes
c1 = charval(substr(grp, 1, 1)) - 32;
c2 = charval(substr(grp, 2, 1)) - 32;
c3 = charval(substr(grp, 3, 1)) - 32;
c4 = charval(substr(grp, 4, 1)) - 32;
chars_bits = or(c4, or(or(lshift(c3, 6), lshift(c2, 12)), lshift(c1, 18)));
char[1] = sprintf("%c", rshift(and(chars_bits, 16711680), 16));
char[2] = sprintf("%c", rshift(and(chars_bits, 65280), 8));
char[3] = sprintf("%c", and(chars_bits, 255));
for (i = 1; i <= 3 && chars < cnt; i++) {
printf("%s", char[i]);
chars++;
}
pos += 4;
}
}
'