The hush shell dynamically allocates (and re-allocates) memory for the
argument strings in the "char *argv[]" argument vector passed to
commands. Any code that modifies these pointers will cause serious
corruption of the malloc data structures and crash U-Boot, so make
sure the compiler can check that no such modifications are being done
by changing the code into "char * const argv[]".
This modification is the result of debugging a strange crash caused
after adding a new command, which used the following argument
processing code which has been working perfectly fine in all Unix
systems since version 6 - but not so in U-Boot:
int main (int argc, char **argv)
{
while (--argc > 0 && **++argv == '-') {
/* ====> */ while (*++*argv) {
switch (**argv) {
case 'd':
debug++;
break;
...
default:
usage ();
}
}
}
...
}
The line marked "====>" will corrupt the malloc data structures and
usually cause U-Boot to crash when the next command gets executed by
the shell. With the modification, the compiler will prevent this with
an
error: increment of read-only location '*argv'
N.B.: The code above can be trivially rewritten like this:
while (--argc > 0 && **++argv == '-') {
char *arg = *argv;
while (*++arg) {
switch (*arg) {
...
Signed-off-by: Wolfgang Denk <wd@denx.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
The more standard 'source' command provides identical functionality to
the autoscr command.
Environment variable names/values on the MVBC_P, MVBML7, kmeter1,
mgcoge, and km8xx boards are updated to no longer refernce 'autoscr'.
The 'autoscript' and 'autoscript_uname' environment variables are
also removed.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Acked-by: Andre Schwarz <andre.schwarz@matrix-vision.de>
Acked-by: Heiko Schocher <hs@denx.de>
Many of the help messages were not really helpful; for example, many
commands that take no arguments would not print a correct synopsis
line, but "No additional help available." which is not exactly wrong,
but not helpful either.
Commit ``Make "usage" messages more helpful.'' changed this
partially. But it also became clear that lots of "Usage" and "Help"
messages (fields "usage" and "help" in struct cmd_tbl_s respective)
were actually redundant.
This patch cleans this up - for example:
Before:
=> help dtt
dtt - Digital Thermometer and Thermostat
Usage:
dtt - Read temperature from digital thermometer and thermostat.
After:
=> help dtt
dtt - Read temperature from Digital Thermometer and Thermostat
Usage:
dtt
Signed-off-by: Wolfgang Denk <wd@denx.de>
According to the doc/feature-removal-schedule.txt, the "autoscr"
command will be replaced by the "source" command in approximately 6
months from now.
This patch prepares this change and starts a 6 month transition
period as follows:
- The new "source" command has been added, which implements exactly
the same functionlaity as the old "autoscr" command before
- The old "autoscr" command name is kept as an alias for compatibility
- Command sequences, script files atc. have been adapted to use the
new "source" command
- Related environment variables ("autoscript", "autoscript_uname")
have *not* been adapted yet; these will be renamed resp. removed in
a separate patch when the support for the "autoscr" command get's
finally dropped.
Signed-off-by: Wolfgang Denk <wd@denx.de>
