4 Commits (1724fe9adfed43c92605b139d4a71f2f4a52c734)

Author	SHA1	Message	Date
Wolfgang Denk	ea882baf9c	New implementation for internal handling of environment variables. ... Motivation: * Old environment code used a pessimizing implementation: - variable lookup used linear search => slow - changed/added variables were added at the end, i. e. most frequently used variables had the slowest access times => slow - each setenv() would calculate the CRC32 checksum over the whole environment block => slow * "redundant" envrionment was locked down to two copies * No easy way to implement features like "reset to factory defaults", or to select one out of several pre-defined (previously saved) sets of environment settings ("profiles") * No easy way to import or export environment settings ====================================================================== API Changes: - Variable names starting with '#' are no longer allowed I didn't find any such variable names being used; it is highly recommended to follow standard conventions and start variable names with an alphanumeric character - "printenv" will now print a backslash at the end of all but the last lines of a multi-line variable value. Multi-line variables have never been formally defined, allthough there is no reason not to use them. Now we define rules how to deal with them, allowing for import and export. - Function forceenv() and the related code in saveenv() was removed. At the moment this is causing build problems for the only user of this code (schmoogie - which has no entry in MAINTAINERS); may be fixed later by implementing the "env set -f" feature. Inconsistencies: - "printenv" will '\\'-escape the '\n' in multi-line variables, while "printenv var" will not do that. ====================================================================== Advantages: - "printenv" output much better readable (sorted) - faster! - extendable (additional variable properties can be added) - new, powerful features like "factory reset" or easy switching between several different environment settings ("profiles") Disadvantages: - Image size grows by typically 5...7 KiB (might shrink a bit again on systems with redundant environment with a following patch series) ====================================================================== Implemented: - env command with subcommands: - env print [arg ...] same as "printenv": print environment - env set [-f] name [arg ...] same as "setenv": set (and delete) environment variables ["-f" - force setting even for read-only variables - not implemented yet.] - end delete [-f] name not implemented yet ["-f" - force delete even for read-only variables] - env save same as "saveenv": save environment - env export [-t | -b | -c] addr [size] export internal representation (hash table) in formats usable for persistent storage or processing: -t: export as text format; if size is given, data will be padded with '\0' bytes; if not, one terminating '\0' will be added (which is included in the "filesize" setting so you can for exmple copy this to flash and keep the termination). -b: export as binary format (name=value pairs separated by '\0', list end marked by double "\0\0") -c: export as checksum protected environment format as used for example by "saveenv" command addr: memory address where environment gets stored size: size of output buffer With "-c" and size is NOT given, then the export command will format the data as currently used for the persistent storage, i. e. it will use CONFIG_ENV_SECT_SIZE as output block size and prepend a valid CRC32 checksum and, in case of resundant environment, a "current" redundancy flag. If size is given, this value will be used instead of CONFIG_ENV_SECT_SIZE; again, CRC32 checksum and redundancy flag will be inserted. With "-b" and "-t", always only the real data (including a terminating '\0' byte) will be written; here the optional size argument will be used to make sure not to overflow the user provided buffer; the command will abort if the size is not sufficient. Any remainign space will be '\0' padded. On successful return, the variable "filesize" will be set. Note that filesize includes the trailing/terminating '\0' byte(s). Usage szenario: create a text snapshot/backup of the current settings: => env export -t 100000 => era ${backup_addr} +${filesize} => cp.b 100000 ${backup_addr} ${filesize} Re-import this snapshot, deleting all other settings: => env import -d -t ${backup_addr} - env import [-d] [-t | -b | -c] addr [size] import external format (text or binary) into hash table, optionally deleting existing values: -d: delete existing environment before importing; otherwise overwrite / append to existion definitions -t: assume text format; either "size" must be given or the text data must be '\0' terminated -b: assume binary format ('\0' separated, "\0\0" terminated) -c: assume checksum protected environment format addr: memory address to read from size: length of input data; if missing, proper '\0' termination is mandatory - env default -f reset default environment: drop all environment settings and load default environment - env ask name [message] [size] same as "askenv": ask for environment variable - env edit name same as "editenv": edit environment variable - env run same as "run": run commands in an environment variable ====================================================================== TODO: - drop default env as implemented now; provide a text file based initialization instead (eventually using several text files to incrementally build it from common blocks) and a tool to convert it into a binary blob / object file. - It would be nice if we could add wildcard support for environment variables; this is needed for variable name auto-completion, but it would also be nice to be able to say "printenv ip*" or "printenv *addr*" - Some boards don't link any more due to the grown code size: DU405, canyonlands, sequoia, socrates. => cc: Matthias Fuchs <matthias.fuchs@esd-electronics.com>, Stefan Roese <sr@denx.de>, Heiko Schocher <hs@denx.de> - Dropping forceenv() causes build problems on schmoogie => cc: Sergey Kubushyn <ksi@koi8.net> - Build tested on PPC and ARM only; runtime tested with NOR and NAND flash only => needs testing!! Signed-off-by: Wolfgang Denk <wd@denx.de> Cc: Matthias Fuchs <matthias.fuchs@esd-electronics.com>, Cc: Stefan Roese <sr@denx.de>, Cc: Heiko Schocher <hs@denx.de> Cc: Sergey Kubushyn <ksi@koi8.net>	14 years ago
Wolfgang Denk	91a76751a0	Make getenv() work before relocation. ... So far, getenv() would work before relocation is most cases, even though it was not intended to be used that way. When switching to a hash table based implementation, this would break a number of boards. For convenience, we make getenv() check if it's running before relocation and, if so, use getenv_f() internally. Note that this is limited to simple cases, as we use a small static buffer (32 bytes) in the global data for this purpose. For this reason, it is also not a good idea to convert all current uses of getenv_f() into getenv() - some of the existing use cases need to be able to deal with longer variable values, so getenv_f() is still needed and recommended for use before relocation. Signed-off-by: Wolfgang Denk <wd@denx.de>	14 years ago
Wolfgang Denk	54841ab50c	Make sure that argv[] argument pointers are not modified. ... 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>	14 years ago
Peter Tyser	819833af39	Move architecture-specific includes to arch/$ARCH/include/asm ... This helps to clean up the include/ directory so that it only contains non-architecture-specific headers and also matches Linux's directory layout which many U-Boot developers are already familiar with. Signed-off-by: Peter Tyser <ptyser@xes-inc.com>	14 years ago