18 Nov, 2010

1 commit

  • Before this commit, weak symbols were not overridden by non-weak symbols
    found in archive libraries when linking with recent versions of
    binutils. As stated in the System V ABI, "the link editor does not
    extract archive members to resolve undefined weak symbols".

    This commit changes all Makefiles to use partial linking (ld -r) instead
    of creating library archives, which forces all symbols to participate in
    linking, allowing non-weak symbols to override weak symbols as intended.
    This approach is also used by Linux, from which the gmake function
    cmd_link_o_target (defined in config.mk and used in all Makefiles) is
    inspired.

    The name of each former library archive is preserved except for
    extensions which change from ".a" to ".o". This commit updates
    references accordingly where needed, in particular in some linker
    scripts.

    This commit reveals board configurations that exclude some features but
    include source files that depend these disabled features in the build,
    resulting in undefined symbols. Known such cases include:
    - disabling CMD_NET but not CMD_NFS;
    - enabling CONFIG_OF_LIBFDT but not CONFIG_QE.

    Signed-off-by: Sebastien Carlier

    Sebastien Carlier
     

30 Oct, 2010

1 commit

  • By now, the majority of architectures have working relocation
    support, so the few remaining architectures have become exceptions.
    To make this more obvious, we make working relocation now the default
    case, and flag the remaining cases with CONFIG_NEEDS_MANUAL_RELOC.

    Signed-off-by: Wolfgang Denk
    Tested-by: Heiko Schocher
    Tested-by: Reinhard Meyer

    Wolfgang Denk
     

27 Oct, 2010

1 commit

  • CONFIG_SYS_GBL_DATA_SIZE has always been just a bad workarond for not
    being able to use "sizeof(struct global_data)" in assembler files.
    Recent experience has shown that manual synchronization is not
    reliable enough. This patch renames CONFIG_SYS_GBL_DATA_SIZE into
    GENERATED_GBL_DATA_SIZE which gets automatically generated by the
    asm-offsets tool. In the result, all definitions of this value can be
    deleted from the board config files. We have to make sure that all
    files that reference such data include the new file.

    No other changes have been done yet, but it is obvious that similar
    changes / simplifications can be done for other, related macro
    definitions as well.

    Signed-off-by: Wolfgang Denk
    Acked-by: Kumar Gala

    Wolfgang Denk
     

20 Oct, 2010

1 commit


20 Sep, 2010

5 commits

  • Portions of this work were supported by funding from
    the CE Linux Forum.

    Signed-off-by: Heiko Schocher

    Heiko Schocher
     
  • fixup_cmdtable() did all work for fixing up the cmdtable,
    if CONFIG_RELOC_FIXUP_WORKS is not defined.

    CONFIG_RELOC_FIXUP_WORKS is missing for i386! I talked
    with Graeme Russ, and he will fix this soon.

    Portions of this work were supported by funding from
    the CE Linux Forum.

    Signed-off-by: Heiko Schocher

    Heiko Schocher
     
  • bi_env is nowhere used, so delete it!

    Signed-off-by: Heiko Schocher

    similar patch posted from Dirk Behme Tue Jul 27 18:36:09 CEST 2010
    http://lists.denx.de/pipermail/u-boot/2010-July/074542.html

    Heiko Schocher
     
  • 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 ,
    Stefan Roese ,
    Heiko Schocher

    - Dropping forceenv() causes build problems on schmoogie

    => cc: Sergey Kubushyn

    - Build tested on PPC and ARM only; runtime tested with NOR and NAND
    flash only => needs testing!!

    Signed-off-by: Wolfgang Denk
    Cc: Matthias Fuchs ,
    Cc: Stefan Roese ,
    Cc: Heiko Schocher
    Cc: Sergey Kubushyn

    Wolfgang Denk
     
  • 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

    Wolfgang Denk
     

10 Aug, 2010

1 commit


04 Aug, 2010

1 commit

  • While running from flash, i. e. before relocation, we have only a
    limited C runtime environment without writable data segment. In this
    phase, some configurations (for example with environment in EEPROM)
    must not use the normal getenv(), but a special function. This
    function had been called getenv_r(), with the idea that the "_r"
    suffix would mean the same as in the _r_eentrant versions of some of
    the C library functions (for example getdate vs. getdate_r, getgrent
    vs. getgrent_r, etc.).

    Unfortunately this was a misleading name, as in U-Boot the "_r"
    generally means "running from RAM", i. e. _after_ relocation.

    To avoid confusion, rename into getenv_f() [as "running from flash"]

    Signed-off-by: Wolfgang Denk
    Acked-by: Detlev Zundel

    Wolfgang Denk
     

05 Jul, 2010

1 commit

  • 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
    Acked-by: Mike Frysinger

    Wolfgang Denk
     

13 Apr, 2010

3 commits