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>
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>
Commit 077e1958ca broke the ability of the
x86 port to boot from a cold-reset by removing the initial IDT. Re-
instate the initial IDT to allow cold-booting of x86 boards
Commit 54841ab50c made the argv parameter
to do_go_exec() const but did not allow for the fact that argv[-1] is
set to point to the global data structure and relies on argv being non-
const.
With this patch, do_go_exec() creates a new copy of the argv array with
an extra element to store global data pointer rather than simply
clobbering an arbitrary memory location.
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 <wd@denx.de>
Acked-by: Detlev Zundel <dzu@denx.de>
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>
AMD recently changed the licensing of the RAM sizing code to the
GPLv2 (or at your option any later version)
Signed-off-by: Graeme Russ <graeme.russ@gmail.com>
If the board has a high precision mico-second timer, it maked sense to use
it instead of the on-chip one
Signed-off-by: Graeme Russ <graeme.russ@gmail.com>
Add support for newer (up to 2.6.33) kernels
Add zboot command which takes the address of a bzImage as its first
argument and (optionally) the size of the bzImage as the second argument
(the second argument is needed for older kernels which do not include
the bzImage size in the header)
Signed-off-by: Graeme Russ <graeme.russ@gmail.com>
It is possibly to setup x86 boards to use non-PC/AT configurations. For
example, the sc520 is an x86 CPU with PC/AT and non-PC/AT peripherals.
This function allows the board to set itself up for maximum PC/AT
compatibility just before booting the Linux kernel (the Linux kernel
'just works' if everything is PC/AT compliant)
Signed-off-by: Graeme Russ <graeme.russ@gmail.com>
Currently, the GDT is either located in FLASH or in the non-relocated
U-Boot image in RAM. Both of these locations are unsafe as those
locations can be erased during a U-Boot update. Move the GDT into the
highest available memory location and relocate U-Boot to just below it
Signed-off-by: Graeme Russ <graeme.russ@gmail.com>
Add a parameter to the 32-bit entry to indicate if entry is from Real
Mode or not. If entry is from Real Mode, execute the destructive 'sizer'
routine to determine memory size as we are booting cold and running in
Flash. If not entering from Real Mode, we are executing a U-Boot image
from RAM and therefore the memory size is already known (and running
'sizer' will destroy the running image)
There are now two 32-bit entry points. The first is the 'in RAM' entry
point which exists at the start of the U-Boot binary image. As such,
you can load u-boot.bin in RAM and jump directly to the load address
without needing to calculate any offsets. The second entry point is
used by the real-to-protected mode switch
This patch also changes TEXT_BASE to 0x6000000 (in RAM). You can load
the resulting image at 0x6000000 and simple go 0x6000000 from the u-boot
prompt
Hopefully a later patch will completely elliminate any dependency on
TEXT_BASE like a relocatable linux kernel (perfect world)
Signed-off-by: Graeme Russ <graeme.russ@gmail.com>
This patch allows the low-level assembler boot-strap to obtain the RAM
size without calling the destructive 'sizer' routine. This allows
boot-strapping from a U-Boot image loaded in RAM
Signed-off-by: Graeme Russ <graeme.russ@gmail.com>
There is an error in how the assembler version of the sc520 memory size
reporting code works. As a result, it will only ever report at most the
size of one bank of RAM
Signed-off-by: Graeme Russ <graeme.russ@gmail.com>
Shamelessly steal the Linux x86 crash handling code and shove it into
U-Boot (cool - it fits). Be sure to include suitable attribution to
Linus
Signed-off-by: Graeme Russ <graeme.russ@gmail.com>
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>
Also move lib_$ARCH/config.mk to arch/$ARCH/config.mk
This change is intended to clean up the top-level directory structure
and more closely mimic Linux's directory organization.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Wolfgang Denk
Graeme Russ
Peter Tyser