Changes in the environment library are difficult to tracked by programs
using the library. Add simply an API version number that must be
increased each time when the API is changed.
This can be detected and a program can work with different versions of
the library.
Signed-off-by: Stefano Babic <sbabic@denx.de>
Move U-Boot private data into a separate file. This
lets export fw_env.h to be used by external programs
that want to change the environment using the library
built in tools/env.
Signed-off-by: Stefano Babic <sbabic@denx.de>
aes.h is a too generic name if this file can
be exported and used by a program.
Rename it to avoid any conflicts with
other files (for example, from openSSL).
Signed-off-by: Stefano Babic <sbabic@denx.de>
Richard reported U-Boot tools issues in OpenEmbedded/Yocto project.
OE needs to be able to change the default compiler. If we pass in
HOSTCC through the make command, it overwrites all HOSTCC instances,
including ones in tools/Makefile and tools/env/Makefile, which breaks
"make cross_tools" and "make env", respectively.
Add "override" directives to avoid overriding HOSTCC instances that
really need to point to the cross-compiler.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reported-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
commit 183923d3e4 enforces that the
environment must start at an erase block boundary.
For block devices the sample fw_env.config does not mandate a erase block size
for block devices. A missing setting defaults to the full env size.
Depending on the environment location the alignment check now errors out for
perfectly legal settings.
Fix this by defaulting to the standard blocksize of 0x200 for environments
stored in a block device.
That keeps the fw_env.config files for block devices working even with that
new check.
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
The default lockname is set to /var/lock. This limits the
usage of this application where OS uses different lockfile
location parameter.
For example, In case of android, the default lock
path location is /data.
Hence by providing the command line option to input lockfile
path will be useful to reuse the tool across multiple
operating system.
usage: ./fw_printenv -l <lockfile path>
Signed-off-by: Ravi Babu <ravibabu@ti.com>
This allows to take advantage of the environment being block aligned.
This is not a new constraint. Writes always start at the begin of the
environment, since the header with CRC/length as there.
Every environment modification requires updating the header
Signed-off-by: Andreas Fenkart <andreas.fenkart@digitalstrom.com>
flash_write_buf already looks up size/offset/#sector from struct
envdev_s. It can look up mtd_type as well. Same applies to
flash_read_buf. Makes the interface simpler
Signed-off-by: Andreas Fenkart <andreas.fenkart@digitalstrom.com>
the offset is not modified by linux ioctl call
see mtd_ioctl{drivers/mtd/mtdchar.c}
Makes the interface less ambiguous, since the caller can
now exclude a modification of blockstart
Signed-off-by: Andreas Fenkart <andreas.fenkart@digitalstrom.com>
instead of adhoc computation of the environment end,
use a function with a proper name
Signed-off-by: Andreas Fenkart <andreas.fenkart@digitalstrom.com>
addon 183923d3e
MMC/SATA have no erase blocks, only blocks. Hence the warning
about erase block alignment might be confusing in such environment.
Signed-off-by: Andreas Fenkart <andreas.fenkart@digitalstrom.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
For double buffering to work, the target buffer must always be big
enough to hold all data. This can only be ensured if buffers are of
equal size, otherwise one must be smaller and we risk data loss
when copying from the bigger to the smaller buffer.
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Andreas Fenkart <andreas.fenkart@digitalstrom.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
56086921 added support for unaligned environments access.
U-boot itself does not support this:
- env_nand.c fails when using an unaligned offset. It produces an
error in nand_erase_opts{drivers/mtd/nand/nand_util.c}
- in env_sf/env_flash the unused space at the end is preserved, but
not in the beginning. block alignment is assumed
- env_sata/env_mmc aligns offset/length to the block size of the
underlying device. data is silently redirected to the beginning of
a block
There is seems no use case for unaligned environment. If there is
some useful data at the beginning of the the block (e.g. end of u-boot)
that would be very unsafe. If the redundant environments are hosted by
the same erase block then that invalidates the idea of double buffering.
It might be that unaligned access was allowed in the past, and that
people with legacy u-boot are trapped. But at the time of 56086921
it wasn't supported and due to reasons above I guess it was never
introduced.
I prefer to remove that (unused) feature in favor of simplicity
Signed-off-by: Andreas Fenkart <andreas.fenkart@digitalstrom.com>
Acked-by: Stefan Agner <stefan.agner@toradex.com>
Format warnings (-Wformat) were shown in printf() calls after defining
DEBUG macro.
Update format string and explicitly cast variables to suppress all
warnings.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Try to avoid adhoc iteration of the environment. Reuse fw_getenv
to find the variables that should be printed. Only use open-coded
iteration when printing all variables.
For backwards compatibility, keep emitting a newline when
printing with value_only.
Signed-off-by: Andreas Fenkart <andreas.fenkart@digitalstrom.com>
forward declaration not needed when re-ordered
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Andreas Fenkart <andreas.fenkart@digitalstrom.com>
there are two groups of functions:
- application ready tools: fw_setenv/fw_getenv/fw_parse_script
these are used, when creating a single binary containing multiple
tools (busybox like)
- file access like: open/read/write/close
above functions are implemented on top of these. applications
can use those to modify several variables without creating a
temporary batch script file
tested with "./scripts/kernel-doc -html -v tools/env/fw_env.h"
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Andreas Fenkart <andreas.fenkart@digitalstrom.com>
A negative value for the offset is treated as a backwards offset for
from the end of the device/partition for block devices. This aligns
the behavior of the config file with the syntax of CONFIG_ENV_OFFSET
where the functionality has been introduced with
commit 5c088ee841 ("env_mmc: allow negative CONFIG_ENV_OFFSET").
Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Currently flash_read completes a crucial part of the environment
device configuration, the device type (mtd_type). This is rather
confusing as flash_io calls flash_read conditionally, and one might
think flash_write, which also makes use of mtd_type, gets called
before flash_read. But since flash_io is always called with O_RDONLY
first, this is not actually the case in reality.
However, it is much cleaner to complete and verify the config early
in parse_config. This also prepares the code for further extension.
Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Reviewed-by: Andreas Fenkart
If users of the library are happy with the default, e.g. config file
name. They can pass NULL as the opts pointer. This simplifies the
transition of existing library users.
FIXES a compile error. since common_args has been removed by
a previous patch
Signed-off-by: Andreas Fenkart <andreas.fenkart@digitalstrom.com>
checkpatch complains about in succeding patch. Prefer to fix all
declarations in a dedicated patch.
Signed-off-by: Andreas Fenkart <andreas.fenkart@digitalstrom.com>
env library is broken as the config file pointer is only initialized
in main(). When running in the env library parse_config() fails:
Cannot parse config file '(null)': Bad address
Ensure that config file pointer is always initialized.
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
fw_senten/fw_printenv can be compiled as a tools library,
excluding the fw_env_main object.
Reported-by: Stefano Babic <sbabic@denx.de>
Signed-off-by: Andreas Fenkart <andreas.fenkart@digitalstrom.com>
disabled original parsing, but not yet removed since the
argument indexing needs to be fixed
Signed-off-by: Andreas Fenkart <andreas.fenkart@digitalstrom.com>
goal is to use getopt for all argument parsing instead of adhoc
parsing in fw_getenv/fw_setenv functions
Signed-off-by: Andreas Fenkart <andreas.fenkart@digitalstrom.com>
With gcc 5.2 and later we get a bunch of "error: unknown type name" for
'uint8_t', 'uint32_t' and friends.
Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Sometimes it can be useful to link the fw_ tools instead
of having the fw_setenv/fw_printenv installed.
Patch exports the tool as library and allowes to link it
with own programs.
Signed-off-by: Stefano Babic <sbabic@denx.de>
CC: Tom Rini <trini@konsulko.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
When for example generating/manipulating SD card/eMMC images which
contain U-Boot and its environment(s), it is handy to use a given
configuration file instead of the compiled-in default one.
And since the default configuration file is expected under /etc
it's hard for an usual linux user account without special permissions
to use fw_printenv/fw_setenv for this purpose.
So allow to pass an optional filename via a new '-c' command
line argument.
Example:
$ ln -s fw_printenv tools/env/fw_setenv
$ cat fw_env.config
test.img 0x20000 0x20000
test.img 0x40000 0x20000
$ tools/env/fw_printenv -c ./fw_env.config fdt_file
fdt_file=imx28-duckbill.dtb
$ tools/env/fw_setenv -c ./fw_env.config fdt_file imx28-duckbill-spi.dtb
$ tools/env/fw_printenv -c ./fw_env.config fdt_file
fdt_file=imx28-duckbill-spi.dtb
Signed-off-by: Michael Heimpold <mhei@heimpold.de>
When building tools-only (or env) we need to be sure that we do use
<linux/kconfig.h> and do not use <generated/autoconf.h>. This will fix
problems such as running 'make defconfig' or 'make sandbox_config' and
then 'make tools-only'.
Based on the responses below to the thread add linux/kconfig.h higher in
the includes and drop the now unneeded autoconf.h lower down to ensure
the default environment is included correctly
http://lists.denx.de/pipermail/u-boot/2015-June/216849.html
Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
This patch fixes cross-compiling U-Boot tools with the musl C library:
* including <sys/types.h> is needed for ulong
* defining _GNU_SOURCE is needed for loff_t
Tested for target at91sam9261ek_dataflash_cs3.
Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>
Cc: Tom Rini <trini@konsulko.com>
Without this, when CONFIG_ENV_VARS_UBOOT_CONFIG is active we get
a compile time error when doing 'make env'.
In file included from tools/env/fw_env.c:117:0:
include/env_default.h:110:11: error: expected ‘}’ before ‘CONFIG_SYS_ARCH’
When building U-Boot this is included indirectly by the compiler switch
-include
/home/trdx/git.toradex.com/u-boot-2014.10-toradex/include/linux/kconfig.h
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
For example on a raspberry pi the u-boot environment can be
saved in a file on the first VFAT partition.
This example illustrates how to use it with fw_printenv/fw_setenv.
Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
On architectures where 'long' is 64 bit, the u-boot environment
as seen by the fw_env tools was missing 4 bytes.
This patch fixes getenvsize(), and thus also ensures that the
environment's CRC32 checksum is calculated correctly.
Signed-off-by: Dominic Sacré <dominic.sacre@gmx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Tom Rini <trini@ti.com>
When building the U-Boot tools for non-ELF platforms (such as Blackfin
FLAT), since commit 79fc0c5f49
("tools/env: cross-compile fw_printenv without setting HOSTCC"), the
build fails because it tries to strip a FLAT binary, which does not
make sense.
This commit solves this by changing the stripping logic in
tools/env/Makefile to be similar to the one in tools/Makefile. This
logic continues to apply strip to the final binary, but does not abort
the build if it fails, and does the stripping in place on the final
binary. This allows the logic to work fine if stripping doesn't work,
as it leaves the final binary untouched.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Sonic Zhang <sonic.zhang@analog.com>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reviewed-by: Sonic Zhang <sonic.zhang@analog.com>
This commit enables Kconfig.
Going forward, we use Kconfig for the board configuration.
mkconfig will never be used. Nor will include/config.mk be generated.
Kconfig must be adjusted for U-Boot because our situation is
a little more complicated than Linux Kernel.
We have to generate multiple boot images (Normal, SPL, TPL)
from one source tree.
Each image needs its own configuration input.
Usage:
Run "make <board>_defconfig" to do the board configuration.
It will create the .config file and additionally spl/.config, tpl/.config
if SPL, TPL is enabled, respectively.
You can use "make config", "make menuconfig" etc. to create
a new .config or modify the existing one.
Use "make spl/config", "make spl/menuconfig" etc. for spl/.config
and do likewise for tpl/.config file.
The generic syntax of configuration targets for SPL, TPL is:
<target_image>/<config_command>
Here, <target_image> is either 'spl' or 'tpl'
<config_command> is 'config', 'menuconfig', 'xconfig', etc.
When the configuration is done, run "make".
(Or "make <board>_defconfig all" will do the configuration and build
in one time.)
For futher information of how Kconfig works in U-Boot,
please read the comment block of scripts/multiconfig.py.
By the way, there is another item worth remarking here:
coexistence of Kconfig and board herder files.
Prior to Kconfig, we used C headers to define a set of configs.
We expect a very long term to migrate from C headers to Kconfig.
Two different infractructure must coexist in the interim.
In our former configuration scheme, include/autoconf.mk was generated
for use in makefiles.
It is still generated under include/, spl/include/, tpl/include/ directory
for the Normal, SPL, TPL image, respectively.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Simon Glass <sjg@chromium.org>
We currently limit ourself to 16 characters for the device name to read
the environment from. This is insufficient for /dev/mmcblk0boot1 to
work for example. Switch to '%ms' which gives us a dynamically
allocated buffer instead. We're short lived enough to not bother
free()ing the buffer.
Signed-off-by: Tom Rini <trini@ti.com>
Implement support for encrypting/decrypting the environment block
into the tools/env/fw_* tools. The cipher used is AES 128 CBC and
the implementation depends solely on components internal to U-Boot.
To allow building against the internal AES library, the library did
need minor adjustments to not include U-Boot's headers which are not
wanted to be included and define missing types.
Signed-off-by: Marek Vasut <marex@denx.de>
Prior to Kbuild, $(TOPDIR) or $(SRCTREE) was used for
pointing to the top of source directory.
(No difference between the two.)
In Kbuild style, $(srctree) is used for instead.
This commit renames SRCTREE to srctree and deletes the
defition of SRCTREE.
Note that SRCTREE in scripts/kernel-doc, scripts/docproc.c,
doc/DocBook/Makefile should be keep.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Some NOR flash devices have a small erase block size. For example, the
Micron N25Q512 can erase in 4K blocks. These devices expose a bug in
fw_env.c where flash_write_buf() incorrectly calculates bytes written
and attempts to write past the environment sectors. Luckily, a range
check prevents any real damage, but this does cause fw_setenv to fail
with an error.
This change corrects the write length calculation.
The bug was introduced with commit 56086921 from 2008 and only affects
configurations where the erase block size is smaller than the total
environment data size.
Signed-off-by: Dustin Byford <dustin@cumulusnetworks.com>
The assumed number of environment sectors (always 1) leads to an
incorrect top_of_range calculation in fw.env.c when a flash device has
an erase block size smaller than the environment data size (number of
environment sectors > 1).
This change updates the default number of environment sectors to at
least cover the size of the environment.
Also corrected a false statement about the number of sectors column in
fw_env.config.
Signed-off-by: Dustin Byford <dustin@cumulusnetworks.com>
fw_printenv is a program which mostly runs on the target Linux.
Before switching to Kbuild, we needed to set HOSTCC at the
command line like this:
make HOSTCC=<your CC cross-compiler> env
Going forward we can cross compile it by specifying CROSS_COMPILE:
make CROSS_COMPILE=<your cross-compiler prefix> env
This looks more natural.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Tested-by: Gerhard Sittig <gsi@denx.de>
This commit merges commonly-used header include paths
to UBOOTINCLUDE and NOSTDINC_FLAGS variables, which are placed
at the top Makefile.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Before this commit, makefiles under tools/ directory
were implemented with their own way.
This commit refactors them by using "hostprogs-y" variable.
Several C sources have been added to wrap other C sources
to simplify Makefile.
For example, tools/crc32.c includes lib/crc32.c
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
In-tree build:
- Do not create a symbolic link
from include/asm to arch/${ARCH}/include/asm
- Add ${SRCTREE}/arch/arm/include into the header search path
Out-of-tree build:
- Do not create a directory ${OBJTREE}/include2
- Do not create a symbolic link
from ${OBJTREE}/include2/asm to ${SRCTREE}/arch/${ARCH}/include/asm
- Add ${SRCTREE}/arch/arm/include into the header search path
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
UBI is a better place for the environment on NAND devices because it
handles wear-leveling and bad blocks.
Gluebi is needed in Linux to access the env as an MTD partition.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
In certain cases, memory device is present as flat file or block device (via
mmc or mtdblock layer). Do not attempt MTD operations against it.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
When using open(), the O_CREAT flag must be given a mode, otherwise it
uses random garbage from the stack. Also, it can fail to build:
In file included from /usr/include/fcntl.h:290:0,
from fw_env_main.c:42:
In function 'open',
inlined from 'main' at fw_env_main.c:97:9:
/usr/include/bits/fcntl2.h:50:24: error: call to '__open_missing_mode' declared
with attribute error: open with O_CREAT in second argument needs 3 arguments
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
This variable is assigned by a size_t, and is printed that way, but is
incorrectly declared as an int. Which means we get warnings:
fw_env.c: In function 'fw_setenv':
fw_env.c:409:5: warning: format '%zu' expects argument of type 'size_t',
but argument 3 has type 'int' [-Wformat]
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Use the variable access flags to implement the protection for ethaddr
and serial# instead of hard-coding them.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Currently just validates variable types as decimal, hexidecimal,
boolean, ip address, and mac address. Call
env_acl_validate_setenv_params() from setenv() in fw_env.c.
If the entry is not found in the env .flags, then look in the static
one. This allows the env to override the static definitions, but prevents
the need to have every definition in the environment distracting you.
Need to build in _ctype for isdigit for Linux.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
There used to be a huge structure duplicated 3 times in the source.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Tom Rini <trini@ti.com>
Provide more information when using redundant environments
Consistently print debug info to stderr
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Fix crash introduced by a073d63a36524453a817ab029fad5b188f46127e
when attempting to delete a variable.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
This was introduced in:
8679d0ffdcc0beafea8e6942c0c67cf859afa18e -
COMMON: Use __stringify() instead of MK_STR()
The header is now needed since common.h is not included in this tool.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Add a mention of the lock file to the README for the fw_printenv tool.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Reported-by: Luka Perkov <uboot@lukaperkov.net>
The length included the name length, and then it was subtracted back
out on each use. Now we don't include it in the first place. Also
realloc as we process arguments and eliminate memset. Use memcpy
instead of manually copying each byte.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Originally added in aa701b9433
Before this patch, there was a hard-coded env that was used as default
if the env in flash is detected as invalid. Now this tool (compiled
for a given board) will share the default env with the u-boot for the
board.
Fix include of config.h
Need to define "TEXT_BASE" when building the fw_env tool so that the
default env will be correct for environments which use it.
Define __ASSEMBLY__ when calling #include <config.h> so that we only
get #defines (all we're interested in).
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Kill multiple occurances and redeclaration of MK_STR
in favor of __stringify().
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Signed-off-by: Tom Rini <trini@ti.com>
Commit 5e724ca did the same thing for env_common and env_embedded, but forgot
fw_env.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Cc: Wolfgang Denk <wd@denx.de>
This patch allows the U-Boot user space companion utility, fw_setenv,
to overwrite the 'ethaddr' key/value pair if the current value is set
to a per-board-configured default.
This change allows 'fw_setenv' to match the behavior of 'setenv' /
'env set' on the U-Boot command line.
Signed-off-by: Grant Erickson <marathon96@gmail.com>
Fixed excessive white space.
Signed-off-by: Wolfgang Denk <wd@denx.de>
The README file lists 4 defined that were not actually present in the .h
file but that were needed to get things working with settings compiled in.
They are
Added these to the .h file
(the values above are the ones from the README file)
Signed-off-by: Frans Meulenbroeks <fransmeulenbroeks@gmail.com>
Instead of linking the file into $(obj) tree use directly the source file.
This also prevents littered source tree if building not out-of-tree.
Signed-off-by: Andreas Bießmann <biessmann@corscience.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Remove MK_STR from places that consume CONFIG_BOOTFILE to force all definitions to be string literals.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Cc: Joe Hershberger <joe.hershberger@gmail.com>
Cc: Wolfgang Denk <wd@denx.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Remove MK_STR from places that consume CONFIG_ROOTPATH to force all definitions to be string literals.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Cc: Joe Hershberger <joe.hershberger@gmail.com>
Cc: Wolfgang Denk <wd@denx.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Patch fixes this issue:
fw_env.c: In function ‘fw_setenv’:
fw_env.c:492:5: warning: format ‘%u’ expects argument of type ‘unsigned int’, but argument 3 has type ‘size_t’ [-Wformat]
fw_env.c: In function ‘flash_write_buf’:
fw_env.c:806:6: warning: format ‘%u’ expects argument of type ‘unsigned int’, but argument 3 has type ‘size_t’ [-Wformat]
Signed-off-by: Luka Perkov <lists@lukaperkov.net>
Acked-by: Mike Frysinger <vapier@gentoo.org>
The 'trab' board configuration is broken, and there is nobody who is
interested and willing to fix it. Drop it.
This includes support for VFD displays which have always been used by
this board only.
Signed-off-by: Wolfgang Denk <wd@denx.de>
This fixes two bugs with comparison of redundant environment flags on
read.
flag0 and flag1 in fw_env_open() were declared signed instead of
unsigned char breaking BOOLEAN mode "== 0xFF" tests and in INCREMENTAL
mode the wrong environment would be chosen where the flag values are
127 and 128 (either way round). With both flags over 128, both signs
flipped and the logic worked by happy accident.
Also there was a logic bug in the INCREMENTAL test (after signedness was
fixed) in the case flag0=0, flag1=255, env 1 would be incorrectly chosen.
Fix both of these.
Signed-off-by: Jon Povey <jon.povey@racelogic.co.uk>
