I tend to automate most of the boring and repetitive tasks like firmware
flashing, build config reconfiguration etc., so I always end up adding
`include local.mk` as a last line in my Makefile, where local.mk is
usually symlink to some other place, just to not accidentally delete it
during `git clean`.
Carrying this single uncommited modification along in the development
process is quite PITA, because it's causing problems during Git
workflow, while rebasing etc.
I hope, that I'm not alone using similar workflow, so I believe, that
this modification might be useful for others as well.
Signed-off-by: Petr Štetiar <ynezz@true.cz>
Change capitalization from spaces to tabs in order to match
the style of the file.
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
[fix capitalization in commit title, add short description]
Signed-off-by: David Bauer <mail@david-bauer.net>
Hardware spec of DIR-842 C2:
SoC: QCA9563
DRAM: 128MB DDR2
Flash: 16MB SPI-NOR
Switch: QCA8337N
WiFi 5.8GHz: QCA9888
WiFi 2.4Ghz: QCA9563
USB: 2.0
Flash instructions:
1. Upgrade the factory.bin through the factory web interface or
the u-boot failsafe interface.
The firmware will boot up correctly for the first time.
Do not power off the device after OpenWrt has booted.
Otherwise the u-boot will enter failsafe mode as the checksum
of the firmware has been changed.
2. Upgrade the sysupgrade.bin in OpenWrt.
After upgrading completes the u-boot won't complain about the
firmware checksum and it's OK to use now.
3. If you powered off the device before upgrading the sysupgrade.bin,
just upgrade the factory.bin through the u-boot failsafe interface
and then goto step 2.
Signed-off-by: Jackson Lim <jackcolentern@gmail.com>
[Reword reset-hog comment, fix formatting]
Signed-off-by: David Bauer <mail@david-bauer.net>
Newifi D1 is shipped with an 8GB microSD card in its SD slot
Without SD driver users would not be able to use it unless manually installed
Signed-off-by: DENG Qingfang <dengqf6@mail2.sysu.edu.cn>
Making all in tests
depbase=`echo handshake_table.o | sed 's|[^/]*$|.deps/&|;s|\.o$||'`;\
gcc -DPACKAGE_NAME=\"libressl\" -DPACKAGE_TARNAME=\"libressl\" -DPACKAGE_VERSION=\"2.9.2\" -DPACKAGE_STRING=\"libressl\ 2.9.2\" -DPACKAGE_BUGREPORT=\"\" -DPACKAGE_URL=\"\" -DPACKAGE=\"libressl\" -DVERSION=\"2.9.2\" -DSTDC_HEADERS=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_STAT_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1 -DHAVE_STRINGS_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 -DHAVE_UNISTD_H=1 -DHAVE_DLFCN_H=1 -DLT_OBJDIR=\".libs/\" -DHAVE_SYMLINK=1 -DHAVE_ERR_H=1 -DHAVE_READPASSPHRASE_H=1 -DHAVE_ASPRINTF=1 -DHAVE_MEMMEM=1 -DHAVE_READPASSPHRASE=1 -DHAVE_STRLCAT=1 -DHAVE_STRLCPY=1 -DHAVE_STRNDUP=1 -DHAVE_STRNLEN=1 -DHAVE_STRSEP=1 -DHAVE_TIMEGM=1 -DHAVE_GETPROGNAME=1 -DHAVE_SYSLOG=1 -DHAVE_POLL=1 -DHAVE_SOCKETPAIR=1 -DHAVE_ARC4RANDOM=1 -DHAVE_ARC4RANDOM_BUF=1 -DHAVE_ARC4RANDOM_UNIFORM=1 -DHAVE_TIMINGSAFE_BCMP=1 -DHAVE_CLOCK_GETTIME=1 -DHAVE_VA_COPY=1 -DHAVE___VA_COPY=1 -DSIZEOF_TIME_T=8 -I. -I../include -I../include/compat -DLIBRESSL_INTERNAL -D__BEGIN_HIDDEN_DECLS= -D__END_HIDDEN_DECLS= -I ../crypto/modes -I ../crypto/asn1 -I ../ssl -I ../tls -I ../apps/openssl -I ../apps/openssl/compat -D_PATH_SSL_CA_FILE=\"../apps/openssl/cert.pem\" -I/Users/kevin/wrt/staging_dir/host/include -D__STRICT_ALIGNMENT -O2 -I/Users/kevin/wrt/staging_dir/host/include -fpic -Wall -std=gnu99 -fno-strict-aliasing -fno-strict-overflow -D_FORTIFY_SOURCE=2 -fstack-protector-strong -Qunused-arguments -Wno-pointer-sign -MT handshake_table.o -MD -MP -MF $depbase.Tpo -c -o handshake_table.o handshake_table.c &&\
mv -f $depbase.Tpo $depbase.Po
make[4]: *** No rule to make target `/Users/kevin/wrt/build_dir/host/libressl-2.9.2/crypto/.libs/libcrypto_la-cpuid-macosx-x86_64.o', needed by `handshake_table'. Stop.
make[3]: *** [all-recursive] Error 1
A similar error & clues from
e783d60473
"
LibreSSL 2.9.1 now has a test that requires libtls.a, however, when building a
shared library only build, the --disable-static flag is passed to libressl,
which prevents the building of libtls.a.
With libtls.a not being built, the following error occurs:
libressl-2.9.1/tls/.libs/libtls.a', needed by 'handshake_table'. Stop.
There are three options to fix this:
1) Stick with autotools, and provide a patch that removes building anything in
the tests folder.
2) Pass --enable-static to LIBRESSL_CONF_OPTS
3) Change the package type to cmake, as a cmake build does not have this issue."
It appears we cannot change to cmake because cmake has a dependency on
an ssl library.
Take option 1 and do not build the tests.
Also take the opportunity to remove man page building as well.
Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
1) nand_do_upgrade() is always called by a target code
2) nand_do_upgrade() starts with calling platform_nand_pre_upgrade()
It means there is no need for the platform_nand_pre_upgrade() callback
at all. All code that was present there could bo moved & simplly called
by a target right before the nand_do_upgrade().
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
1) RAMFS_COPY_BIN and RAMFS_COPY_DATA can be defined at top of the file
like it's done for all other targets.
2) fw_printenv.lock can be created one step later in the
platform_do_upgrade(). It seems to be working well on many other
targets.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
This doesn't include 9ff8614a3dbe ("brcmfmac: use separate Kconfig file
for brcmfmac") due to a few conflicts with backports changes.
An important change is:
[PATCH 2/7] brcmfmac: change the order of things in brcmf_detach()
which fixes a rmmod crash in the brcmf_txfinalize().
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Fixes following errors:
src/mkfwimage.c:279:8: error: format specifies type 'long' but the argument has type 'off_t' (aka 'long long') [-Werror,-Wformat]
d->stats.st_size,
^~~~~~~~~~~~~~~~
src/mkfwimage.c:280:8: error: format specifies type 'long' but the argument has type 'long long' [-Werror,-Wformat]
d->partition_length - d->stats.st_size);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mkfwimage.c:378:6: error: format specifies type 'unsigned long' but the argument has type 'long long' [-Werror,-Wformat]
d->stats.st_size - d->partition_length);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Reported-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
Signed-off-by: Petr Štetiar <ynezz@true.cz>
src/mkfwimage.c:276:8: error: format '%lld' expects argument of type 'long long int', but argument 4 has type '__off_t' {aka 'const long int'} [-Werror=format=]
src/fw.h:71:36: error: format '%llu' expects argument of type 'long long unsigned int', but argument 6 has type '__off_t' {aka 'long int'} [-Werror=format=]
inlined from 'main' at src/mkfwimage.c:543:12:
/string_fortified.h:106:10: error: '__builtin_strncpy' output truncated before terminating nul copying 4 bytes from a string of the same length [-Werror=stringop-truncation]
inlined from 'write_part' at src/mkfwimage.c:235:2,
string_fortified.h:106:10: error: '__builtin_strncpy' specified bound 16 equals destination size [-Werror=stringop-truncation]
inlined from 'main' at src/mkfwimage.c:477:5:
string_fortified.h:106:10: error: '__builtin_strncpy' specified bound 256 equals destination size [-Werror=stringop-truncation]
inlined from 'main' at src/mkfwimage.c:496:5:
string_fortified.h:106:10: error: '__builtin_strncpy' specified bound 4096 equals destination size [-Werror=stringop-truncation]
inlined from 'main' at src/mkfwimage.c:481:5:
string_fortified.h:106:10: error: '__builtin_strncpy' specified bound 4096 equals destination size [-Werror=stringop-truncation]
inlined from 'main' at src/mkfwimage.c:485:5:
string_fortified.h:106:10: error: '__builtin_strncpy' specified bound 16 equals destination size [-Werror=stringop-truncation]
Runtested on ath79 and UBNT Bullet M XW.
Signed-off-by: Petr Štetiar <ynezz@true.cz>
Fix 4 errors reported by gcc 9
3 mismatched format type errors
1 unused variable error
Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
While looking at the ath25 build breakage of 19.07 images today I've
encountered following error:
mkfwimage -B XS5 -v [...] ath25-ubnt5-squashfs-sysupgrade.bin.new
ERROR: Failed creating firmware layout description - error code: -2
Which is barely human readable and needs poking into the source code, so
this patch makes the error more verbose and usable by mere mortals.
Signed-off-by: Petr Štetiar <ynezz@true.cz>
Let's enforce additional automatic checks enforced by the compiler in
order to catch possible errors during compilation.
Signed-off-by: Petr Štetiar <ynezz@true.cz>
the ath10k-ct package ships multiple versions of the ath10k-ct driver,
OpenWrt currently only uses the version 4.19, but we still ship some
patches for older versions. Remove all patches only touching older
versions and also remove the patch for older versions from patches which
do the same changes to multiple versions of ath10k-ct.
This removes some unneeded patches, the end binary should stay the same.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
This updates mac80211 to version 5.2-rc7, this contains all the changes
to the wireless subsystem up to Linux 5.2-rc7.
* The removed patches are applied upstream
* b43 now uses kmod-lib-cordic
* Update the nl80211.h file in iw to match backports version.
* Remove the two backports from kernel 4.9, they were needed for mt76,
but that can use the version from backports now, otherwise they
collide and cause compile errors.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
TP-Link Archer C60 v2 is a dual-band AC1350 router,
based on Qualcomm/Atheros QCA9561 + QCA9886.
Specification:
- 775/650/258 MHz (CPU/DDR/AHB)
- 64 MB of RAM (DDR2)
- 8 MB of FLASH (SPI NOR)
- 3T3R 2.4 GHz
- 2T2R 5 GHz
- 5x 10/100 Mbps Ethernet
- 7x LED, 2x button
- UART header on PCB
Flash instruction (WebUI):
Download *-factory.bin image and upload it via the firmwary upgrade
function of the stock firmware WebUI.
Flash instruction (TFTP):
1. Set PC to fixed IP address 192.168.0.66
2. Download *-factory.bin image and rename it to tp_recovery.bin
3. Start a tftp server with the file tp_recovery.bin in its root
directory
4. Turn off the router
5. Press and hold reset button
6. Turn on router with the reset button pressed and wait ~15 seconds
7. Release the reset button and after a short time the firmware should
be transferred from the tftp server
8. Wait ~30 second to complete recovery
Flash instruction (under U-Boot, using UART):
tftp 0x81000000 ...-sysupgrade.bin
erase 0x9f030000 +$filesize
cp.b $fileaddr 0x9f030000 $filesize
reset
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
TP-Link Archer C60v1 is a dual-band AC1350 router,
based on Qualcomm/Atheros QCA9561+QCA9886.
Specification:
- 775/650/258 MHz (CPU/DDR/AHB)
- 64 MB of RAM (DDR2)
- 8 MB of FLASH (SPI NOR)
- 3T3R 2.4 GHz
- 2T2R 5 GHz
- 5x 10/100 Mbps Ethernet
- 7x LED, 2x button
- UART header on PCB
Flash instruction (WebUI):
Download *-factory.bin image and upload it via the firmwary upgrade
function of the stock firmware WebUI.
Flash instruction (TFTP):
1. Set PC to fixed ip address 192.168.0.66
2. Download *-factory.bin image and rename it to tp_recovery.bin
3. Start a tftp server with the file tp_recovery.bin in its root directory
4. Turn off the router
5. Press and hold Reset button
6. Turn on router with the reset button pressed and wait ~15 seconds
7. Release the reset button and after a short time
the firmware should be transferred from the tftp server
8. Wait ~30 second to complete recovery.
Flash instruction under U-Boot, using UART:
1. tftp 0x81000000 ...-sysupgrade.bin
2. erase 0x9f020000 +$filesize
3. cp.b $fileaddr 0x9f020000 $filesize
4. reset
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
TP-Link CPE510-v2/v3 is an outdoor wireless CPE for 5 GHz with
one Ethernet port based on Atheros AR9344
Specifications:
- Based on the same underlying hardware as the TP-Link CPE510
- Power, LAN, and 4 green LEDs
- 1 10/100Mbps Shielded Ethernet Port (Passive PoE in)
- Built-in 13dBi 2x2 dual-polarized directional MIMO antenna
- Adjustable transmission power from 0 to 23dBm/200mw
Flashing instructions:
Flash factory image through stock firmware WEB UI
or through TFTP
To get to TFTP recovery just hold reset button while powering on for
around 4-5 seconds and release.
Rename factory image to recovery.bin
Stock TFTP server IP:192.168.0.100
Stock device TFTP adress:192.168.0.254
Signed-off-by: Andrew Cameron <apcameron@softhome.net>
[whitespace fixes]
Signed-off-by: Petr Štetiar <ynezz@true.cz>
Trendnet TEW-823DRU is a dual-band AC1750 router.
The router is based on Qualcomm/Atheros QCA9558 + QCA9880.
Specification:
720 MHz CPU
256 MB of RAM
16 MB of FLASH
3T3R 2.4 GHz
3T3R 5 GHz
5x 10/100/1000 Mbps Ethernet
Firmware can be flashed from the web interface. Tested on 3 routers
with no issues.
Signed-off-by: Pramod Pancha <pancha@vill.com>
[whitespace fixes]
Signed-off-by: Petr Štetiar <ynezz@true.cz>
TP-Link RE650 v1 is a dual-band AC2600 range extender,
based on MediaTek MT7621A and MT7615E. According to the
wikidevi entry for RE650 this device is identical with
TP-Link RE500 as hardware. This patch supports only RE650.
Hardware specification:
- SoC 880 MHz - MediaTek MT7621AT
- 128 MB of DDR3 RAM
- 16 MB - Winbond 25Q128FVSG
- 4T4R 2.4 GHz - MediaTek MT7615E
- 4T4R 5 GHz - MediaTek MT7615E
- 1x 1 Gbps Ethernet - MT7621AT integrated
- 7x LEDs (Power, 2G, 5G, WPS(x2), Lan(x2))
- 4x buttons (Reset, Power, WPS, LED)
- UART header (J1) - 2:GND, 3:RX, 4:TX
Serial console @ 57600,8n1
Flash instructions:
Upload
openwrt-ramips-mt7621-tplink_re650-v1-squashfs-factory.bin
from the RE650 web interface.
TFTP recovery to stock firmware:
Unfortunately, I can't find an easy way to recover the RE
without opening the device and using modified binaries. The
TFTP upload will only work if selected from u-boot, which
means you have to open the device and attach to the serial
console. The TFTP update procedure does *not* accept the
published vendor firmware binaries. However, it allows to
flash kernel + rootfs binaries, and this works if you have
a backup of the original contents of the flash. It's probably
possible to create special image out of the vendor binaries
and use that as recovery image.
Signed-off-by: Georgi Vlaev <georgi.vlaev@gmail.com>
[re-added variables for kernel header]
Signed-off-by: David Bauer <mail@david-bauer.net>
While compile checking mtd changes in PR#1359 I've noticed following
compiler warnings and cleaned them up:
fis.c: In function 'fis_remap':
fis.c:143:25: warning: variable 'redboot' set but not used [-Wunused-but-set-variable]
struct fis_image_desc *redboot = NULL;
^~~~~~~
fis.c:142:25: warning: variable 'fisdir' set but not used [-Wunused-but-set-variable]
struct fis_image_desc *fisdir = NULL;
^~~~~~
Signed-off-by: Petr Štetiar <ynezz@true.cz>
This board was used in dual-band 802.11n enterprise access points, models
BSAP-1800v2 and BSAP-1840, introduced in 2010 by Bluesocket, which was
acquired by Adtran in 2011, who has now EOL'ed them. They differed only in
that the BSAP-1840's antennae were detachable, while the BSAP-1800v2's were
inside the case. They have an external RJ-45 console port, which works with
standard Cisco 72-3383-01 console cables.
Specification:
- System-On-Chip: AR7161
- CPU/Speed: 600 MHz
- Flash-Chip: Macronix MX25L12845E
- Flash size: 16 MiB
- RAM: 64 MiB
- Wireless No1: Lite-On WN2601A card: AR9160/AR9103 2.4GHz 802.11bgn
- Wireless No2: Lite-On WN2502A card: AR9160/AR9106 5GHz 802.11an
- PHY: Vitesse VSC8601, Rev. B
Installation:
1. Connect to the serial console using a terminal that supports YMODEM at
115200 bps, 8 data bits, no parity, 1 stop bit
2. Interrupt the bootloader using its password, which is: r00t
3. Issue the "fis init" command, confirming if prompted
4. Look at the length of the openwrt-ath79-generic-*-squashfs-kernel.bin
file, and substitute it below, instead of where I have "LeNgTh"
5. Issue the following command, and upload this file using YMODEM protocol
load -r -v -b 0x80060000 -m ymodem
6. Issue the following commands, substituting as mentioned above:
fis create -b 0x80060000 -l LeNgTh vmlinux_2
load -r -v -b 0x80100000 -m ymodem
7. Using YMODEM, upload openwrt-ath79-generic-*-squashfs-rootfs.bin
8. Issue the "fis free" command, and for the first range in its response,
use a hexadecimal calculator to subtract the start from the end in order
to substitute it below, with the leading "0x" to specify it in
hexadecimal, instead of where I have "LeNgTh"
9. Issue the following commands, substituting as mentioned above:
fis create -b 0x80100000 -l LeNgTh -e 0 -r 0 rootfs
reset
10.Wait for the status LED to go solid green
Tested-by: Brian Gonyer <bgonyer@gmail.com>
Signed-off-by: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
[fixed obsolete $ARGV in platform_do_upgrade]
Signed-off-by: Petr Štetiar <ynezz@true.cz>
The Bluesocket BSAP1880 board has a Vitesse PHY, for which the driver was
not being included, and its RedBoot directory block is earlier in the
flash than the search was allowing. This commit prepares for supporting it.
Signed-off-by: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
The ag71xx code did not include a case for the "rgmii-id" PHY mode in the
code. There are devices that need this mode, so I'm adding it.
Signed-off-by: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
The code for calculating the CRC32 signatures for RedBoot FIS partitions
was already included, but for unknown reasons, it was never invoked. Some
bootloaders enforce checking these for loaded kernels, so they should be
written. This patch does so.
Tested-by: Brian Gonyer <bgonyer@gmail.com>
Signed-off-by: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
To configure the list of allowable TLS 1.3 ciphersuites, the option
tls_ciphersuites is used instead of tls_ciphers.
Signed-off-by: Martin Schiller <ms@dev.tdt.de>
Fix the following compilation error when using linux 4.19 on brcm47xx:
drivers/watchdog/old_gpio_wdt.c:236:2: error: implicit declaration of function 'setup_timer'
setup_timer was removed and replaced by timer_setup in linux >=4.15:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=513ae785
Update the patch to use the timer_setup interface
Signed-off-by: Zachary Cook <zachcook1991@gmail.com>
It was reported in FS#2385, that Carambola2 doesn't currently have
working watchdog so fix it by adding watchdog node.
Ref: FS#2385
Signed-off-by: Petr Štetiar <ynezz@true.cz>
ELECOM WRC-1167GHBK2-S has a MediaTek MT7615D chip for 2.4/5 GHz
wireless.
A driver package for MT7615 chip is added to OpenWrt in
a0e5ca4f35,
so add preliminary MT7615 chip support for WRC-1167GHBK2-S.
Note: Currently, DBDC mode for MT7615 is not supported in mt76 driver.
Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com>
Redirect the build output to PKG_BUILD_DIR instead of copying over
complete source code.
Build tested on following targets:
x86/64 ar7/generic ipq40xx/generic imx6/generic ar71xx/generic
ramips/mt7621 ramips/mt7620 sunxi/cortexa7
Run tested on imx6/apalis.
Signed-off-by: Petr Štetiar <ynezz@true.cz>
Drop 211-host_tools_portability.patch which is breaking perf build on
4.19 kernels by removing the include directory from the host's CFLAGS
leading to the following build breakage:
pmu-events/jevents.c:48:10: fatal error: linux/list.h: No such file or directory
#include <linux/list.h>
^~~~~~~~~~~~~~
Signed-off-by: Petr Štetiar <ynezz@true.cz>
jffs2reset is used to cleanup the rootfs_data overlay, but it's
currently missing in the ramfs during sysupgrade leading to the
following error:
Switching to ramdisk...
Performing system upgrade...
/lib/upgrade/do_stage2: line 27: jffs2reset: not found
Fixes: 2f1a11d008 ("imx6: apalis: fix config survival after sysupgrade -n")
Signed-off-by: Petr Štetiar <ynezz@true.cz>
We can't use $board_name in sysupgrade paths for kernel and rootfs as we
currently generate one image which could be used on two different base
boards.
Signed-off-by: Petr Štetiar <ynezz@true.cz>
Many Atom-based embedded/industrial x86 boards can't run 64bit operating
systems due to either processor or board firmware limitations, but they
have modern interfaces (PCIe) or have modern Intel gigabit controllers
onboard. With the current default package selection for x86 Generic
target their network won't work.
Add the modern gigabit network modules needed or most likely going to be
used as add-in cards, similar to what is the list on x86_64 target.
Signed-off-by: Alberto Bursi <alberto.bursi@outlook.it>
[fixed whitespace issue]
Signed-off-by: Petr Štetiar <ynezz@true.cz>
By default, set BE tx queue TXOP limit to 1.0 in the hostapd config
Many vendor drivers are doing similar things to boost throughput.
On MT7612 under ideal conditions, it improves tx throughput from 470 Mbit/s
to about 570 Mbit/s.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
sysupgrade passes image path to platform_check_image() as an argument so
it can be simply accessed using $1
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Petr Štetiar
Adrian Schmutzler
Jackson Lim
Hans Dedecker
DENG Qingfang
Kevin Darbyshire-Bryant
Rafał Miłecki
Roman Yeryomin
Hauke Mehrtens
INAGAKI Hiroshi
Andrew Cameron
Pramod Pancha
Christoph Krapp
Georgi Vlaev
Daniel Gimpelevich
Martin Schiller
Zachary Cook
Alberto Bursi
Felix Fietkau