Good morning guys,
I’m building the u-boot by passing those commands :
$ cd bootloader/uboot
$ ./mk kvim3
i have got this error 
*
Clean up
make[1]: /opt/toolchains/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux/bin/aarch64-none-elf-gcc: Command not found
/bin/sh: 1: /opt/toolchains/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux/bin/aarch64-none-elf-gcc: not found
dirname: missing operand
Try 'dirname --help' for more information.
CLEAN scripts/basic
CLEAN scripts/kconfig
CLEAN include/config include/generated
CLEAN .config include/config.h
select bl33:
Compile config: kvim3
make[1]: /opt/toolchains/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux/bin/aarch64-none-elf-gcc: Command not found
/bin/sh: 1: /opt/toolchains/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux/bin/aarch64-none-elf-gcc: not found
dirname: missing operand
Try 'dirname --help' for more information.
HOSTCC scripts/basic/fixdep
GEN ./Makefile
HOSTCC scripts/kconfig/conf.o
SHIPPED scripts/kconfig/zconf.tab.c
SHIPPED scripts/kconfig/zconf.lex.c
SHIPPED scripts/kconfig/zconf.hash.c
HOSTCC scripts/kconfig/zconf.tab.o
In file included from scripts/kconfig/zconf.tab.c:2547:
../scripts/kconfig/confdata.c: In function ‘conf_write’:
../scripts/kconfig/confdata.c:767:19: warning: ‘%s’ directive writing likely 7 or more bytes into a region of size between 1 and 4097 [-Wformat-overflow=]
767 | sprintf(newname, "%s%s", dirname, basename);
| ^~~~~~
../scripts/kconfig/confdata.c:767:19: note: assuming directive output of 7 bytes
In file included from /usr/include/stdio.h:867,
from scripts/kconfig/zconf.tab.c:84:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:36:10: note: ‘__builtin___sprintf_chk’ output 1 or more bytes (assuming 4104) into a destination of size 4097
36 | return __builtin___sprintf_chk (__s, __USE_FORTIFY_LEVEL - 1,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
37 | __bos (__s), __fmt, __va_arg_pack ());
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from scripts/kconfig/zconf.tab.c:2547:
../scripts/kconfig/confdata.c:770:20: warning: ‘.tmpconfig.’ directive writing 11 bytes into a region of size between 1 and 4097 [-Wformat-overflow=]
770 | sprintf(tmpname, "%s.tmpconfig.%d", dirname, (int)getpid());
| ^~~~~~~~~~~~~~~~~
In file included from /usr/include/stdio.h:867,
from scripts/kconfig/zconf.tab.c:84:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:36:10: note: ‘__builtin___sprintf_chk’ output between 13 and 4119 bytes into a destination of size 4097
36 | return __builtin___sprintf_chk (__s, __USE_FORTIFY_LEVEL - 1,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
37 | __bos (__s), __fmt, __va_arg_pack ());
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
HOSTLD scripts/kconfig/conf
#
# configuration written to .config
#
*****Compile tools*****
parse build done
export CONFIG_SYSTEM_AS_ROOT
Build uboot...Please Wait...systemroot...null...
make[1]: /opt/toolchains/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux/bin/aarch64-none-elf-gcc: Command not found
/bin/sh: 1: /opt/toolchains/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux/bin/aarch64-none-elf-gcc: not found
dirname: missing operand
Try 'dirname --help' for more information.
GEN ./Makefile
scripts/kconfig/conf --silentoldconfig Kconfig
CHK include/config.h
UPD include/config.h
GEN include/autoconf.mk
/bin/sh: 1: /opt/toolchains/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux/bin/aarch64-none-elf-gcc: not found
GEN include/autoconf.mk.dep
/bin/sh: 1: /opt/toolchains/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux/bin/aarch64-none-elf-gcc: not found
make[3]: *** [../scripts/Makefile.autoconf:64: include/autoconf.mk] Error 1
make[3]: *** Waiting for unfinished jobs....
make[3]: *** [../scripts/Makefile.autoconf:40: include/autoconf.mk.dep] Error 1
make[2]: *** [../Makefile:480: silentoldconfig] Error 1
make[1]: *** No rule to make target 'include/config/auto.conf', needed by 'include/config/uboot.release'. Stop.
make: *** [Makefile:147: sub-make] Error 2
Error: U-boot build failed... abort
Can yoou please help me and thanks