Where to get "esp32ulp-elf-as"?

[tony2simmy]

My develop environment is the cygwin in Win7. When i compile the example of 'ulp' that it is located in 'esp-idf/examples/system/',some error happen.
// Error log.
CPP pulse_cnt.S
ULP_AS pulse_cnt.ulp.o
make[1]: esp32ulp-elf-as: Command not found
make[1]: *** [/cygdrive/e/Aithinker/13_Aithinker_IDE/AiThinkerIDE_V0.5/cygwin/home/aithinker/project/esp-idf/components/ulp/component_ulp_common.mk:41: pulse_cnt.ulp.o] Error 127
make: *** [/cygdrive/e/Aithinker/13_Aithinker_IDE/AiThinkerIDE_V0.5/cygwin/home/aithinker/project/esp-idf/make/project.mk:386: main-build] Error 2
How to solve it?

[ESP_igrr]

Please follow the instructions in http://esp-idf.readthedocs.io/en/latest ... -toolchain. Latest download links for the ULP toolchain are listed on https://github.com/espressif/binutils-e ... #downloads.

[tony2simmy]

Please follow the instructions in http://esp-idf.readthedocs.io/en/latest ... -toolchain. Latest download links for the ULP toolchain are listed on https://github.com/espressif/binutils-e ... #downloads.

Thank you very much.