recipe for target 'build-GENERIC_SPIRAM/bootloader.elf' failed #261
Description
I'm compiling the firmware of esp32. I encountered the following problems and asked for assistance；
xkp@xkp-VirtualBox:~/esp32/micropython/ports/esp32$ make
MicroPython v1.13-30-g1d344f446-dirty
Use make V=1 or set BUILD_VERBOSE in your environment to increase build verbosity.
Building with ESP IDF v4
LINK build-GENERIC_SPIRAM/bootloader.elf
/home/xkp/esp32/xtensa-esp32-elf/bin/../lib/gcc/xtensa-esp32-elf/5.2.0/../../../../xtensa-esp32-elf/bin/ld: cannot find -lrtc
collect2: error: ld returned 1 exit status
Makefile:979: recipe for target 'build-GENERIC_SPIRAM/bootloader.elf' failed
make: *** [build-GENERIC_SPIRAM/bootloader.elf] Error 1
xkp@xkp-VirtualBox:~/esp32/micropython/ports/esp32$ make V=1
MicroPython v1.13-30-g1d344f446-dirty
Building with ESP IDF v4
LINK build-GENERIC_SPIRAM/bootloader.elf
xtensa-esp32-elf-gcc -nostdlib -L/home/xkp/esp32/esp-idf/lib -L/home/xkp/esp32/esp-idf/ld -u call_user_start_cpu0 -Wl,--gc-sections -static -Wl,-EL -Wl,-Map=build-GENERIC_SPIRAM/bootloader.map -Wl,--cref -T /home/xkp/esp32/esp-idf/components/bootloader/subproject/main/esp32.bootloader.ld -T /home/xkp/esp32/esp-idf/components/bootloader/subproject/main/esp32.bootloader.rom.ld -T /home/xkp/esp32/esp-idf/components/esp_rom/esp32/ld/esp32.rom.ld -T /home/xkp/esp32/esp-idf/components/esp_rom/esp32/ld/esp32.rom.newlib-funcs.ld -T /home/xkp/esp32/esp-idf/components/esp32/ld/esp32.peripherals.ld -o build-GENERIC_SPIRAM/bootloader.elf -Wl,--start-group -Lbuild-GENERIC_SPIRAM/bootloader -lbootloader_support -llog -lspi_flash -lsoc -lmain -L/home/xkp/esp32/esp-idf/components/esp_wifi/lib_esp32 -lrtc -L/home/xkp/esp32/xtensa-esp32-elf/bin/../lib/gcc/xtensa-esp32-elf/5.2.0/esp32-psram/ -lgcc -Wl,--end-group
/home/xkp/esp32/xtensa-esp32-elf/bin/../lib/gcc/xtensa-esp32-elf/5.2.0/../../../../xtensa-esp32-elf/bin/ld: cannot find -lrtc
collect2: error: ld returned 1 exit status
Makefile:979: recipe for target 'build-GENERIC_SPIRAM/bootloader.elf' failed
make: *** [build-GENERIC_SPIRAM/bootloader.elf] Error 1
Hope to get your help, thank you very much