boards: tt_blackhole: only write vars.cfg when kconfig exists

When building the app/smc target with --sysbuild, then output
file is written 3 times. At least the last of those times,
CONFIG_TT_SRST_ASSIST is unset, which only means the first
line is written to the file.

Only write bmc-reset-vars.cfg when CONFIG_TT_SRST_ASSIST is
defined so that the file is fully populated.

Signed-off-by: Chris Friedt <[email protected]>

Author: cfriedt

boards/tenstorrent/tt_blackhole/board.cmake

@@ -14,16 +14,16 @@ if(CONFIG_ARM)
   board_runner_args(stm32cubeprogrammer "--port=swd" "--reset-mode=hw")
 endif()
 
-set(BMC_VARS "# Autogenerated file with variables to reset SMC. Don't edit!\n")
 if(CONFIG_TT_SRST_ASSIST)
+  set(BMC_VARS "# Autogenerated file with variables to reset SMC. Don't edit!\n")
   string(APPEND BMC_VARS "set OPENOCD ${OPENOCD}\n")
   string(APPEND BMC_VARS "set OPENOCD_DEFAULT_PATH ${OPENOCD_DEFAULT_PATH}\n")
   string(APPEND BMC_VARS "set BMC_CFG ${CMAKE_CURRENT_LIST_DIR}/support/tt_blackhole_bmc.cfg\n")
   string(APPEND BMC_VARS "set RST_GPIO_REG ${CONFIG_TT_SRST_ASSIST_ADDR}\n")
   string(APPEND BMC_VARS "set RST_GPIO_SET_MASK ${CONFIG_TT_SRST_ASSIST_SET}\n")
   string(APPEND BMC_VARS "set RST_GPIO_CLR_MASK ${CONFIG_TT_SRST_ASSIST_CLR}\n")
+  file(WRITE ${CMAKE_CURRENT_LIST_DIR}/support/bmc-reset-vars.cfg ${BMC_VARS})
 endif()
-file(WRITE ${CMAKE_CURRENT_LIST_DIR}/support/bmc-reset-vars.cfg ${BMC_VARS})
 
 # Include debugger templates below (order is important)
 include(${ZEPHYR_BASE}/boards/common/openocd.board.cmake)