Only with 1.02 the 24A racing kiss have a bootloader, so you have to upgrade it first.
They have a nice tutorial under http://kiss.flyduino.net/dwkb/how-to-flash-the-24a-race-edition-esc/ but works only under windows )=
The steps are similar instead of putty you can use cutecom:
if you use debian/ubuntu install it with:
sudo apt-get install cutecom
It should look like that:
After that download the 1.02 Firmware from http://ultraesc.de/hexGen/index.php with the serial number you read out from cutecom.
Because you need a binary file for flashing you have to convert it:
arm-none-eabi-objcopy -I ihex –output-target=binary KISS24A_1.02.hex KISS24A_1.02.bin
arm-none-eabi-objcopy comes with the arm toolchain you can install it with:
sudo apt-get install gcc-arm-none-eabi
After that you can flash your kiss 24A racing esc, be sure that the BT( bootloader solder jumper) is soldered than first unlock and flash it via stm32flash(Installation of stm32flash under linux is described here: https://wizneteu.wordpress.com/2015/03/19/flashing-stm32-via-serial-line-on-linux-stm32flash/comment-page-1/) :
stm32flash -k /dev/ttyUSB0
stm32flash -w KISS24A_1.02.bin /dev/ttyUSB0
desolder the BT jumper and restart the ESC, if it blinks shortly it looks good, be aware if you read with cutecom you get again the version 1.01 (Because 1.02 is the same version as 1.01 only with bootloader)
Have fun flashing, if anything is unclear feel free to post and ask
Sorry forget to mention, be aware you have to use a pl2302 or ftdi serial chipset, because there is a bug in the ch340 linux driver which caused that stm32flash was not working for me
enter
dmesg
after connecting your usb 2 serial converter and you should see which one you have