In STM32F030 datasheet you can find that BOOT0 is the microcontroller pin, and BOOT1 is boot selector option bit (page 12)
In RM0360 on page 62 you can find that bit in FLASH_OBR register. There is also section about how to setup Boot configuration.
In the STM32F0x0, three different boot modes can be selected through the BOOT0 pin and boot configuration bits nBOOT1 in the User option byte, as shown in the following table.
(...)
The boot mode configuration is latched on the 4th rising edge of SYSCLK after a reset. It is up to the user to set boot mode configuration related to the required boot mode. The boot mode configuration is also re-sampled when exiting from Standby mode.