libopencm3
A free/libre/open-source firmware library for various ARM Cortex-M3 microcontrollers.
STM32F2
Here is a list of all modules:
[detail level 123]
 STM32F2xxLibraries for ST Microelectronics STM32F2xx series
 GPIOlibopencm3 STM32F2xx General Purpose I/O
 RCClibopencm3 STM32F2xx Reset and Clock Control
 STM32F2xx DefinesDefined Constants and Types for the STM32F2xx series
 RTC DefinesDefined Constants and Types for the STM32F2xx RTC
 CRC Defineslibopencm3 Defined Constants and Types for the STM32F2xx CRC Generator
 DMA DefinesDefined Constants and Types for the STM32F2xx DMA Controller
 SPI DefinesDefined Constants and Types for the STM32F2xx SPI
 RCC DefinesDefined Constants and Types for the STM32F2xx Reset and Clock Control
 USART DefinesDefined Constants and Types for the STM32F2xx USART
 PWR DefinesDefined Constants and Types for the STM32F2xx PWR Control
 CRYPTO DefinesDefined Constants and Types for the STM32F2xx CRYP Controller
 HASH DefinesDefined Constants and Types for the STM32F2xx HASH Controller
 FLASH DefinesDefined Constants and Types for the STM32F2xx FLASH Memory
 IWDG DefinesDefined Constants and Types for the STM32F2xx Independent Watchdog Timer
 EXTI DefinesDefined Constants and Types for the STM32F2xx External Interrupts
 DAC DefinesDefined Constants and Types for the STM32F2xx DAC
 Timer Defineslibopencm3 Defined Constants and Types for the STM32F2xx Timers
 I2C DefinesDefined Constants and Types for the STM32F2xx I2C
 GPIO DefinesDefined Constants and Types for the STM32F2xx General Purpose I/O
 SYSCFG DefinesDefined Constants and Types for the STM32F2xx Sysconfig
 User interrupt service routines (ISR) prototypes for STM32 F2 series
 DebuggingMacros and functions to aid in debugging
 NVIC Defineslibopencm3 Cortex Nested Vectored Interrupt Controller
 User interrupts for STM32 F2 series
 Cortex M0/M3/M4 System InterruptsIRQ numbers -3 and -6 to -9 are reserved
 SysTick Defineslibopencm3 Defined Constants and Types for the Cortex SysTick
 Clock source selection
 USB MSC Type DefinitionsDefined Constants and Types for the USB MSC Type Definitions
 USB DriversDefined Constants and Types for the USB Drivers
 USB Standard Structure DefinitionsDefined Constants and Types for the USB Standard Structure Definitions
 User interrupt service routines (ISR) defaults for STM32 F2 series
 NVIClibopencm3 Cortex Nested Vectored Interrupt Controller
 SysTicklibopencm3 Cortex System Tick Timer
 Generic USB DriversGeneric USB Drivers
 Generic USB Control RequestsGeneric USB Control Requests
 Generic USB Standard Request InterfaceGeneric USB Standard Request Interface
 Rng_fileThis library supports the random number generator peripheral (RNG) in the STM32F4 series of ARM Cortex Microcontrollers by ST Microelectronics
 Crc_file
 Crypto_filelibopencm3 STM32 Cryptographic controller
 Dac_file
 Dma_file
 Flash_file
 Hash_file
 I2c_file
 Iwdg_file
 Rtc_file
 Spi_file
 Timer_file
 Usart_file
 Usb_msc