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
 CRClibopencm3 STM32F2xx CRC
 CRYPTOlibopencm3 STM32F2xx Cryptographic controller
 DAClibopencm3 STM32F2xx DAC
 DMAlibopencm3 STM32F2xx DMA
 FLASHlibopencm3 STM32F2xx FLASH
 GPIOlibopencm3 STM32F2xx General Purpose I/O
 HASHlibopencm3 STM32F2xx Hash Processor
 I2Clibopencm3 STM32F2xx I2C
 IWDGlibopencm3 STM32F2xx Independent Watchdog Timer
 PWRlibopencm3 STM32F2xx Power Control
 RCClibopencm3 STM32F2xx Reset and Clock Control
 RTClibopencm3 STM32F2xx RTC
 SPIlibopencm3 STM32F2xx SPI
 Timerslibopencm3 STM32F2xx Timers
 USARTlibopencm3 STM32F2xx USART
 STM32F2xx DefinesDefined Constants and Types for the STM32F2xx series
 CRC Defineslibopencm3 Defined Constants and Types for the STM32F2xx CRC Generator
 CRYPTO DefinesDefined Constants and Types for the STM32F2xx CRYP Controller
 DAC DefinesDefined Constants and Types for the STM32F2xx DAC
 DMA DefinesDefined Constants and Types for the STM32F2xx DMA Controller
 EXTI DefinesDefined Constants and Types for the STM32F2xx External Interrupts
 FLASH DefinesDefined Constants and Types for the STM32F2xx FLASH Memory
 GPIO DefinesDefined Constants and Types for the STM32F2xx General Purpose I/O
 HASH DefinesDefined Constants and Types for the STM32F2xx HASH Controller
 I2C DefinesDefined Constants and Types for the STM32F2xx I2C
 IWDG DefinesDefined Constants and Types for the STM32F2xx Independent Watchdog Timer
 PWR DefinesDefined Constants and Types for the STM32F2xx PWR Control
 RCC DefinesDefined Constants and Types for the STM32F2xx Reset and Clock Control
 RTC DefinesDefined Constants and Types for the STM32F2xx RTC
 SPI DefinesDefined Constants and Types for the STM32F2xx SPI
 SYSCFG DefinesDefined Constants and Types for the STM32F2xx Sysconfig
 Timer Defineslibopencm3 Defined Constants and Types for the STM32F2xx Timers
 USART DefinesDefined Constants and Types for the STM32F2xx USART
 USB DefinesDefined Constants and Types for the STM32F* USB drivers
 Adc_defines
 ADC register base addresses
 ADC Channel Numbers
 ADC Number of channels in discontinuous mode.
 ADC watchdog channel
 ADC Number of channels in discontinuous injected mode
 Adc_file