I've attached 2 files to add some basic flash things.
This would allow to use higher frequencies with the stm32.
The following code push my stm32 with an external 16MHz oscillator to
/* enable Internal High Speed Oscillator */
/* Select HSI as SYSCLK source. */
/* enable External High Speed Oscillator */
/* set prescalers for ADC, ABP1, ABP2 */
/* should run with 72MHz -> 2 Waitstates */
/* Set the PLL multiplication factor to 9. -> 16MHz (external) *
9 (Multiplikator) / 2 (PLLXTPRE) = 72MHz */
/* Select HSE as PLL source. */
/* divide external frequency by 2 before entering pll */
/* Enable PLL oscillator and wait for it to stabilize. */
/* Select PLL as SYSCLK source. */