fma - If the part is an STM32F103VBT, then the libmaple should work with some restrictions.
AFAIK, the Maple's 64 pin STM32F103RBT6 has the same set of peripherals (timers, UART, ADC, SPI, I2C, USB, etc.), at the same memory addresses as a 100 pin STM32F103VBT6 EXCEPT the STM32F103VBT6 has more digital I/O pins (GPIO).
The digital (GPIO) pins on the 100 pin STM32F103VBT6, compared to the 64 pin STM32F103RBT6, are additions to the existing port D, and an adds an extra port E. If you look at the Maple Native, which uses an STM32F103ZE, which is a 144 pin part, much of the work has been done.
The things to look for are wrapped in:
#ifdef STM32_HIGH_DENSITY
...
#endif
The Maple hasn't got enough digital pin names for the extra pins on port D. Maple does not have port E. However, these do exist on Maple Native. So you would need to understand a bit about how the ports work and then use the Maple Native code; it will need a new port structure for port E, and a pointer to the based address of the port peripheral, and define the right digital pins. You'll also need to create some sort of cross-reference so you can keep track of which pin names correspond to your board.
Maple Native uses a chip with more peripherals and memory than the STM32F103xB, so it might be better to either:
a) start with Maple's libmaple, and add in the GPIO from Maple Native (rather than start with Maple Native libmaple), or
b) start with Maple Native libmaple and remove the unique peripherals only available on Maple Native, and adjust the amount of memory available. (Edit: I wouldn't use this approach, I think it's much harder to get right. I was only mentioning this for completeness)
This *might* allow you to use the IDE, but I have never tried anything like this.
I think there may be a little bit of extra code depending on which peripherals, if any, override the GPIO pins.
(Full disclosure: I am not a member of LeafLabs staff.)
