= STM32F105 =


The STM32F105, produced by ST Microelectronics, is part of the STM32F1 series of the lower end
CPUs with 64 to 256 kB FLASH and are thus best suited for real time control in industrial applications.

The STM32F105 BSP, based on the STM32F4 BSP, is compiled according to 
http://alanstechnotes.blogspot.fr/2013/03/setting-up-rtems-development.html. We use the RTEMS toolchain
builder from source with

{{{
  ../source-builder/sb-set-builder --log=build-log.txt --prefix=$HOME/prefix/compiler/4.11 4.11/rtems-arm
}}}

Having compiled the toolchain, RTEMS is compiled for the STM32F105 BSP following
http://s937484.blogspot.fr/2013/10/rtems-stm32f407-discovery-board-posted.html: RTEMS is compiled with

{{{
  export PATH=$HOME/prefix/compiler/4.11/bin:$PATH
  export TARGET="arm-rtems4.11"
  ./bootstrap 
}}}

in the RTEMS directory and then in the build directory:

{{{
  ../rtems/configure --target=${TARGET} --enable-rtemsbsp=stm32f105rc --enable-tests=samples --prefix=$HOME/prefix/rtems-4.11
  make
  make install
}}}

We run the example from the testsuit c/stm32f105rc/testsuites/samples/hello on Qemu supporting the STM32 architecture as described at: https://github.com/beckus/qemu_stm32

The trick is that, as indicated at ftp://ftp.rtems.eu/pub/rrr/RRR_Quick_Start_Guide_en.pdf, the
console is connected to UART3. Qemu as found on the previous GIT site only implements UART2: the two options
are either to add support for UART3 to Qemu, or to move the console to another serial port. The former
solution is easiest, the latter most useful for practical applications on real board which might use other
UARTs than UART3. For modifying Qemu, edit hw/arm/stm32_p103.c in the Qemu source tree downloaded from 
the github site and add both UART1 and UART3 by including


{{{
    DeviceState *uart1 = DEVICE(object_resolve_path("/machine/stm32/uart[1]", NULL));
    DeviceState *uart3 = DEVICE(object_resolve_path("/machine/stm32/uart[3]", NULL));
    assert(uart1);
    assert(uart3);
    stm32_uart_connect((Stm32Uart *)uart1,serial_hds[0],STM32_USART1_NO_REMAP);
    stm32_uart_connect((Stm32Uart *)uart3,serial_hds[2],STM32_USART3_NO_REMAP);
}}}

The latest revision of the two files located in the hw/arm directory of QEmu for STM32 and compatible
with running RTEMS are available at http://jmfriedt.free.fr/stm32_p103.c and http://jmfriedt.free.fr/stm32.c.
Having compiled Qemu with these updates, and RTEMS for the STM32F105 BSP, the example is loaded using

{{{
    qemu-system-arm -M stm32-p103 -serial stdio -serial stdio -serial stdio -kernel hello.bin
}}}

(three times -serial stdio to indicate that all three UART outputs are displayed on stdout). The result is
{{{
    VNC server running on `::1:5900'
    LED Off
    *** BEGIN OF TEST HELLO WORLD ***
    Hello World
    *** END OF TEST HELLO WORLD ***
}}}

For modifying the default UART used by the console, either edit the RTEMS BSP defined in the rtems/c/src/lib/libbsp/arm/stm32f4/configure.ac file and modify {{{RTEMS_BSPOPTS_SET([STM32F4_ENABLE_USART_3],[*],[1])}}} for disabling UART3 (remove [1] and replace with []) and activating UART1 (replace [] with [1]). Alternatively, before
the configuration step, export variables {{{STM32F4_ENABLE_USART_3=""}}} and {{{STM32F4_ENABLE_USART_1="1"}}} for the same
effect. Following this modification, the hello.exe example was run successfuly on a STM32F103RCT microcontroller.

Notice that at the moment, the STM32 support for QEmu does not include (yet) the A/D converters: requesting a sample with a loop testing the conversion completion will hang since the conversion never occurs.