Hmm, they haven't pulled it yet but look at
https://github.com/ChuckM/libopencm3-examples
Which has blink_tick in it. But that said, I did get it to build (using the
arm-none-eabi- toolchain from ARM Ltd)
I got stuck trying to figure out how I'd template the STM32F4-Discovery
board though. The docs on that are a bit thin :-) And then I got distracted
seeing if I could get the MSP430 working (which apparently I've got old
firmware on my launchpad board so that was a no go). Way to easily
distracted I think.
We can take this off list I suspect its not exactly interesting to others
here.
--Chuck
On Wed, Oct 9, 2013 at 5:02 PM, Paul Sokolovsky <[email protected]> wrote:
> Hello,
>
> On Wed, 9 Oct 2013 15:41:41 -0700
> Chuck McManis <[email protected]> wrote:
>
> > Interesting library,
>
> Thanks.
>
> > I noticed it has 'blink tick' below: Can you
> > compare the chunk sizes of that on the STM32 with the one that is in
> > libopencm3-examples ? (I pulled a copy of the repo but I've got some
> > missing dependencies to work on before I can do this test)
>
> Which one of libopencm3-examples you'd like to compare exactly?
> blink_tick implements RTOS-like (or Arduino-like if you prefer) delay
> waiting: OS has "ticks" variable, and you do all time handling
> using it. I didn't see something like that in libopencm3-examples. If
> you mean systick.c, which toggles LED in IRQ handler, then closest
> would be irq_dispatch_simple.cpp.
>
> Built with default -Os (stm32/f1/other/systick/):
> $ arm-none-eabi-size systick.o systick.elf
> text data bss dec hex filename
> 136 0 4 140 8c systick.o
> 1328 8 4 1340 53c systick.elf
>
>
> It makes little sense to build PTL with -Os, GCC (at least pretty
> ancient Sourcery G++ Lite 2010.09-51) 4.5.1) misses a lot when to do
> inlining and when not:
>
> -Os
> $ arm-none-eabi-size irq_dispatch_simple.o irq_dispatch_simple
> text data bss dec hex filename
> 146 0 0 146 92 irq_dispatch_simple.o
> 302 0 0 302 12e irq_dispatch_simple
>
> -O2 gets it right:
> $ arm-none-eabi-size irq_dispatch_simple.o irq_dispatch_simple
> text data bss dec hex filename
> 116 0 0 116 74 irq_dispatch_simple.o
> 252 0 0 252 fc irq_dispatch_simple
>
> Note also that irq_dispatch_simple doesn't do any counter checks in IRQ
> handler.
>
>
> For comparison, systick -O2:
> $ arm-none-eabi-size systick.o systick.elf
> text data bss dec hex filename
> 164 0 4 168 a8 systick.o
> 1356 8 4 1368 558 systick.elf
>
>
> Full binary sizes are kinda for completeness, they can't be compared
> one to one: PTL's includes just Cortex-M core IRQs and doesn't init
> crystals/PLLs. PTL is a research proof of concept library, not really
> suitable for developing USB gadgets yet ;-). On the other hand,
> irq_dispatch_simple is even more magic than it seems. You can't really
> abstract IRQ handling across MCUs while retaining asm-like efficiency.
> At least that was my presupposition. And yet irq_dispatch_simple runs
> on both MSP430 and ARM with the same source and with decent resulting
> asm. Hand-rewriting might save couple of bytes and couple of cycles, but
> that's about it.
>
> []
>
> >
> >
> > On Wed, Oct 9, 2013 at 1:03 PM, Paul Sokolovsky <[email protected]>
> > wrote:
> >
> > > Hello,
> > >
> > > On Wed, 9 Oct 2013 12:06:18 -0500
> > > Linge Dai <[email protected]> wrote:
> > >
> > > > Hi,
> > > >
> > > > I'm using STM32F4 + libopencm3. I have noticed that some of the
> > > > library functions are declared to have a pointer to registers as a
> > > > parameter:
> > > >
> > > > For example, in rcc.h:
> > > > void rcc_peripheral_enable_clock(volatile uint32_t *reg, uint32_t
> > > > en);
> > > >
> > > > which allows modifying any arbitrary register. The programmers
> > > > need to explicitly enforce restrictions on what to pass to the
> > > > function. Is the API meant to be designed this way?
> > > >
> > > > A fix to this problem is to wrap the valid register values in an
> > > > enum and use the enum as the function parameter. The new
> > > > declaration of this function will be:
> > > >
> > > > void rcc_peripheral_enable_clock(clock_enable_reg_t
> > > > clock_enable_reg, uint32_t en);
> > >
> > > Would it change *that* much? There still will be a function which
> > > needs to be called, do the dynamic bit manipulation and return.
> > > Shouldn't it be something like:
> > >
> > > peripheral_enable_clock<clock_enable_reg_t, uint32_t>() to emphasize
> > > that it should be compile-time constants?
> > >
> > > Actually, shouldn't it be Block::clk_foo::enable() ?
> > >
> > > Shameless plug: https://github.com/pfalcon/PeripheralTemplateLibrary
> > > tries to do exactly that, providing efficient abstraction of MCU
> > > blocks and algorithms. Already has something to show off across
> > > AVR, MSP430 & Cortex-M.
> > >
> > >
> > > --
> > > Best regards,
> > > Paul mailto:[email protected]
> > >
> > >
> > >
> ------------------------------------------------------------------------------
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> > > _______________________________________________ libopencm3-devel
> > > mailing list [email protected]
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> > >
>
>
>
> --
> Best regards,
> Paul mailto:[email protected]
>
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