`flash_<funcname>()` is implemented by `<funcname>_P()` provided by
the AVR libc on AVR targets. Previously, the preprocessor was used
to do the aliasing, but this causes issues with LLVM: The signatures of
e.g. `printf_P()` expects `const char *`, whereas flash utils expects
`FLASH_ATTR const char *`. For GCC this will just implicitly drop the
`FLASH_ATTR`, while it requires an explicit cast for LLVM.
To implement the explicit cast, `static inline` function wrappers
where used instead where possible. But for the variadic functions
(e.g. `printf(fmt, ...)`) the linker is used to provide the aliases,
as there is no way to pass the variadic functions throw in C. The
alternative would be to implement `flash_printf()` by calling
`vprintf_P()`, but that increased ROM size quite a bit.
Finally, a work around for a bug in Ubuntu's toolchain has been added:
An unused function that calls to `printf_P()`, `fprintf_P()` and
`snprintf_P()`. Since this function is garbage collected anyway, it
has no impact on the generated ELF file.
The current ISR implementation for AVR8 requires use of
avr8_[enter/exit]_isr pair which add some boilerplate on code.
This add AVR8_ISR which clean-up the code and make it simpler
and hides any schedule detail from the user perspective.
This is a preparation for future scheduling and irq optimizations.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
The thread_yield_higher is a normal functions. However it has a non
regular return instruction which is useless. This remove the useless
return on thread_yield_higher to save flash bytes.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
The avr8_state variable uses bit operation to set/clear the state. This
rework avr8_state to use increment/decrement instead. It introduce the
use of General Purpose IO Register 1 (GPIOR1) when available.
This is a preparation for future scheduling and irq optimizations.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
The avr8_state store state information used to determine scheduling
and uart irq. This move all uart irq states to avr8_state_uart
variable. It introduce the use of General Purpose IO Register 0
(GPIOR0) when available and now all uarts from xmega can be used.
This is a preparation for future scheduling and irq optimizations.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
This allows automatically moving format strings to flash, provided that
code previously compiled fine with `-Wformat-nonliteral` (which in RIOT
is the case due to `-Wformat=2`).
This adds a layer of convenience abstraction over classical Harvard
architectures (like most AVRs) that do not map the flash memory into
the data address space and modern Harvard architectures or von-Neumann
architectures that do so. The motivation is to safe a lot of RAM for
AVR by storing constant strings into flash.
18763: sys/tiny_strerror: add missing error codes r=benpicco a=maribu
### Contribution description
When double-checking the error codes provided by newlib by default (without magic defines, such as `__LINUX_ERRNO_EXTENSIONS__` or `__CYGWIN__`), some where still missing in `tiny_strerror()`. This adds the missing ones.
This in turn showed that three errno codes were missing in the avr-libc compat `errno.h`, which are added as well.
### Testing procedure
Murdock should double check that the added errno codes indeed are defined by default.
### Issues/PRs references
None
Co-authored-by: Marian Buschsieweke <marian.buschsieweke@ovgu.de>
The xfa.ld script is incompatible with binutils > 2.35.2 and results
in firmwares that wont boot. Sadly, I couldn't figure out an elegant
way to fix the issue. Instead, I modified the linker script provided
by binutils to also include XFA.
Add a minimal implementation of `strerror()`.
All other targets use either newlib or picolibc and provide this
function, add it to AVR so we can rely on it in common code.
Atmel AVR-8 CPU was reworked to accomodate variants like ATxmega.
This rename to atmega.inc.mk to avr8.inc.mk to be compliant with
new directory structure.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
ATxmega have many clock options. This introduce clk_init into cpu_init
to allow user select between a default configuration or perform fine
clock tune.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
The XMEGA CPU have a Programmable Multilevel Interrupt Controller.
This enables all three PMIC levels. By default, all interrupts are
preconfigured as LOW Level without Round Robin queue. This works
as any MCU with interrupt enabled.
In order to get benefit from Multilevel Interrupts user need increase
the interrupt level by own.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
Current there is no way to split code between ATmega and ATxmega in
drivers. This differentiate AVR8 cores into MEGAs and XMEGAs.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
The current context switch and thread stack init don't have a generic
way to save/restore registers for all AVR-8 variations. This add
defines to check flash/data sizes and rework:
- thread_stack_init
- avr8_context_save
- avr8_context_restore
The new implementation add missing RAMP D/X/Y registers that are used
by XMEGA variations.
The rules to add EIND, RAMP(D,X,Y,Z) register are:
- EIND must be added if device have more than 128k flash. This means,
device can access more than 64k words in flash.
- RAMP D/X/Y must be added if device have or can address more than
64k data.
- RAMPZ must be added if device can address more than 64k bytes of
flash or data.
With above rules there is no necessity to check by device because it is
mandatory the registers for those MCU variations.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
Some mega boards enabling global irq at board_init. This moves that
responsability to cpu/avr8_common to create a common point to all
variants.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
The ATxmega can have up to 8 UARTs. This increase from 2 up to 7 to
keep avr8_state flags with 8 bits wide.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
