The compiler may generate calls to fminimum/fmaximum on some platforms.
Neither of the libm implementations we statically link against have these functions yet.
Implement them ourselves.
This changes the order for initialization of the random number
seed generation on wasm platforms until after the heap has been
initialized. Should fix#5198
Signed-off-by: deadprogram <ron@hybridgroup.com>
* machine/attiny85: add USI-based SPI support
Implement SPI communication for ATTiny85 using the USI (Universal Serial
Interface) hardware in three-wire mode. The ATTiny85 lacks dedicated SPI
hardware but can emulate SPI using the USI module with software clock
strobing.
Implementation details:
- Configure USI in three-wire mode for SPI operation
- Use clock strobing technique to shift data in/out
- Pin mapping: PB2 (SCK), PB1 (MOSI/DO), PB0 (MISO/DI)
- Support both Transfer() and Tx() methods
The implementation uses the USI control register (USICR) to toggle the
clock pin, which triggers automatic bit shifting in hardware. This is
more efficient than pure software bit-banging.
Current limitations:
- Frequency configuration not yet implemented (runs at max software speed)
- Only SPI Mode 0 (CPOL=0, CPHA=0) supported
- Only MSB-first bit order supported
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
Co-authored-by: Ona <no-reply@ona.com>
* machine/attiny85: add SPI frequency configuration support
Add software-based frequency control for USI SPI. The ATtiny85 USI lacks
hardware prescalers, so frequency is controlled via delay loops between
clock toggles.
- Calculate delay cycles based on requested frequency and CPU clock
- Fast path (no delay) when frequency is 0 or max speed requested
- Delay loop uses nop instructions for timing control
Co-authored-by: Ona <no-reply@ona.com>
* machine/attiny85: add SPI mode configuration support
Add support for all 4 SPI modes (Mode 0-3) using USI hardware:
- Mode 0 (CPOL=0, CPHA=0): Clock idle low, sample on rising edge
- Mode 1 (CPOL=0, CPHA=1): Clock idle low, sample on falling edge
- Mode 2 (CPOL=1, CPHA=0): Clock idle high, sample on falling edge
- Mode 3 (CPOL=1, CPHA=1): Clock idle high, sample on rising edge
CPOL is controlled by setting the clock pin idle state.
CPHA is controlled via the USICS0 bit in USICR.
Co-authored-by: Ona <no-reply@ona.com>
* machine/attiny85: add LSB-first bit order support
Add software-based LSB-first support for USI SPI. The USI hardware only
supports MSB-first, so bit reversal is done in software before sending
and after receiving.
Uses an efficient parallel bit swap algorithm (3 operations) to reverse
the byte.
Co-authored-by: Ona <no-reply@ona.com>
* GNUmakefile: add mcp3008 SPI example to digispark smoketest
Test the USI-based SPI implementation for ATtiny85/digispark.
Co-authored-by: Ona <no-reply@ona.com>
* machine/attiny85: minimize SPI RAM footprint
Reduce SPI struct from ~14 bytes to 1 byte to fit in ATtiny85's limited
512 bytes of RAM.
Changes:
- Remove register pointers (use avr.USIDR/USISR/USICR directly)
- Remove pin fields (USI pins are fixed: PB0/PB1/PB2)
- Remove CS pin management (user must handle CS)
- Remove frequency control (runs at max speed)
- Remove LSBFirst support
The SPI struct now only stores the USICR configuration byte.
Co-authored-by: Ona <no-reply@ona.com>
* Revert "machine/attiny85: minimize SPI RAM footprint"
This reverts commit 387ccad494.
Co-authored-by: Ona <no-reply@ona.com>
* machine/attiny85: reduce SPI RAM usage by 10 bytes
Remove unnecessary fields from SPI struct while keeping all functionality:
- Remove register pointers (use avr.USIDR/USISR/USICR directly)
- Remove pin fields (USI pins are fixed: PB0/PB1/PB2)
- Remove CS pin (user must manage it, standard practice)
Kept functional fields:
- delayCycles for frequency control
- usicrValue for SPI mode support
- lsbFirst for bit order support
SPI struct reduced from 14 bytes to 4 bytes.
Co-authored-by: Ona <no-reply@ona.com>
---------
Co-authored-by: Ona <no-reply@ona.com>
This simplifies the process of constructing and encoding layout bitmaps.
Instead of creating big integers and merging them, we can create a pre-sized bitmap and set positions within it.
This also changes the encoding logic to allow larger layouts to be encoded inline.
We would previously not encode a layout inline unless the size was less than the width of the data field.
This is overly conservative.
A layout can be encoded inline as long as:
1. The size fits within the size field.
2. All set bits in the bitmap fit into the data field.
* machine/attiny85: add PWM support for Timer0 and Timer1
Add complete PWM implementation for ATtiny85, supporting both Timer0
and Timer1 with their respective output channels:
- Timer0: 8-bit timer for pins PB0 (OC0A) and PB1 (OC0B)
- Timer1: 8-bit high-speed timer for pins PB1 (OC1A) and PB4 (OC1B)
Timer1 provides more flexible period control with configurable top value
(OCR1C) and extended prescaler options (1-16384), making it well-suited
for LED PWM control and other applications requiring variable frequencies.
Implements full PWM interface including Configure, SetPeriod, Channel,
Set, SetInverting, Top, Counter, and Period methods.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
* machine/digispark: document PWM support on pins
Add documentation to the Digispark board file indicating which pins
support PWM output:
- P0 (PB0): Timer0 channel A
- P1 (PB1): Timer0 channel B or Timer1 channel A
- P4 (PB4): Timer1 channel B
Includes package comment explaining Timer0 vs Timer1 capabilities,
with Timer1 recommended for more flexible frequency control.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
* machine/attiny85: optimize PWM prescaler lookups
Replace verbose switch statements with more efficient implementations:
- SetPeriod: Use bit shift (top >>= prescaler-1) instead of 15-case
switch for dividing uint64 by power-of-2 prescaler values
- Period: Replace switch statements with compact uint16 lookup tables
for both Timer0 and Timer1, casting to uint64 only when needed
This addresses review feedback about inefficient switch-based lookups.
On AVR, this approach is significantly smaller:
- Bit shifts for uint64 division: ~34 bytes vs ~140 bytes
- uint16 tables: 22 bytes code + 32/16 bytes data vs ~140 bytes
- Total savings: ~190 bytes (68% reduction)
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
* examples/pwm: add digispark support and smoketest
Add digispark.go configuration for PWM example using Timer1 with pins P1 (LED) and P4. Also add digispark PWM example to GNUmakefile smoketests.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
---------
Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>
* feat: Implement Lchown function for changing file ownership
- Added Lchown function to change the numeric uid and gid of a file or symbolic link.
- Included error handling to return *PathError for failed operations.
- Added unit tests for Lchown to verify behavior on different error scenarios.
* fix: fix chmod tests
Make timeoffset atomic to be able to handle changing the system
time. Otherwise the scheduler can gets rather confused if you call
AdjustTimeOffset when there are multiple goroutines already running.
Signed-off-by: deadprogram <ron@hybridgroup.com>
* - Fix SPI initialization by disabling interface before configuration.
- Ensure proper 8-bit configuration for STM32G0 SPI data register access.
- Add default pin initialization for SPI.
* Add Window Watchdog (WWDG) and ADC support for STM32G0
* Comment cleanup
* Refactored STM32G0 ADC sampling time configuration to use `switch` for improved readability
* Add STM32G0B1 target support
Introduce support for STM32G0B1 microcontrollers, including target-specific JSON files, linker scripts, and runtime initialization. This update adds hardware support for GPIO, UART, SPI, I2C, timers, and additional board-specific configurations like Nucleo-G0B1RE.
* Update STM32G0 clock initialization to 64MHz and adjust related configurations
Reconfigure STM32G0 to use a 64MHz system clock via PLL with HSI16 as the source. Update flash latency, prescaler settings, and I2C timing values to reflect the new frequency.
* Cleanup
* Cleanup
* Add STM32G0-specific UART implementation
Introduce a new UART implementation for the STM32G0 series with chip-specific setup and configuration methods. Update the generic STM32 UART code to exclude STM32G0.
* Refactor STM32G0 runtime and machine code to utilize chip-specific register access functions
Simplify and standardize register operations with dedicated setter methods in the STM32G0 runtime and machine code and cleanup redundant syntax.
* Remove redundant commented-out APBENR1 register operations in STM32G0 machine code
* Introduce FDCAN support for STM32G0B1 series
Add FDCAN peripheral implementation targeting STM32G0B1, including support for standard, extended identifiers, and bit rate configuration. Update board files to include FDCAN pins, instances, and clock configuration for Nucleo-G0B1RE and Amken Trio boards.
The GC bitmap length is measured in multiples of the pointer alignment.
This is equal to the pointer size on all architectures except AVR.
Replace the hardcoded lengths with lengths that are computed naturally.
The compiler now implements the copy builtin directly instead of calling sliceCopy.
The length is calculated with the llvm.umax.* intrinsics, and the move is performed by llvm.memmove.*.
Both of these operations are easily understood by LLVM's optimization passes.
The type's alignment is also provided to llvm.memmove.*, which is useful when rewriting the move.
Interp no longer needs to reimplement sliceCopy.
Some edge case handling was implemented by sliceCopy but not llvm.memmove.*/llvm.memcpy.*.
I copied this over, so copies of external slices should work now.
Volatile moves/copies are now run at runtime by interp.
There is a 4-byte size increase due to some confusing length logic in sendUSBPacket.
I will look at sendUSBPacket in a future PR.
This fixes two edge cases for min/max:
min/max(+0.0, -0.0) = -0.0, +0.0
min/max(number, NaN) = NaN, NaN
The compare and select method does not work here.
I switched to the llvm.minimum/llvm.maximum intrinsics which match the intended behavior.
The integer min/max were also swapped over to using intrinsics.
The compare and select path is now only used by strings.
Remove the sendUSBPacket maxLen param because this greatly confused the compiler.
It also fixes a bug where the length provided to the hardware may not match the length of the packet.
sendUSBPacket now panics if the sent packet is too big.
I also fixed some of the string descriptor logic where we could create a packet without fully populating it.
RP2* systems might require some more work since they are implemented very differently?
I don't have any of those to test with yet, so maybe someone can deal with them in a seperate PR?
The reason is that allocating without a heap is usually more visible
than using an uninitialized random generator which is subtle and may
lead to security vulnerabilities.
Based on suggestion from @eliasnaur
Signed-off-by: deadprogram <ron@hybridgroup.com>
Patricio Whittingslow
Micah Cowell
Nia Waldvogel
Dima Jolkin
deadprogram
Dima
Elias Naur
Matthew Hiles
Yaj
robo
Jesús Espino
Damian Gryski
Itxaka
Jake Bailey
Ayke van Laethem
Amken USA
gram
MakKi (makki_d)