This release contains numerous bug fixes and documentation improvements. Additionally, it contains the following notable changes/improvements:

Updated TinyUSB to 0.12.0

• The lib/tinyusb submodule has been updated from 0.10.1 to 0.12.0. See https://github.com/hathach/tinyusb/releases/tag/0.11.0 and https://github.com/hathach/tinyusb/releases/tag/0.12.0 for release notes.
• Improvements have been made for projects that include TinyUSB and also compile with enhanced warning levels and -Werror. Warnings have been fixed in rp2040 specific TinyUSB code, and in TinyUSB headers, and a new cmake function suppress_tinyusb_warnings() has been added, that you may call from your CMakeLists.txt to suppress warnings in other TinyUSB C files.

New Board Support

The following boards have been added and may be specified via PICO_BOARD:

• adafruit_trinkey_qt2040
• melopero_shake_rp2040
• pimoroni_interstate75
• pimoroni_plasma2040
• pybstick26_rp2040
• waveshare_rp2040_lcd_0.96
• waveshare_rp2040_plus_4mb
• waveshare_rp2040_plus_16mb
• waveshare_rp2040_zero

Updated SVD, hardware_regs, hardware_structs

The RP2040 SVD has been updated, fixing some register access types and adding new documentation.

The hardware_regs headers have been updated accordingly.

The hardware_structs headers which were previously hand coded, are now generated from the SVD, and retain select documentation from the SVD, including register descriptions and register bit-field tables.

e.g. what was once

typedef struct {
    io_rw_32 ctrl;
    io_ro_32 fstat;
    ...

becomes:

// Reference to datasheet: https://datasheets.raspberrypi.com/rp2040/rp2040-datasheet.pdf#tab-registerlist_pio
//
// The _REG_ macro is intended to help make the register navigable in your IDE (for example, using the "Go to Definition" feature)
// _REG_(x) will link to the corresponding register in hardware/regs/pio.h.
//
// Bit-field descriptions are of the form:
// BITMASK [BITRANGE]: FIELDNAME (RESETVALUE): DESCRIPTION

typedef struct {
    _REG_(PIO_CTRL_OFFSET) // PIO_CTRL
    // PIO control register
    // 0x00000f00 [11:8]  : CLKDIV_RESTART (0): Restart a state machine's clock divider from an initial phase of 0
    // 0x000000f0 [7:4]   : SM_RESTART (0): Write 1 to instantly clear internal SM state which may be otherwise difficult...
    // 0x0000000f [3:0]   : SM_ENABLE (0): Enable/disable each of the four state machines by writing 1/0 to each of these four bits
    io_rw_32 ctrl;

    _REG_(PIO_FSTAT_OFFSET) // PIO_FSTAT
    // FIFO status register
    // 0x0f000000 [27:24] : TXEMPTY (0xf): State machine TX FIFO is empty
    // 0x000f0000 [19:16] : TXFULL (0): State machine TX FIFO is full
    // 0x00000f00 [11:8]  : RXEMPTY (0xf): State machine RX FIFO is empty
    // 0x0000000f [3:0]   : RXFULL (0): State machine RX FIFO is full
    io_ro_32 fstat;
    ...

Behavioral Changes

There were some behavioral changes in this release:

pico_sync

SDK 1.2.0 previously added recursive mutex support using the existing (previously non-recursive) mutex_ functions. This caused a performance regression, and the only clean way to fix the problem was to return the mutex_ functions to their pre-SDK 1.2.0 behavior, and split the recursive mutex functionality out into separate recursive_mutex_ functions with a separate recursive_mutex_ type.

Code using the SDK 1.2.0 recursive mutex functionality will need to be changed to use the new type and functions, however as a convenience, the pre-processor define PICO_MUTEX_ENABLE_SDK120_COMPATIBILITY may be set to 1 to retain the SDK 1.2.0 behavior at the cost of an additional performance penalty. The ability to use this pre-processor define will be removed in a subsequent SDK version.

pico_platform

• pico.h and its dependencies have been slightly refactored so it can be included by assembler code as well as C/C++ code. Thie ensures that assembler code and C/C++ code follow the same board configuration/override order and see the same configuration defines. This should not break any existing code, but is notable enough to mention.
• pico/platform.h is now fully documented.

pico_standard_link

-Wl,max-page-size=4096 is now passed to the linker, which is beneficial to certain users and should have no discernible impact on the rest.

Other Notable Improvements

hardware_base

• Added xip_noalloc_alias(addr), xip_nocache_alias(addr), xip_nocache_noalloc_alias(addr) macros for converting a flash address between XIP aliases (similar to the hw_xxx_alias(addr) macros).

hardware_dma

• Added dma_timer_claim(), dma_timer_unclaim(), dma_claim_unused_timer() and dma_timer_is_claimed() to manage ownership of DMA timers.
• Added dma_timer_set_fraction() and dma_get_timer_dreq() to facilitate pacing DMA transfers using DMA timers.

hardware_i2c

• Added i2c_get_dreq() function to facilitate configuring DMA transfers to/from an I2C instance.

hardware_irq

• Added irq_get_priority().
• Fixed implementation when PICO_DISABLE_SHARED_IRQ_HANDLERS=1 is specified, and allowed irq_add_shared_handler to be used in this case (as long as there is only one handler - i.e. it behaves exactly like irq_set_exclusive_handler),
• Sped up IRQ priority initialization which was slowing down per core initialization.

hardware_pio

• pio_encode_ functions in hardware/pico_instructions.h are now documented.

hardware_pwm

• Added pwm_get_dreq() function to facilitate configuring DMA transfers to a PWM slice.

hardware_spi

• Added spi_get_dreq() function to facilitate configuring DMA transfers to/from an SPI instance.

hardware_uart

• Added uart_get_dreq() function to facilitate configuring DMA transfers to/from a UART instance.

hardware_watchdog

• Added watchdog_enable_caused_reboot() to distinguish a watchdog reboot caused by a watchdog timeout after calling watchdog_enable() from other watchdog reboots (e.g. that are performed when a UF2 is dragged onto a device in BOOTSEL mode).

pico_bootrom

• Added new constants and function signature typedefs to pico/bootrom.h to facilitate calling bootrom functions directly.

pico_multicore

• Improved documentation in pico/multicore.h; particularly, multicore_lockout_ functions are newly documented.

pico_platform

• PICO_RP2040 is now defined to 1 in PICO_PLATFORM=rp2040 (i.e. normal) builds.

pico_stdio

• Added puts_raw() and putchar_raw() to skip CR/LF translation if enabled.
• Added stdio_usb_connected() to detect CDC connection when using stdio_usb.
• Added PICO_STDIO_USB_CONNECT_WAIT_TIMEOUT_MS define that can be set to wait for a CDC connection to be established during initialization of stdio_usb. Note: value -1 means indefinite. This can be used to prevent initial program output being lost, at the cost of requiring an active CDC connection.
• Fixed semihosting_putc which was completely broken.

pico_usb_reset_interface

• This new library contains pico/usb_reset_interface.h split out from stdio_usb to facilitate inclusion in external projects.

CMake build

• OUTPUT_NAME target property is now respected when generating supplemental files (.BIN, .HEX, .MAP, .UF2)

pioasm

• Operator precedence of *, /, -, + have been fixed
• Incorrect MicroPython output has been fixed.

elf2uf2

• A bug causing an error with binaries produces by certain other languages has been fixed.