RP2350 (Pico 2) port — Milestone 1: Build system & empty target

[sensei-hacker]

User description

Summary

Establish the CMake build system for RP2350 (Raspberry Pi Pico 2) so that make RP2350_PICO produces a linked ARM ELF binary. This is Milestone 1 of the RP2350 port — the binary uses stubs for all hardware interaction.

Changes

New platform files (9 files):

• cmake/cortex-m33.cmake — Cortex-M33 CPU architecture flags
• cmake/rp2350.cmake — Platform module with target_rp2350() function
• src/main/target/RP2350_PICO/ — Board definition, system stubs, config
• src/main/target/link/rp2350_flash.ld — Linker script (4MB flash, 512KB RAM)
• src/main/startup/startup_rp2350.s — Minimal Cortex-M33 startup
• src/main/startup/boot2_rp2350.S — 256-byte boot2 stage 2 stub

Modified existing files (14 files):

• Added RP2350 guards alongside SITL_BUILD exclusions for hardware-specific code (EXTI, PWM, ADC, atomic, timer, IO, CLI, fc_init)
• Added include(rp2350) to root CMakeLists.txt
• Added RP2350 block to platform.h

Submodule:

• Pico SDK 2.1.0 at lib/main/pico-sdk (headers only for M1)

Build Output

• 694KB text, 9KB data, 95KB BSS
• ARM ELF32, hard-float ABI, entry point in XIP flash region
• .hex output generated

Test plan

• make RP2350_PICO compiles and links successfully
• Verify existing STM32/AT32/SITL targets unaffected (CI)
• Future milestones: real hardware init, sensor drivers, motor output

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PR Type

New Target

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Description

This description is generated by an AI tool. It may have inaccuracies

• Establish CMake build system for RP2350 (Pico 2) with Cortex-M33 support

• Add platform configuration files: linker script, startup assembly, boot2 stub

• Create RP2350_PICO target with hardware stubs for all drivers

• Guard existing hardware-specific code paths with RP2350 exclusions

• Integrate Pico SDK 2.1.0 as submodule for headers

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Diagram Walkthrough

flowchart LR
  A["CMake Build System"] --> B["Cortex-M33 Config"]
  A --> C["RP2350 Platform Module"]
  C --> D["Linker Script"]
  C --> E["Startup Assembly"]
  C --> F["Boot2 Stage 2"]
  C --> G["Target Definition"]
  G --> H["Hardware Stubs"]
  H --> I["Drivers & System"]
  J["Pico SDK 2.1.0"] --> K["Headers Only"]
  L["Existing Code"] --> M["RP2350 Guards"]
  M --> N["EXTI, PWM, ADC, Timer, IO"]
  A --> O["Linked ARM ELF Binary"]

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File Walkthrough

	Relevant files
Configuration changes	5 files cortex-m33.cmake Cortex-M33 CPU architecture compiler flags                              +23/-0    rp2350.cmake RP2350 platform CMake module with target function                +181/-0  rp2350_flash.ld Linker script for 4MB flash and 512KB RAM layout                  +190/-0  CMakeLists.txt CMake target invocation for RP2350_PICO build                        +1/-0      CMakeLists.txt Include RP2350 CMake platform module                                          +1/-0
New feature	5 files startup_rp2350.s Minimal Cortex-M33 startup assembly with vector table        +288/-0  boot2_rp2350.S 256-byte boot2 stage 2 bootloader stub                                      +29/-0    target.h Target board definitions and dummy type stubs                        +163/-0  target.c Hardware stubs for system, timer, PWM, UART, DSP                  +225/-0  config.c Target configuration function placeholder                                +25/-0
Enhancement	2 files platform.h Add RP2350 platform header block with U_ID                              +7/-0      config_streamer_ram.c Add common/utils.h include for RP2350 support                        +1/-0
Bug fix	11 files accgyro.c Guard atomic.h include with RP2350 exclusion                          +1/-1      adc.c Guard ADC driver implementation with RP2350 exclusion        +1/-1      exti.c Guard EXTI driver with RP2350 exclusion                                    +1/-1      io.c Add RP2350 case to IO_EXTI_Line function                                  +1/-1      io.h Add RP2350 to IO configuration macro guards                            +1/-1      pwm_mapping.c Guard PWM mapping with RP2350 exclusion                                    +1/-1      pwm_output.c Guard PWM output driver with RP2350 exclusion                        +1/-1      timer.h Add RP2350 timer type definitions and count                            +7/-0      timer_def.h Add RP2350 case to timer definition includes                          +1/-0      cli.c Guard CLI status output with RP2350 exclusion                        +4/-4      fc_init.c Guard hardware initialization with RP2350 exclusion            +6/-4
Dependencies	2 files .gitmodules Add Pico SDK 2.1.0 as git submodule                                            +3/-0      pico-sdk Pico SDK 2.1.0 submodule reference                                              +1/-0

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[qodo-code-review]

PR Compliance Guide 🔍

Below is a summary of compliance checks for this PR:

Security Compliance
⚪	Non-unique device ID Description: U_ID_0/U_ID_1/U_ID_2 are hardcoded to constant values for RP2350, which can break any code that assumes these are per-device unique identifiers (e.g., deriving serial numbers, keys, or binding tokens), potentially enabling device-impersonation or collisions if used for authentication/anti-cloning features. platform.h [81-87] Referred Code #elif defined(RP2350) // RP2350 (Raspberry Pi Pico 2) - Cortex-M33 // Platform headers provided by target.h dummy types #define U_ID_0 0 #define U_ID_1 1 #define U_ID_2 2
Ticket Compliance
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Codebase Duplication Compliance
⚪	Codebase context is not defined Follow the guide to enable codebase context checks.
Custom Compliance
🟢	Generic: Comprehensive Audit Trails Objective: To create a detailed and reliable record of critical system actions for security analysis and compliance. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Meaningful Naming and Self-Documenting Code Objective: Ensure all identifiers clearly express their purpose and intent, making code self-documenting Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Robust Error Handling and Edge Case Management Objective: Ensure comprehensive error handling that provides meaningful context and graceful degradation Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Secure Error Handling Objective: To prevent the leakage of sensitive system information through error messages while providing sufficient detail for internal debugging. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Secure Logging Practices Objective: To ensure logs are useful for debugging and auditing without exposing sensitive information like PII, PHI, or cardholder data. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Security-First Input Validation and Data Handling Objective: Ensure all data inputs are validated, sanitized, and handled securely to prevent vulnerabilities Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
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⚪ - Requires Further Human Verification
🏷️ - Compliance label

[qodo-code-review]

PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Impact
High-level	✅ Re-evaluate the CMSIS-DSP stubbing strategy Suggestion Impact: The commit removes the CMSIS-DSP stub implementations from src/main/target/RP2350_PICO/target.c and drops the arm_math.h include, aligning with the suggestion to stop stubbing CMSIS-DSP functions in target.c (though no corresponding CMake/ifdef strategy change is shown in this patch). code diff: -#include "arm_math.h" +#include "drivers/serial_uart_impl.h" -const int timerHardwareCount = 0; -timerHardware_t timerHardware[1]; -uint32_t SystemCoreClock = 150000000; // 150 MHz RP2350 - -// Called from startup_rp2350.s (uppercase) -void SystemInit(void) { } - -void systemInit(void) -{ - // Stub - M1 does nothing -} - -timeUs_t micros(void) -{ - return 0; // Stub -} - -uint64_t microsISR(void) -{ - return 0; // Stub -} - -uint32_t millis(void) -{ - return 0; // Stub -} - -void delayMicroseconds(timeUs_t us) -{ - UNUSED(us); -} - -void delay(timeMs_t ms) -{ - UNUSED(ms); -} - -void systemReset(void) -{ - while (1) {} -} - -void systemResetToBootloader(void) -{ - while (1) {} -} +/* + * Output mapping table — 8 GPIO pins in 4 slice groups. + * + * All entries use TIM_USE_OUTPUT_AUTO so pwmMotorAndServoInit() assigns + * them as motors or servos based on getMotorCount() and any + * timerOverrides() the user has set in the Configurator. + * + * Field order matches timerHardware_t (non-AT32 build): + * tim, tag, channelIndex, output, ioMode, alternateFunction, usageFlags, dmaTag + * + * Port A (gpioid 0) = GPIO 0–15; Port B (gpioid 1) = GPIO 16–29. + * GP8 = PA8 GP9 = PA9 GP10 = PA10 GP11 = PA11 + * GP16 = PB0 GP17 = PB1 GP18 = PB2 GP19 = PB3 + */ +timerHardware_t timerHardware[] = { + /* slice 4 — motor group 1 */ + DEF_TIM(TIM4, CH1, PA8, TIM_USE_OUTPUT_AUTO, 0, 0), /* GP8 */ + DEF_TIM(TIM4, CH2, PA9, TIM_USE_OUTPUT_AUTO, 0, 0), /* GP9 */ + /* slice 5 — motor group 2 */ + DEF_TIM(TIM5, CH1, PA10, TIM_USE_OUTPUT_AUTO, 0, 0), /* GP10 */ + DEF_TIM(TIM5, CH2, PA11, TIM_USE_OUTPUT_AUTO, 0, 0), /* GP11 */ + /* slice 8 — flexible group 1 */ + DEF_TIM(TIM8, CH1, PB0, TIM_USE_OUTPUT_AUTO, 0, 0), /* GP16 */ + DEF_TIM(TIM8, CH2, PB1, TIM_USE_OUTPUT_AUTO, 0, 0), /* GP17 */ + /* slice 9 — flexible group 2 */ + DEF_TIM(TIM9, CH1, PB2, TIM_USE_OUTPUT_AUTO, 0, 0), /* GP18 */ + DEF_TIM(TIM9, CH2, PB3, TIM_USE_OUTPUT_AUTO, 0, 0), /* GP19 */ +}; +const int timerHardwareCount = 8; void failureMode(failureMode_e mode) { @@ -91,136 +75,24 @@ while (1) {} } -uint32_t getEscUpdateFrequency(void) -{ - return 400; -} - -pwmInitError_e getPwmInitError(void) -{ - return PWM_INIT_ERROR_NONE; -} - -const char *getPwmInitErrorMessage(void) -{ - return "No error"; -} - -void IOConfigGPIO(IO_t io, ioConfig_t cfg) -{ - UNUSED(io); - UNUSED(cfg); -} - -void timerInit(void) -{ - // NOP -} - bool isMPUSoftReset(void) { return false; } -// PWM output stubs (pwm_output.c is guarded out for RP2350) -void pwmWriteMotor(uint8_t index, uint16_t value) -{ - UNUSED(index); - UNUSED(value); -} - -void pwmShutdownPulsesForAllMotors(uint8_t motorCount) -{ - UNUSED(motorCount); -} - -void pwmWriteServo(uint8_t index, uint16_t value) -{ - UNUSED(index); - UNUSED(value); -} - -// Timer stub (timer.c is excluded from build) -uint8_t timer2id(const HAL_Timer_t *tim) -{ - UNUSED(tim); - return 0; -} - -// UART stub (no UART driver for RP2350 M1) +// UART dispatch — hardware UARTs 1-2 via RP2350 PL011, PIO UARTs 3-4 via PIO1 serialPort_t *uartOpen(USART_TypeDef *USARTx, serialReceiveCallbackPtr rxCallback, void *rxCallbackData, uint32_t baudRate, portMode_t mode, portOptions_t options) { - UNUSED(USARTx); - UNUSED(rxCallback); - UNUSED(rxCallbackData); - UNUSED(baudRate); - UNUSED(mode); - UNUSED(options); - return NULL; + uartPort_t *s = NULL; + if (USARTx == USART1) { s = serialUART1(baudRate, mode, options); } + else if (USARTx == USART2) { s = serialUART2(baudRate, mode, options); } + else if (USARTx == USART3) { s = serialUART3(baudRate, mode, options); } + else if (USARTx == USART4) { s = serialUART4(baudRate, mode, options); } + if (!s) { return NULL; } + s->port.rxCallback = rxCallback; + s->port.rxCallbackData = rxCallbackData; + return (serialPort_t *)s; } -// CMSIS DSP stubs (DSP library not compiled for RP2350 M1) -arm_status arm_rfft_fast_init_f32(arm_rfft_fast_instance_f32 *S, uint16_t fftLen) -{ - UNUSED(S); - UNUSED(fftLen); - return ARM_MATH_SUCCESS; -} - -void arm_cfft_radix8by4_f32(arm_cfft_instance_f32 *S, float32_t *p1) -{ - UNUSED(S); - UNUSED(p1); -} - -void arm_bitreversal_32(uint32_t *pSrc, const uint16_t bitRevLen, - const uint16_t *pBitRevTable) -{ - UNUSED(pSrc); - UNUSED(bitRevLen); - UNUSED(pBitRevTable); -} - -void stage_rfft_f32(arm_rfft_fast_instance_f32 *S, float32_t *p, float32_t *pOut) -{ - UNUSED(S); - UNUSED(p); - UNUSED(pOut); -} - -void arm_cmplx_mag_f32(float32_t *pSrc, float32_t *pDst, uint32_t numSamples) -{ - UNUSED(pSrc); - UNUSED(pDst); - UNUSED(numSamples); -} - -void arm_mult_f32(float32_t *pSrcA, float32_t *pSrcB, - float32_t *pDst, uint32_t blockSize) -{ - UNUSED(pSrcA); - UNUSED(pSrcB); - UNUSED(pDst); - UNUSED(blockSize); -} - -void arm_sub_f32(float32_t *pSrcA, float32_t *pSrcB, - float32_t *pDst, uint32_t blockSize) -{ - UNUSED(pSrcA); - UNUSED(pSrcB); - UNUSED(pDst); - UNUSED(blockSize); -} - -void arm_scale_f32(float32_t *pSrc, float32_t scale, - float32_t *pDst, uint32_t blockSize) -{ - UNUSED(pSrc); - UNUSED(scale); - UNUSED(pDst); - UNUSED(blockSize); -} Instead of stubbing CMSIS-DSP functions in target.c and using the ARM_MATH_CM4 flag as a workaround, consider a cleaner approach. Either update the CMSIS-DSP library or use #ifdef directives to conditionally compile the code that relies on these functions. Examples: src/main/target/RP2350_PICO/target.c [164-225] // CMSIS DSP stubs (DSP library not compiled for RP2350 M1) arm_status arm_rfft_fast_init_f32(arm_rfft_fast_instance_f32 *S, uint16_t fftLen) { UNUSED(S); UNUSED(fftLen); return ARM_MATH_SUCCESS; } void arm_cfft_radix8by4_f32(arm_cfft_instance_f32 *S, float32_t *p1) { ... (clipped 52 lines) cmake/cortex-m33.cmake [17-23] set(CORTEX_M33_DEFINITIONS __FPU_PRESENT=1 ARM_MATH_CM4 ARM_MATH_MATRIX_CHECK ARM_MATH_ROUNDING UNALIGNED_SUPPORT_DISABLE ) Solution Walkthrough: Before: // In cmake/cortex-m33.cmake set(CORTEX_M33_DEFINITIONS ... ARM_MATH_CM4 ... ) // In src/main/target/RP2350_PICO/target.c // CMSIS DSP stubs (DSP library not compiled for RP2350 M1) arm_status arm_rfft_fast_init_f32(...) { // Stub implementation return ARM_MATH_SUCCESS; } void arm_cmplx_mag_f32(...) { // Stub implementation } // ... more stubs After: // In cmake/cortex-m33.cmake set(CORTEX_M33_DEFINITIONS ... // ARM_MATH_CM4 is removed ... ) // In src/main/target/RP2350_PICO/target.c // The DSP stubs are removed. // In common code (e.g. sensor processing) #if defined(USE_CMSIS_DSP_FILTERS) // or similar new define // Existing code that calls CMSIS-DSP functions arm_rfft_fast_init_f32(...); arm_cmplx_mag_f32(...); #endif Suggestion importance[1-10]: 7 __ Why: The suggestion correctly identifies a temporary hack in the CMSIS-DSP integration for the new RP2350 target and proposes cleaner, more maintainable alternatives that improve the foundational quality of this new port.	Medium
Possible issue	Quote STREQUAL comparisons Quote arguments in STREQUAL comparisons to prevent potential errors if variables are empty. cmake/rp2350.cmake [79-81] -if(NOT arm-none-eabi STREQUAL TOOLCHAIN) +if(NOT "arm-none-eabi" STREQUAL "${TOOLCHAIN}") return() endif() ... -if (NOT generator_cmd STREQUAL "") +if (NOT "${generator_cmd}" STREQUAL "") [To ensure code accuracy, apply this suggestion manually] Suggestion importance[1-10]: 5 __ Why: The suggestion correctly identifies a potential bug in the CMake script where an empty TOOLCHAIN variable would cause a syntax error, and provides a robust fix by quoting the arguments.	Low
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