RP2350: boot_stage2 never run? resulting in incorrect flash config

[asumagic]

I recently noticed that PICO_FLASH_SPI_CLKDIV was not having any effect on my project ported to RP2350, whereas it worked fine with RP2040 before.

This reproduced when using the stock Pico 2 and Pimoroni Pico Plus 2 board files, which use the same boot2_w25q080.S boot_stage2. It does get assembled.

The QMI timing values I am seeing on a MCVE (provided below) don't match my expectations reading the boot script.

qmi[0].timing = 60007203
qmi[0].rfmt   = 492a8
qmi[0].rcmd   = 00eb

When ripping out all the code from boot2_w25q080.S, behavior is unchanged! (Adding garbage to it, it fails to assemble, so it is still getting selected somewhere.)

The lower byte of timing should be 2 (the default CLKDIV), the rcmd is missing the upper byte that should have gotten configured, etc. -- so I am assuming it is inheriting whatever the bootrom had configured.

(EDIT: Writing to those regs works fine; I've been doing it.)

I observed this issue both selecting the 2.0.0 tag and the latest develop tip.

Repro:

#include <stdio.h>
#include <hardware/structs/qmi.h>
#include <hardware/structs/xip.h>
#include <pico/stdlib.h>

int main()
{
    stdio_init_all();
    while (true) {
        printf("qmi[0].timing = %04x\n", qmi_hw->m[0].timing);
        printf("qmi[0].rfmt   = %04x\n", qmi_hw->m[0].rfmt);
        printf("qmi[0].rcmd   = %04x\n", qmi_hw->m[0].rcmd);
        sleep_ms(1000);
    }

}

cmake_minimum_required(VERSION 3.13)

include(pico_sdk_import.cmake)

project(pico-sdk-boot2-rp2350-repro LANGUAGES C CXX ASM)
pico_sdk_init()

add_executable(repro main.c)
target_link_libraries(repro pico_stdlib pico_stdio)
pico_enable_stdio_usb(repro 1)
pico_enable_stdio_uart(repro 0)
pico_add_extra_outputs(repro)

#!/bin/bash
set -ex
mkdir build -p
cd build
cmake .. -DPICO_BOARD=pico2 -DPICO_PLATFORM=rp2350-arm-s -DPICO_COMPILER=pico_arm_cortex_m33_gcc -DPICO_SDK_PATH="<whatever_sdk_path_here>"  -GNinja
cmake --build .

[kilograham]

Per release notes:

• A boot_stage2 is not needed on RP2350, but one can be included via the define PICO_EMBED_XIP_SETUP=1.

Could perhaps be better documented (this is a compile definition).. also perhaps surprising that it builds without it but that is orthogonal

[asumagic]

For clarification, by "ripping out all the code" from the stage2 I mostly meant the instructions under _stage2_boot.

But thank you, PICO_EMBED_XIP_SETUP=1 does indeed solve the problem. However, shouldn't that be the default for any non-default flash configuration?