From 59aa1e7331690963289af22745bd31f3785d0c5b Mon Sep 17 00:00:00 2001
From: Peter Harper <peter.harper@raspberrypi.com>
Date: Fri, 12 Dec 2025 12:58:51 +0000
Subject: [PATCH] Flash functions in PICO_NO_FLASH binaries

We assume that PICO_NO_FLASH binaries means the device does not have
a flash chip. But it's possible that you want a ram binary AND want
to mess about with flash, e.g. for flash nuke or something that uses
the unique flash id.

Add PICO_INCLUDE_FLASH_UTILS which forces some flash functions to be
included.
---
 src/rp2_common/hardware_flash/flash.c                  | 4 ++--
 src/rp2_common/hardware_flash/include/hardware/flash.h | 5 +++++
 src/rp2_common/pico_unique_id/unique_id.c              | 2 +-
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/rp2_common/hardware_flash/flash.c b/src/rp2_common/hardware_flash/flash.c
index fbca8de2c..1008488e2 100644
--- a/src/rp2_common/hardware_flash/flash.c
+++ b/src/rp2_common/hardware_flash/flash.c
@@ -248,7 +248,7 @@ void __no_inline_not_in_flash_func(flash_range_program)(uint32_t flash_offs, con
 //-----------------------------------------------------------------------------
 // Lower-level flash access functions
 
-#if !PICO_NO_FLASH
+#if !PICO_NO_FLASH || PICO_INCLUDE_FLASH_UTILS
 // Bitbanging the chip select using IO overrides, in case RAM-resident IRQs
 // are still running, and the FIFO bottoms out. (the bootrom does the same)
 static void __no_inline_not_in_flash_func(flash_cs_force)(bool high) {
@@ -334,7 +334,7 @@ void __no_inline_not_in_flash_func(flash_do_cmd)(const uint8_t *txbuf, uint8_t *
 static_assert(FLASH_UNIQUE_ID_SIZE_BYTES == FLASH_RUID_DATA_BYTES, "");
 
 void flash_get_unique_id(uint8_t *id_out) {
-#if PICO_NO_FLASH
+#if PICO_NO_FLASH && !PICO_INCLUDE_FLASH_UTILS
     __unused uint8_t *ignore = id_out;
     panic_unsupported();
 #else
diff --git a/src/rp2_common/hardware_flash/include/hardware/flash.h b/src/rp2_common/hardware_flash/include/hardware/flash.h
index 2bb5d5ae3..8e05a65ea 100644
--- a/src/rp2_common/hardware_flash/include/hardware/flash.h
+++ b/src/rp2_common/hardware_flash/include/hardware/flash.h
@@ -52,6 +52,11 @@
 
 // PICO_CONFIG: PICO_FLASH_SIZE_BYTES, size of primary flash in bytes, type=int, default=Usually provided via board header, group=hardware_flash
 
+// PICO_CONFIG: PICO_INCLUDE_FLASH_UTILS, Force inclusion of flash functions in PICO_NO_FLASH binaries. Has no effect in flash binaries, type=bool, default=0, group=hardware_flash
+#ifndef PICO_INCLUDE_FLASH_UTILS
+#define PICO_INCLUDE_FLASH_UTILS 0
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/src/rp2_common/pico_unique_id/unique_id.c b/src/rp2_common/pico_unique_id/unique_id.c
index 28204eda0..abae77a30 100644
--- a/src/rp2_common/pico_unique_id/unique_id.c
+++ b/src/rp2_common/pico_unique_id/unique_id.c
@@ -20,7 +20,7 @@ static pico_unique_board_id_t retrieved_id;
 
 static void __attribute__((PICO_UNIQUE_BOARD_ID_INIT_ATTRIBUTES)) _retrieve_unique_id_on_boot(void) {
 #if PICO_RP2040
-    #if PICO_NO_FLASH
+    #if PICO_NO_FLASH && !PICO_INCLUDE_FLASH_UTILS
         // The hardware_flash call will panic() if called directly on a NO_FLASH
         // build. Since this constructor is pre-main it would be annoying to
         // debug, so just produce something well-defined and obviously wrong.