Add pico_low_power library

src/cmake/rp2_common.cmake

@@ -49,6 +49,7 @@ pico_add_subdirectory(rp2_common/hardware_pio)
 pico_add_subdirectory(rp2_common/hardware_pll)
 pico_add_subdirectory(rp2_common/hardware_pwm)
 pico_add_subdirectory(rp2_common/hardware_resets)
+pico_add_subdirectory(rp2_common/hardware_rosc)
 if (PICO_RP2040 OR PICO_COMBINED_DOCS)
     pico_add_subdirectory(rp2_common/hardware_rtc)
 endif()
@@ -103,6 +104,7 @@ if (NOT PICO_BARE_METAL)
     pico_add_subdirectory(rp2_common/pico_int64_ops)
     pico_add_subdirectory(rp2_common/pico_flash)
     pico_add_subdirectory(rp2_common/pico_float)
+    pico_add_subdirectory(rp2_common/pico_low_power)
     pico_add_subdirectory(rp2_common/pico_mem_ops)
     pico_add_subdirectory(rp2_common/pico_malloc)
     pico_add_subdirectory(rp2_common/pico_printf)

src/common/pico_base_headers/BUILD.bazel

@@ -118,6 +118,7 @@ cc_library(
         "//src/rp2_common/hardware_ticks:__pkg__",
         "//src/rp2_common/hardware_timer:__pkg__",
         "//src/rp2_common/hardware_watchdog:__pkg__",
+        "//src/rp2_common/hardware_rosc:__pkg__",
         "//src/rp2_common/hardware_xosc:__pkg__",
         "//src/rp2_common/pico_crt0:__pkg__",
         "//src/rp2_common/pico_platform_common:__pkg__",

src/common/pico_util/BUILD.bazel

@@ -6,11 +6,13 @@ package(default_visibility = ["//visibility:public"])
 cc_library(
     name = "pico_util",
     srcs = [
+        "fixed_bitset.c",
         "datetime.c",
         "pheap.c",
         "queue.c",
     ],
     hdrs = [
+        "include/pico/util/fixed_bitset.h",
         "include/pico/util/datetime.h",
         "include/pico/util/pheap.h",
         "include/pico/util/queue.h",

src/common/pico_util/CMakeLists.txt

@@ -8,6 +8,7 @@ if (NOT TARGET pico_util)
     pico_add_impl_library(pico_util)
     target_sources(pico_util INTERFACE
             ${CMAKE_CURRENT_LIST_DIR}/datetime.c
+            ${CMAKE_CURRENT_LIST_DIR}/fixed_bitset.c
             ${CMAKE_CURRENT_LIST_DIR}/pheap.c
             ${CMAKE_CURRENT_LIST_DIR}/queue.c
     )

src/common/pico_util/fixed_bitset.c

@@ -0,0 +1,26 @@
+/*
+* Copyright (c) 2026 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include "include/pico/util/fixed_bitset.h"
+
+fixed_bitset_t *fixed_bitset_flip_all(fixed_bitset_t *bitset) {
+    check_fixed_bitset(bitset);
+    for (uint i=0;i<bitset->word_size;i++) {
+        bitset->words[i] = ~bitset->words[i];
+    }
+    return bitset;
+}
+
+bool fixed_bitset_is_empty(fixed_bitset_t *bitset) {
+    check_fixed_bitset(bitset);
+    int i=0;
+    for (i=0;i<bitset->word_size-1;i++) {
+        if (bitset->words[i]) return false;
+    }
+    // we don't guarantee that bits above the size aren't set, so mask them off
+    return !(i && (bitset->words[i] << (32u -(bitset->size & 31u))));
+}
+

src/common/pico_util/include/pico/util/fixed_bitset.h

@@ -0,0 +1,283 @@
+/*
+ * Copyright (c) 2026 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef _PICO_UTIL_FIXED_BITSET_H
+#define _PICO_UTIL_FIXED_BITSET_H
+
+#include "pico.h"
+
+/** \file fixed_bitset.h
+ * \defgroup fixed_bitset fixed_bitset
+ * \brief Simple fixed-size bitset implementation
+ *
+ * \ingroup pico_util
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+    uint16_t size;           \
+    uint16_t word_size;     \
+    uint32_t words[];
+} fixed_bitset_t;
+
+/*! \brief Macro used to define a fixed-size bitset of a given size
+ * \ingroup fixed_bitset
+ * This macro is used to declare the type of a fixed-size bitset. It is used as follows:
+ * ```
+ * typedef fixed_bitset_type_t(17) my_bitset_t;
+ * ```
+ * will define a new bitset type called `my_bitset_t` that can hold 17 boolean values.
+ * 
+ * The type can be used as `my_bitset_t bitset;` to declare a new bitset.
+ * 
+ * \param N the number of boolean values in the bitset
+ */
+#define fixed_bitset_type(N) union { \
+    fixed_bitset_t bitset;      \
+    struct {                    \
+        uint16_t size;          \
+        uint16_t word_size;     \
+        uint32_t words[((N) + 31) / 32]; \
+    } sized_bitset;             \
+}
+#define fixed_bitset_sizeof_for(N) ((((N) + 63u) / 32u) * 4u)
+
+/*! \brief Macro used to create a bitset with all bits set to a value
+ * \ingroup fixed_bitset
+ * \param type the type of the bitset
+ * \param N the number of bits in the bitset
+ * \param fill the value to set the bits to (0 or 1)
+ * \return the bitset
+ */
+#define fixed_bitset_with_fill(type, N, fill) ({ type bitset; fixed_bitset_init(&bitset, type, N, fill); bitset; })
+
+// Quick test that the bitset macros give the correct size
+extern fixed_bitset_type(32) __not_real_bitset32;
+extern fixed_bitset_type(33) __not_real_bitset33;
+static_assert(sizeof(__not_real_bitset32) == fixed_bitset_sizeof_for(1),"");
+static_assert(sizeof(__not_real_bitset33) == fixed_bitset_sizeof_for(37), "");
+static_assert(sizeof(__not_real_bitset33) != fixed_bitset_sizeof_for(1), "");
+
+/*! \brief Initialize a bitset
+ * \ingroup fixed_bitset
+ * \param ptr the bitset to initialize
+ * \param type the type of the bitset
+ * \param N the number of bits in the bitset
+ * \param fill the value to fill the bitset with (0 or 1)
+ */
+#define fixed_bitset_init(ptr, type, N, fill) ({ \
+    assert(sizeof(type) == fixed_bitset_sizeof_for(N)); \
+    __unused type *type_check = ptr; \
+    (ptr)->bitset.size = N; \
+    (ptr)->bitset.word_size = ((N) + 31u) / 32u; \
+    __builtin_memset(&(ptr)->bitset.words, (fill) ? 0xff : 0, (ptr)->bitset.word_size * sizeof(uint32_t)); \
+})
+
+/*! \brief Get the size of the bitset
+ * \ingroup fixed_bitset
+ * \param bitset the bitset to get the size of
+ * \return the size of the bitset
+ */
+static inline uint fixed_bitset_size(const fixed_bitset_t *bitset) {
+    return bitset->size;
+}
+
+/*! \brief Get the size of the bitset in words
+ * \ingroup fixed_bitset
+ * \param bitset the bitset to get the size of
+ * \return the size of the bitset in words
+ */
+static inline uint fixed_bitset_word_size(const fixed_bitset_t *bitset) {
+    return bitset->word_size;
+}
+
+/*! \brief Check that the bitset is valid
+ * \ingroup fixed_bitset
+ * This function will assert if the bitset is not valid.
+ * \param bitset the bitset to check
+ */
+static inline void check_fixed_bitset(__unused const fixed_bitset_t *bitset) {
+    assert(bitset->word_size == (bitset->size + 31) / 32);
+}
+
+/*! \brief Write a word in the bitset
+ * \ingroup fixed_bitset
+ * \param bitset the bitset to write to
+ * \param word_num the word number to write to
+ * \param value the value to write to the word
+ * \return the bitset
+ */
+static inline fixed_bitset_t *fixed_bitset_write_word(fixed_bitset_t *bitset, uint word_num, uint32_t value) {
+    check_fixed_bitset(bitset);
+    if (word_num < fixed_bitset_word_size(bitset)) {
+        bitset->words[word_num] = value;
+    }
+    return bitset;
+}
+
+/*! \brief Read a word in the bitset
+ * \ingroup fixed_bitset
+ * \param bitset the bitset
+ * \param word_num the word number to read from
+ * \return the value of the word
+ */
+static inline uint32_t fixed_bitset_read_word(const fixed_bitset_t *bitset, uint word_num) {
+    check_fixed_bitset(bitset);
+    if (word_num < fixed_bitset_word_size(bitset)) {
+        return bitset->words[word_num];
+    }
+    return 0;
+}
+
+/*! \brief Clear all bits in the bitset
+ * \ingroup fixed_bitset
+ * \param bitset the bitset
+ * \return the bitset
+ */
+static inline fixed_bitset_t *fixed_bitset_clear_all(fixed_bitset_t *bitset) {
+    check_fixed_bitset(bitset);
+    __builtin_memset(bitset->words, 0, bitset->word_size * sizeof(uint32_t));
+    return bitset;
+}
+
+/*! \brief Set all bits in the bitset
+ * \ingroup fixed_bitset
+ * \param bitset the bitset
+ * \return the bitset
+ */
+static inline fixed_bitset_t *fixed_bitset_set_all(fixed_bitset_t *bitset) {
+    check_fixed_bitset(bitset);
+    __builtin_memset(bitset->words, 0xff, bitset->word_size * sizeof(uint32_t));
+    return bitset;
+}
+
+/*! \brief Flip all bits in the bitset
+ * \ingroup fixed_bitset
+ * \param bitset the bitset
+ * \return the bitset
+ */
+fixed_bitset_t *fixed_bitset_flip_all(fixed_bitset_t *bitset);
+
+/*! \brief Determine if bitset is empty
+ * \ingroup fixed_bitset
+ * \param bitset the bitset
+ * \return true if not bits are set
+ */
+bool fixed_bitset_is_empty(fixed_bitset_t *bitset);
+
+/*! \brief Set a single bit in the bitset
+ * \ingroup fixed_bitset
+ * \param bitset the bitset
+ * \param bit_index the bit to set
+ * \return the bitset
+ */
+static inline fixed_bitset_t *fixed_bitset_set(fixed_bitset_t *bitset, uint bit_index) {
+    check_fixed_bitset(bitset);
+    if (bit_index < bitset->size) {
+        bitset->words[bit_index / 32u] |= 1u << (bit_index % 32u);
+    }
+    return bitset;
+}
+
+/*! \brief Clear a single bit in the bitset
+ * \ingroup fixed_bitset
+ * \param bitset the bitset
+ * \param bit_index the bit to clear
+ * \return the bitset
+ */
+static inline fixed_bitset_t *fixed_bitset_clear(fixed_bitset_t *bitset, uint bit_index) {
+    check_fixed_bitset(bitset);
+    if (bit_index < bitset->size) {
+        bitset->words[bit_index / 32u] &= ~(1u << (bit_index % 32u));
+    }
+    return bitset;
+}
+
+/*! \brief Flip a single bit in the bitset
+ * \ingroup fixed_bitset
+ * \param bitset the bitset
+ * \param bit_index the bit to flip
+ * \return the bitset
+ */
+static inline fixed_bitset_t *fixed_bitset_flip(fixed_bitset_t *bitset, uint bit_index) {
+    check_fixed_bitset(bitset);
+    if (bit_index < bitset->size) {
+        bitset->words[bit_index / 32u] ^= 1u << (bit_index % 32u);
+    }
+    return bitset;
+}
+
+
+/*! \brief Get the value of a single bit in the bitset
+ * \ingroup fixed_bitset
+ * \param bitset the bitset
+ * \param bit_index the bit to get the value of
+ * \return the value of the bit
+ */
+static inline bool fixed_bitset_get(const fixed_bitset_t *bitset, uint bit_index) {
+    check_fixed_bitset(bitset);
+    assert(bit_index < bitset->size);
+//    if (bit < bitset->size) {
+        return bitset->words[bit_index / 32u] & (1u << (bit_index % 32u));
+//    }
+    return false;
+}
+
+/*! \brief Check if two bitsets are equal
+ * \ingroup fixed_bitset
+ * \param bitset1 the first bitset to check
+ * \param bitset2 the second bitset to check
+ * \return true if the bitsets are equal, false otherwise
+ */
+static inline bool fixed_bitset_equal(const fixed_bitset_t *bitset1, const fixed_bitset_t *bitset2) {
+    check_fixed_bitset(bitset1);
+    check_fixed_bitset(bitset2);
+    assert(bitset1->size == bitset2->size);
+    return __builtin_memcmp(bitset1->words, bitset2->words, bitset1->word_size * sizeof(uint32_t)) == 0;
+}
+
+#if 0 // not currently used
+typedef uint32_t tiny_ordinal_list_t; // ordinals must be 0->255
+typedef uint64_t small_ordinal_list_t; // ordinals must be 0->255
+#define ordinal_list_empty() 0
+#define ordinal_list_of1(v) (1u | ((v) << 8))
+#define ordinal_list_of2(v1, v2) (2u | ((v1) << 8) | ((v2) << 16))
+#define ordinal_list_of3(v1, v2, v3) (3u | ((v1) << 8) | ((v2) << 16) | (((v3) << 24)))
+#define ordinal_list_of4(v1, v2, v3, v4) (4u | ((v1) << 8) | ((v2) << 16) | (((v3) << 24)) | (((uint64_t)(v4)) << 32))
+#define ordinal_list_of5(v1, v2, v3, v4, v5) (5u | ((v1) << 8) | ((v2) << 16) | (((v3) << 24)) | (((uint64_t)((v4) | ((v5)<<8u))) << 32))
+
+#define small_ordinal_list_foreach(bitarray, x) ({ \
+    for(uint _i=1;_i<=((bitarray)&0xffu);_i++) { \
+        uint bit = (uint8_t)((bitarray) >> (8 * _i)); \
+        x; \
+    } \
+})
+
+static inline fixed_bitset_t *fixed_bitset_set_bits(fixed_bitset_t *bitset, small_ordinal_list_t list) {
+    small_ordinal_list_foreach(list, fixed_bitset_set(bitset, bit));
+    return bitset;
+}
+
+static inline fixed_bitset_t *fixed_bitset_clear_bits(fixed_bitset_t *bitset, small_ordinal_list_t list) {
+    small_ordinal_list_foreach(list, fixed_bitset_clear(bitset, bit));
+    return bitset;
+}
+
+
+#define fixed_bitset_init_with_bits(ptr, type, N, list) ({ \
+    /* not this performs checks */ \
+    fixed_bitset_init(ptr, type, N, 0); \
+    fixed_bitset_set_bits(&(ptr)->bitset, list); \
+})
+
+#endif
+#ifdef __cplusplus
+}
+#endif
+#endif

src/rp2040/pico_platform/memmap_blocked_ram.ld

@@ -33,7 +33,8 @@ INCLUDE "memmap_default.incl"
  *         │   ├── section_ram_vector_table.incl         rp2_common/pico_standard_link
  *         │   ├── section_uninitialized_data.incl       rp2_common/pico_standard_link
  *         │   ├── section_default_data.incl             rp2_common/pico_standard_link
- *         │   └── section_bss.incl                      rp2_common/pico_standard_link
+ *         │   ├── section_bss.incl                      rp2_common/pico_standard_link
+ *         │   └── section_persistent_data.incl          rp2_common/pico_standard_link
  *         ├── section_generated_post_data.incl          rp2_common/pico_standard_link
  *         ├── section_extra_post_data.incl              rp2_common/pico_standard_link
  *         ├── section_heap.incl                         rp2_common/pico_standard_link

src/rp2040/pico_platform/memmap_copy_to_ram.ld

@@ -29,7 +29,8 @@ INCLUDE "memmap_copy_to_ram.incl"
  *         ├── section_extra_post_text.incl              rp2_common/pico_standard_link
  *         ├── sections_copy_to_ram_data.incl            rp2_common/pico_standard_link
  *         │   ├── section_copy_to_ram_data.incl         rp2_common/pico_standard_link
- *         │   └── section_bss.incl                      rp2_common/pico_standard_link
+ *         │   ├── section_bss.incl                      rp2_common/pico_standard_link
+ *         │   └── section_persistent_data.incl          rp2_common/pico_standard_link
  *         ├── section_generated_post_data.incl          rp2_common/pico_standard_link
  *         ├── section_extra_post_data.incl              rp2_common/pico_standard_link
  *         ├── section_heap.incl                         rp2_common/pico_standard_link

src/rp2040/pico_platform/memmap_default.ld

@@ -30,7 +30,8 @@ INCLUDE "memmap_default.incl"
  *         │   ├── section_ram_vector_table.incl         rp2_common/pico_standard_link
  *         │   ├── section_uninitialized_data.incl       rp2_common/pico_standard_link
  *         │   ├── section_default_data.incl             rp2_common/pico_standard_link
- *         │   └── section_bss.incl                      rp2_common/pico_standard_link
+ *         │   ├── section_bss.incl                      rp2_common/pico_standard_link
+ *         │   └── section_persistent_data.incl          rp2_common/pico_standard_link
  *         ├── section_generated_post_data.incl          rp2_common/pico_standard_link
  *         ├── section_extra_post_data.incl              rp2_common/pico_standard_link
  *         ├── section_heap.incl                         rp2_common/pico_standard_link

src/rp2040/pico_platform/memmap_no_flash.ld

@@ -24,7 +24,8 @@ INCLUDE "memmap_no_flash.incl"
  *         ├── sections_no_flash_data.incl               rp2_common/pico_standard_link
  *         │   ├── section_no_flash_data.incl            rp2_common/pico_standard_link
  *         │   ├── section_uninitialized_data.incl       rp2_common/pico_standard_link
- *         │   └── section_bss.incl                      rp2_common/pico_standard_link
+ *         │   ├── section_bss.incl                      rp2_common/pico_standard_link
+ *         │   └── section_persistent_data.incl          rp2_common/pico_standard_link
  *         ├── section_generated_post_data.incl          rp2_common/pico_standard_link
  *         ├── section_extra_post_data.incl              rp2_common/pico_standard_link
  *         ├── section_heap.incl                         rp2_common/pico_standard_link