From c93c3e46d69c7912b81c183a8abc8554f6330b05 Mon Sep 17 00:00:00 2001
From: Koen Zandberg <koen@bergzand.net>
Date: Tue, 10 Nov 2020 15:06:24 +0100
Subject: [PATCH 1/2] flashpage: Support non uniform flashpage sizes

---
 drivers/include/periph/flashpage.h | 45 ++++++++++++++++++++++++++----
 drivers/periph_common/flashpage.c  |  4 +--
 2 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/drivers/include/periph/flashpage.h b/drivers/include/periph/flashpage.h
index ae7ab3cc9c..2153b84f95 100644
--- a/drivers/include/periph/flashpage.h
+++ b/drivers/include/periph/flashpage.h
@@ -84,6 +84,27 @@ extern "C" {
 #ifdef DOXYGEN
 #define FLASHPAGE_WRITE_BLOCK_ALIGNMENT
 #endif
+
+/**
+ * @def     PERIPH_FLASHPAGE_CUSTOM_PAGESIZES
+ *
+ * @brief   Defined to signal that the peripheral has non-uniform flash page
+ *          sizes. These devices do not define FLASHPAGE_SIZE and do not
+ *          implement the pagewise api.
+ */
+#ifdef DOXYGEN
+#define PERIPH_FLASHPAGE_CUSTOM_PAGESIZES
+#endif
+
+/**
+ * @brief   Return values used in this interface
+ */
+enum {
+    FLASHPAGE_OK      =  0,     /**< everything succeeded */
+    FLASHPAGE_NOMATCH = -1      /**< page differs from target data */
+};
+
+#if !defined(PERIPH_FLASHPAGE_CUSTOM_PAGESIZES) || defined(DOXYGEN)
 /**
  * @def FLASHPAGE_SIZE
  *
@@ -97,12 +118,17 @@ extern "C" {
 #endif
 
 /**
- * @brief   Return values used in this interface
+ * @brief   Get the page size of the given page number
+ *
+ * @param[in] page      page number to get the size for
+ *
+ * @return              Page size of the given page
  */
-enum {
-    FLASHPAGE_OK      =  0,     /**< everything succeeded */
-    FLASHPAGE_NOMATCH = -1      /**< page differs from target data */
-};
+static inline size_t flashpage_size(unsigned page)
+{
+    (void)page;
+    return FLASHPAGE_SIZE;
+}
 
 /**
  * @brief   Translate the given page number into the page's starting address
@@ -135,6 +161,15 @@ static inline unsigned flashpage_page(void *addr)
     return (((intptr_t)addr - CPU_FLASH_BASE) / FLASHPAGE_SIZE);
 }
 
+#else
+
+/* Bare prototypes for the above functions. See above for the documentation */
+size_t flashpage_size(unsigned page);
+void *flashpage_addr(unsigned page);
+unsigned flashpage_page(void *addr);
+
+#endif
+
 /**
  * @brief   Erase the given page
  *
diff --git a/drivers/periph_common/flashpage.c b/drivers/periph_common/flashpage.c
index 3ef346eaec..8d0f4a4640 100644
--- a/drivers/periph_common/flashpage.c
+++ b/drivers/periph_common/flashpage.c
@@ -37,7 +37,7 @@ void flashpage_read(unsigned page, void *data)
     assert(page < (FLASH->SFR & FLASH_SFR_SFSA));
 #endif
 
-    memcpy(data, flashpage_addr(page), FLASHPAGE_SIZE);
+    memcpy(data, flashpage_addr(page), flashpage_size(page));
 }
 
 int flashpage_verify(unsigned page, const void *data)
@@ -48,7 +48,7 @@ int flashpage_verify(unsigned page, const void *data)
     assert(page < (int)(FLASH->SFR & FLASH_SFR_SFSA));
 #endif
 
-    if (memcmp(flashpage_addr(page), data, FLASHPAGE_SIZE) == 0) {
+    if (memcmp(flashpage_addr(page), data, flashpage_size(page)) == 0) {
         return FLASHPAGE_OK;
     }
     else {

From 5b0eaf7cd8bc4419b27f993b68d03ad440ef7a22 Mon Sep 17 00:00:00 2001
From: Koen Zandberg <koen@bergzand.net>
Date: Mon, 1 Feb 2021 12:55:26 +0100
Subject: [PATCH 2/2] riotboot/flashwrite: Remove last dependencies on
 flashpage size

---
 sys/riotboot/flashwrite.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/sys/riotboot/flashwrite.c b/sys/riotboot/flashwrite.c
index a9d102dbda..e5ef3134ae 100644
--- a/sys/riotboot/flashwrite.c
+++ b/sys/riotboot/flashwrite.c
@@ -49,9 +49,15 @@ size_t riotboot_flashwrite_slotsize(
 int riotboot_flashwrite_init_raw(riotboot_flashwrite_t *state, int target_slot,
                              size_t offset)
 {
+#ifdef FLASHPAGE_SIZE
     assert(offset <= FLASHPAGE_SIZE);
     /* the flashpage size must be a multiple of the riotboot flashpage buffer */
     static_assert(!(FLASHPAGE_SIZE % RIOTBOOT_FLASHPAGE_BUFFER_SIZE));
+#else
+    /* The flashpage buffer must be a multiple of the write block size */
+    static_assert(!(RIOTBOOT_FLASHPAGE_BUFFER_SIZE % FLASHPAGE_WRITE_BLOCK_SIZE));
+#endif
+
 
     LOG_INFO(LOG_PREFIX "initializing update to target slot %i\n",
              target_slot);
@@ -103,15 +109,20 @@ int riotboot_flashwrite_putbytes(riotboot_flashwrite_t *state,
     LOG_DEBUG(LOG_PREFIX "processing bytes %u-%u\n", state->offset, state->offset + len - 1);
 
     while (len) {
-        size_t flashpage_pos = state->offset % FLASHPAGE_SIZE;
+        /* Position within the page, calculated from state->offset by
+         * subtracting the start offset of the current page */
+        size_t flashpage_pos = state->offset -
+            (flashpage_addr(state->flashpage) - (void*)riotboot_slot_get_hdr(state->target_slot));
         size_t flashwrite_buffer_pos = state->offset % RIOTBOOT_FLASHPAGE_BUFFER_SIZE;
         size_t flashpage_avail = RIOTBOOT_FLASHPAGE_BUFFER_SIZE - flashwrite_buffer_pos;
 
         size_t to_copy = min(flashpage_avail, len);
 
-        if (CONFIG_RIOTBOOT_FLASHWRITE_RAW && flashpage_pos == 0) {
+        if (CONFIG_RIOTBOOT_FLASHWRITE_RAW &&
+                flashpage_pos == flashpage_size(state->flashpage)) {
             /* Erase the next page */
             state->flashpage++;
+            flashpage_pos = 0;
             flashpage_erase(state->flashpage);
         }
         if (CONFIG_RIOTBOOT_FLASHWRITE_RAW &&