boot: RFC: WIP: Preliminary work on flash_area open-once

The code has been modified to have single place where flash_area
area opened, at the beginning of execution.
Currently only Zephyr compiles properly and works.
close is missing.

Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>

boot/bootutil/include/bootutil/bootutil.h

@@ -77,6 +77,26 @@ struct image_trailer {
     uint8_t magic[BOOT_MAGIC_SZ];
 };
 
+#if defined(MCUBOOT_SINGLE_APPLICATION_SLOT)
+#define FLASH_AREA_IMAGES 1
+#elif MCUBOOT_IMAGE_NUMBER == 1
+#define FLASH_AREA_IMAGES 2
+#elif MCUBOOT_IMAGE_NUMBER == 2
+#define FLASH_AREA_IMAGES 4
+#endif
+
+#if !defined(MCUBOOT_SWAP_USING_SCRATCH)
+#define FLASH_AREA_OBJECTS FLASH_AREA_IMAGES
+#else
+#define FLASH_AREA_OBJECTS (FLASH_AREA_IMAGES + 1)
+#define SCRATCH_FA flash_area_objects[FLASH_AREA_OBJECTS - 1]
+#endif
+
+extern const struct flash_area *flash_area_objects[FLASH_AREA_OBJECTS];
+
+#define PRIMARY_IMAGE_FA(x) flash_area_objects[0]
+#define SECONDARY_IMAGE_FA(x) flash_area_objects[1]
+
 /* you must have pre-allocated all the entries within this structure */
 fih_int boot_go(struct boot_rsp *rsp);
 fih_int boot_go_for_image_id(struct boot_rsp *rsp, uint32_t image_id);

boot/bootutil/src/bootutil_priv.h

@@ -56,9 +56,10 @@ struct flash_area;
 
 #if (defined(MCUBOOT_OVERWRITE_ONLY) + \
      defined(MCUBOOT_SWAP_USING_MOVE) + \
+     defined(MCUBOOT_SWAP_USING_SCRATCH) + \
      defined(MCUBOOT_DIRECT_XIP) + \
      defined(MCUBOOT_RAM_LOAD)) > 1
-#error "Please enable only one of MCUBOOT_OVERWRITE_ONLY, MCUBOOT_SWAP_USING_MOVE, MCUBOOT_DIRECT_XIP or MCUBOOT_RAM_LOAD"
+#error "Please enable only one of MCUBOOT_OVERWRITE_ONLY, MCUBOOT_SWAP_USING_MOVE, MCUBOOT_SWAP_USING_SCRATCH, MCUBOOT_DIRECT_XIP or MCUBOOT_RAM_LOAD"
 #endif
 
 #if !defined(MCUBOOT_OVERWRITE_ONLY) && \

boot/bootutil/src/bootutil_public.c

@@ -432,15 +432,15 @@ boot_swap_type_multi(int image_index)
                         BOOT_HOOK_REGULAR, image_index, &primary_slot);
     if (rc == BOOT_HOOK_REGULAR)
     {
-        rc = boot_read_swap_state_by_id(FLASH_AREA_IMAGE_PRIMARY(image_index),
-                                        &primary_slot);
+        rc = boot_read_swap_state(PRIMARY_IMAGE_FA(image_index),
+                                  &primary_slot);
     }
     if (rc) {
         return BOOT_SWAP_TYPE_PANIC;
     }
 
-    rc = boot_read_swap_state_by_id(FLASH_AREA_IMAGE_SECONDARY(image_index),
-                                    &secondary_slot);
+    rc = boot_read_swap_state(SECONDARY_IMAGE_FA(image_index),
+                              &secondary_slot);
     if (rc == BOOT_EFLASH) {
         BOOT_LOG_INF("Secondary image of image pair (%d.) "
                      "is unreachable. Treat it as empty", image_index);

boot/bootutil/src/encrypted.c

@@ -698,7 +698,7 @@ boot_enc_load(struct enc_key_data *enc_state, int image_index,
     uint8_t slot;
     int rc;
 
-    rc = flash_area_id_to_multi_image_slot(image_index, flash_area_get_id(fap));
+    rc = flash_area_multi_image_slot(image_index, fap);
     if (rc < 0) {
         return rc;
     }
@@ -745,7 +745,7 @@ boot_enc_valid(struct enc_key_data *enc_state, int image_index,
 {
     int rc;
 
-    rc = flash_area_id_to_multi_image_slot(image_index, flash_area_get_id(fap));
+    rc = flash_area_to_multi_image_slot(image_index, fap);
     if (rc < 0) {
         /* can't get proper slot number - skip encryption, */
         /* postpone the error for a upper layer */
@@ -777,7 +777,7 @@ boot_encrypt(struct enc_key_data *enc_state, int image_index,
     nonce[14] = (uint8_t)(off >> 8);
     nonce[15] = (uint8_t)off;
 
-    rc = flash_area_id_to_multi_image_slot(image_index, flash_area_get_id(fap));
+    rc = flash_area_to_multi_image_slot(image_index, fap);
     if (rc < 0) {
         assert(0);
         return;

boot/bootutil/src/loader.c

@@ -35,6 +35,7 @@
 #include <inttypes.h>
 #include <stdlib.h>
 #include <string.h>
+#include "mcuboot_config/mcuboot_config.h"
 #include "bootutil/bootutil.h"
 #include "bootutil/bootutil_public.h"
 #include "bootutil/image.h"
@@ -56,7 +57,6 @@
 #include <os/os_malloc.h>
 #endif
 
-#include "mcuboot_config/mcuboot_config.h"
 
 BOOT_LOG_MODULE_DECLARE(mcuboot);
 
@@ -240,12 +240,7 @@ boot_read_image_size(struct boot_loader_state *state, int slot, uint32_t *size)
     (void)state;
 #endif
 
-    area_id = flash_area_id_from_multi_image_slot(BOOT_CURR_IMG(state), slot);
-    rc = flash_area_open(area_id, &fap);
-    if (rc != 0) {
-        rc = BOOT_EFLASH;
-        goto done;
-    }
+    fap = flash_area_from_multi_image_slot(BOOT_CURR_IMG(state), slot);
 
     off = BOOT_TLV_OFF(boot_img_hdr(state, slot));
 
@@ -309,7 +304,7 @@ boot_write_sz(struct boot_loader_state *state)
 }
 
 static int
-boot_initialize_area(struct boot_loader_state *state, int flash_area)
+boot_initialize_area(struct boot_loader_state *state, const struct flash_area *fa)
 {
     uint32_t num_sectors = BOOT_MAX_IMG_SECTORS;
     boot_sector_t *out_sectors;
@@ -318,14 +313,14 @@ boot_initialize_area(struct boot_loader_state *state, int flash_area)
 
     num_sectors = BOOT_MAX_IMG_SECTORS;
 
-    if (flash_area == FLASH_AREA_IMAGE_PRIMARY(BOOT_CURR_IMG(state))) {
+    if (fa == PRIMARY_IMAGE_FA(BOOT_CURR_IMG(state))) {
         out_sectors = BOOT_IMG(state, BOOT_PRIMARY_SLOT).sectors;
         out_num_sectors = &BOOT_IMG(state, BOOT_PRIMARY_SLOT).num_sectors;
-    } else if (flash_area == FLASH_AREA_IMAGE_SECONDARY(BOOT_CURR_IMG(state))) {
+    } else if (fa == SECONDARY_IMAGE_FA(BOOT_CURR_IMG(state))) {
         out_sectors = BOOT_IMG(state, BOOT_SECONDARY_SLOT).sectors;
         out_num_sectors = &BOOT_IMG(state, BOOT_SECONDARY_SLOT).num_sectors;
 #if MCUBOOT_SWAP_USING_SCRATCH
-    } else if (flash_area == FLASH_AREA_IMAGE_SCRATCH) {
+    } else if (fa == SCRATCH_FA) {
         out_sectors = state->scratch.sectors;
         out_num_sectors = &state->scratch.num_sectors;
 #endif
@@ -334,8 +329,12 @@ boot_initialize_area(struct boot_loader_state *state, int flash_area)
     }
 
 #ifdef MCUBOOT_USE_FLASH_AREA_GET_SECTORS
-    rc = flash_area_get_sectors(flash_area, &num_sectors, out_sectors);
+    rc = flash_area_get_sectors_fa(fa, &num_sectors, out_sectors);
 #else
+    /* TODO: This is only used by mynewt; note that flash_area_to_sectors
+     * actually does flash_area_open/flash_area_close pair but this safe for now,
+     * as these function do no locking or reference counting. */
+    int flash_area = flash_area_get_id(fa);
     _Static_assert(sizeof(int) <= sizeof(uint32_t), "Fix needed");
     rc = flash_area_to_sectors(flash_area, (int *)&num_sectors, out_sectors);
 #endif /* defined(MCUBOOT_USE_FLASH_AREA_GET_SECTORS) */
@@ -360,12 +359,12 @@ boot_read_sectors(struct boot_loader_state *state)
 
     image_index = BOOT_CURR_IMG(state);
 
-    rc = boot_initialize_area(state, FLASH_AREA_IMAGE_PRIMARY(image_index));
+    rc = boot_initialize_area(state, PRIMARY_IMAGE_FA(image_index));
     if (rc != 0) {
         return BOOT_EFLASH;
     }
 
-    rc = boot_initialize_area(state, FLASH_AREA_IMAGE_SECONDARY(image_index));
+    rc = boot_initialize_area(state, SECONDARY_IMAGE_FA(image_index));
     if (rc != 0) {
         /* We need to differentiate from the primary image issue */
         return BOOT_EFLASH_SEC;
@@ -596,14 +595,9 @@ boot_check_header_erased(struct boot_loader_state *state, int slot)
     int area_id;
     int rc;
 
-    area_id = flash_area_id_from_multi_image_slot(BOOT_CURR_IMG(state), slot);
-    rc = flash_area_open(area_id, &fap);
-    if (rc != 0) {
-        return -1;
-    }
+    fap = flash_area_from_multi_image_slot(BOOT_CURR_IMG(state), slot);
 
     erased_val = flash_area_erased_val(fap);
-    flash_area_close(fap);
 
     hdr = boot_img_hdr(state, slot);
     if (!boot_data_is_set_to(erased_val, &hdr->ih_magic, sizeof(hdr->ih_magic))) {
@@ -712,11 +706,7 @@ boot_validate_slot(struct boot_loader_state *state, int slot,
     fih_int fih_rc = FIH_FAILURE;
     int rc;
 
-    area_id = flash_area_id_from_multi_image_slot(BOOT_CURR_IMG(state), slot);
-    rc = flash_area_open(area_id, &fap);
-    if (rc != 0) {
-        FIH_RET(fih_rc);
-    }
+    fap = flash_area_from_multi_image_slot(BOOT_CURR_IMG(state), slot);
 
     hdr = boot_img_hdr(state, slot);
     if (boot_check_header_erased(state, slot) == 0 ||
@@ -817,8 +807,6 @@ boot_validate_slot(struct boot_loader_state *state, int slot,
 #endif
 
 out:
-    flash_area_close(fap);
-
     FIH_RET(fih_rc);
 }
 
@@ -844,12 +832,7 @@ boot_update_security_counter(uint8_t image_index, int slot,
     uint32_t img_security_cnt;
     int rc;
 
-    rc = flash_area_open(flash_area_id_from_multi_image_slot(image_index, slot),
-                         &fap);
-    if (rc != 0) {
-        rc = BOOT_EFLASH;
-        goto done;
-    }
+    fap = flash_area_from_multi_image_slot(image_index, slot);
 
     rc = bootutil_get_img_security_cnt(hdr, fap, &img_security_cnt);
     if (rc != 0) {
@@ -862,7 +845,6 @@ boot_update_security_counter(uint8_t image_index, int slot,
     }
 
 done:
-    flash_area_close(fap);
     return rc;
 }
 #endif /* MCUBOOT_HW_ROLLBACK_PROT */
@@ -1410,12 +1392,7 @@ boot_verify_slot_dependencies(struct boot_loader_state *state, uint32_t slot)
     int area_id;
     int rc;
 
-    area_id = flash_area_id_from_multi_image_slot(BOOT_CURR_IMG(state), slot);
-    rc = flash_area_open(area_id, &fap);
-    if (rc != 0) {
-        rc = BOOT_EFLASH;
-        goto done;
-    }
+    fap = flash_area_from_multi_image_slot(BOOT_CURR_IMG(state), slot);
 
     rc = bootutil_tlv_iter_begin(&it, boot_img_hdr(state, slot), fap,
             IMAGE_TLV_DEPENDENCY, true);
@@ -1457,7 +1434,6 @@ boot_verify_slot_dependencies(struct boot_loader_state *state, uint32_t slot)
     }
 
 done:
-    flash_area_close(fap);
     return rc;
 }
 
@@ -1966,7 +1942,6 @@ context_boot_go(struct boot_loader_state *state, struct boot_rsp *rsp)
     struct boot_status bs;
     int rc = -1;
     fih_int fih_rc = FIH_FAILURE;
-    int fa_id;
     int image_index;
     bool has_upgrade;
 
@@ -2019,14 +1994,10 @@ context_boot_go(struct boot_loader_state *state, struct boot_rsp *rsp)
          * of this call.
          */
         for (slot = 0; slot < BOOT_NUM_SLOTS; slot++) {
-            fa_id = flash_area_id_from_multi_image_slot(image_index, slot);
-            rc = flash_area_open(fa_id, &BOOT_IMG_AREA(state, slot));
-            assert(rc == 0);
+            BOOT_IMG_AREA(state, slot) = flash_area_from_multi_image_slot(image_index, slot);
         }
 #if MCUBOOT_SWAP_USING_SCRATCH
-        rc = flash_area_open(FLASH_AREA_IMAGE_SCRATCH,
-                             &BOOT_SCRATCH_AREA(state));
-        assert(rc == 0);
+        BOOT_SCRATCH_AREA(state) = SCRATCH_FA;
 #endif
 
         /* Determine swap type and complete swap if it has been aborted. */
@@ -2213,8 +2184,6 @@ split_go(int loader_slot, int split_slot, void **entry)
 {
     boot_sector_t *sectors;
     uintptr_t entry_val;
-    int loader_flash_id;
-    int split_flash_id;
     int rc;
     fih_int fih_rc = FIH_FAILURE;
 
@@ -2225,14 +2194,8 @@ split_go(int loader_slot, int split_slot, void **entry)
     BOOT_IMG(&boot_data, loader_slot).sectors = sectors + 0;
     BOOT_IMG(&boot_data, split_slot).sectors = sectors + BOOT_MAX_IMG_SECTORS;
 
-    loader_flash_id = flash_area_id_from_image_slot(loader_slot);
-    rc = flash_area_open(loader_flash_id,
-                         &BOOT_IMG_AREA(&boot_data, loader_slot));
-    assert(rc == 0);
-    split_flash_id = flash_area_id_from_image_slot(split_slot);
-    rc = flash_area_open(split_flash_id,
-                         &BOOT_IMG_AREA(&boot_data, split_slot));
-    assert(rc == 0);
+    BOOT_IMG_AREA(&boot_data, loader_slot) = flash_area_from_image_slot(loader_slot);
+    BOOT_IMG_AREA(&boot_data, split_slot) = flash_area_from_image_slot(split_slot);
 
     /* Determine the sector layout of the image slots and scratch area. */
     rc = boot_read_sectors(&boot_data);
@@ -2577,11 +2540,7 @@ boot_decrypt_and_copy_image_to_sram(struct boot_loader_state *state,
     uint8_t * ram_dst = (void *)(IMAGE_RAM_BASE + img_dst);
 
     image_index = BOOT_CURR_IMG(state);
-    area_id = flash_area_id_from_multi_image_slot(BOOT_CURR_IMG(state), slot);
-    rc = flash_area_open(area_id, &fap_src);
-    if (rc != 0){
-        return BOOT_EFLASH;
-    }
+    fap_src = flash_area_from_multi_image_slot(BOOT_CURR_IMG(state), slot);
 
     tlv_off = BOOT_TLV_OFF(hdr);
 
@@ -2633,8 +2592,6 @@ boot_decrypt_and_copy_image_to_sram(struct boot_loader_state *state,
     rc = 0;
 
 done:
-    flash_area_close(fap_src);
-
     return rc;
 }