updater: Can now perform a "dangerous update" which overwrites the partition table and do raw flash writes

The updater will first attempt a standard update: If the partition table hasn't changed too much, then partitions can be updated individually.

If the partition table HAS changed too much then the partition table will be overwritten and apps blindly written to flash.

Still lots of work to do to make it foolproof, and more flexible.

Author: ducalex

updater/main/main.c

@@ -14,7 +14,6 @@
 // CONFIG_SPI_FLASH_DANGEROUS_WRITE_ALLOWED
 
 #define MAX_PARTITIONS (24) // ESP_PARTITION_TABLE_MAX_ENTRIES
-#define ALIGN_BLOCK(val, alignment) ((int)(((val) + (alignment - 1)) / alignment) * alignment)
 
 #define RETRO_GO_IMG_MAGIC "RG_IMG_0"
 typedef struct
@@ -35,7 +34,7 @@ typedef struct
     struct {int offset, size;} dst;
 } flash_task_t;
 
-static size_t gp_buffer_size = 0x20000;
+static size_t gp_buffer_size = 0x10000;
 static void *gp_buffer = NULL;
 static rg_app_t *app;
 
@@ -47,6 +46,8 @@ static rg_app_t *app;
         rg_gui_alert(_("Error"), FORMAT(error_message)); \
         goto fail;                                       \
     }
+#define ALIGN_BLOCK(val, alignment) ((int)(((val) + (alignment - 1)) / alignment) * alignment)
+#define CHECK_OVERLAP(start1, end1, start2, end2) ((end1) > (start2) && (end2) > (start1))
 
 static bool fread_at(void *output, int offset, int length, FILE *fp)
 {
@@ -159,11 +160,6 @@ static bool do_flash(flash_task_t *queue, size_t queue_count, FILE *fp)
     return false;
 }
 
-static bool do_update_dangerous(const char *filename)
-{
-    return false;
-}
-
 static bool do_update(const char *filename)
 {
     esp_partition_info_t partition_table[MAX_PARTITIONS] = {0};
@@ -180,43 +176,94 @@ static bool do_update(const char *filename)
     if (!parse_file(partition_table, &num_partitions, fp))
         goto fail;
 
-    const char *current_partition = esp_ota_get_running_partition()->label;
-    // At this time we only flash partitions of type app and subtype ota_X
+    const esp_partition_t *running_partition = esp_ota_get_running_partition();
+    const esp_partition_t *factory_partition = esp_partition_find_first(0x00, 0x00, NULL);
+    bool dangerous = false;
+
+    RG_LOGW("Checking if we can perform a standard update...");
+    size_t updatable_partitions = 0;
     for (size_t i = 0; i < num_partitions; ++i)
     {
         const esp_partition_info_t *src = &partition_table[i];
         const esp_partition_t *dst = esp_partition_find_first(src->type, ESP_PARTITION_SUBTYPE_ANY, (char *)src->label);
 
         if (src->type != PART_TYPE_APP || (src->subtype & 0xF0) != PART_SUBTYPE_OTA_FLAG)
             RG_LOGW("Skipping partition %.16s: Unsupported type.", (char *)src->label);
-        else if (!dst)
-            RG_LOGW("Skipping partition %.16s: No match found.", (char *)src->label);
-        else if ((dst->subtype & 0xF0) != PART_SUBTYPE_OTA_FLAG)
-            RG_LOGW("Skipping partition %.16s: Not an OTA partition.", (char *)src->label);
-        else if (strncmp(current_partition, dst->label, 16) == 0)
+        else if (dst == running_partition)
             RG_LOGW("Skipping partition %.16s: Currently running.", (char *)src->label);
-        else if (dst->size < src->pos.size)
-            RG_LOGW("Skipping partition %.16s: New partition is bigger.", (char *)src->label);
         else
         {
-            RG_LOGI("Partition %.16s can be updated!", (char *)src->label);
-            flash_task_t *task = memset(&queue[queue_count++], 0, sizeof(flash_task_t));
-            memcpy(task->name, src->label, 16);
-            task->src.offset = src->pos.offset;
-            task->src.size = src->pos.size;
-            task->dst.offset = dst->address;
-            task->dst.size = dst->size;
+            updatable_partitions++;
+            if (!dst)
+                RG_LOGW("Skipping partition %.16s: No match found.", (char *)src->label);
+            else if (dst->size < src->pos.size)
+                RG_LOGW("Skipping partition %.16s: New partition is bigger.", (char *)src->label);
+            else
+            {
+                RG_LOGI("Partition %.16s can be updated!", (char *)src->label);
+                flash_task_t *task = memset(&queue[queue_count++], 0, sizeof(flash_task_t));
+                memcpy(task->name, src->label, 16);
+                task->src.offset = src->pos.offset;
+                task->src.size = src->pos.size;
+                task->dst.offset = dst->address;
+                task->dst.size = dst->size;
+            }
         }
     }
 
-    rg_display_clear(C_BLACK);
+    if (updatable_partitions != queue_count)
+    {
+        // Some partitions can't be updated with this method, we have to attempt a dangerous update instead!
+        RG_LOGW("Some partitions cannot be updated in this mode. updatable_partitions=%d, queue_count=%d",
+            updatable_partitions, queue_count);
+    #if CONFIG_SPI_FLASH_DANGEROUS_WRITE_ALLOWED
+        // The presence of a factory app that is NOT the current app indicates that we're controlled by
+        // odroid-go-firmware or odroid-go-multifirmware and it isn't safe to do arbitrary flash writes
+        if (factory_partition && factory_partition != running_partition)
+            rg_gui_alert(_("Error"), "Probably running under odroid-go-multifirmware, cannot do full update!");
+        else
+            dangerous = true;
+    #else
+        rg_gui_alert(_("Error"), "CONFIG_SPI_FLASH_DANGEROUS_WRITE_ALLOWED is not set, cannot do full update!\n");
+    #endif
+    }
 
-    if (queue_count == 0)
+    if (dangerous)
     {
-        // Try dangerous update
-        // goto fail;
+        RG_LOGW("Performing a dangerous update!");
+        queue_count = 0;
+        for (size_t i = 0; i < num_partitions; ++i)
+        {
+            const esp_partition_info_t *src = &partition_table[i];
+            if (src->type != PART_TYPE_APP || (src->subtype & 0xF0) != PART_SUBTYPE_OTA_FLAG)
+                RG_LOGW("Skipping partition %.16s: Unsupported type.", (char *)src->label);
+            else if (src->pos.offset < 0x10000)
+                RG_LOGW("Skipping partition %.16s: Forbidden region.", (char *)src->label);
+            // FIXME: Instead of skipping an overlaping partition, we should attempt to relocate it.
+            else if (CHECK_OVERLAP(src->pos.offset, src->pos.offset + src->pos.size,
+                                running_partition->address, running_partition->address + running_partition->size))
+                RG_LOGW("Skipping partition %.16s: Overlap with self.", (char *)src->label);
+            else
+            {
+                RG_LOGI("Partition %.16s can be updated!", (char *)src->label);
+                flash_task_t *task = memset(&queue[queue_count++], 0, sizeof(flash_task_t));
+                memcpy(task->name, src->label, 16);
+                task->src.offset = src->pos.offset;
+                task->src.size = src->pos.size;
+                task->dst.offset = src->pos.offset;
+                task->dst.size = src->pos.size;
+            }
+        }
+
+        queue[queue_count++] = (flash_task_t){
+            .name = "partition_table",
+            .src = {ESP_PARTITION_TABLE_OFFSET, ESP_PARTITION_TABLE_MAX_LEN},
+            .dst = {ESP_PARTITION_TABLE_OFFSET, ESP_PARTITION_TABLE_MAX_LEN},
+        };
     }
 
+    rg_display_clear(C_BLACK);
+
     if (!do_flash(queue, queue_count, fp))
         goto fail;