Factor out fake partition

5 files changed, 120 insertions, 106 deletions

diff --git a/ports/atmel-samd/supervisor/internal_flash.c b/ports/atmel-samd/supervisor/internal_flash.c
index 6e097b214..f1ceb5c92 100644
--- a/ports/atmel-samd/supervisor/internal_flash.c
+++ b/ports/atmel-samd/supervisor/internal_flash.c
@@ -70,7 +70,7 @@ uint32_t supervisor_flash_get_block_size(void) {
 }
 
 uint32_t supervisor_flash_get_block_count(void) {
-    return INTERNAL_FLASH_PART1_START_BLOCK + INTERNAL_FLASH_PART1_NUM_BLOCKS;
+    return INTERNAL_FLASH_PART1_NUM_BLOCKS;
 }
 
 void supervisor_flash_flush(void) {
@@ -80,46 +80,9 @@ void flash_flush(void) {
     supervisor_flash_flush();
 }
 
-static void build_partition(uint8_t *buf, int boot, int type, uint32_t start_block, uint32_t num_blocks) {
-    buf[0] = boot;
-
-    if (num_blocks == 0) {
-        buf[1] = 0;
-        buf[2] = 0;
-        buf[3] = 0;
-    } else {
-        buf[1] = 0xff;
-        buf[2] = 0xff;
-        buf[3] = 0xff;
-    }
-
-    buf[4] = type;
-
-    if (num_blocks == 0) {
-        buf[5] = 0;
-        buf[6] = 0;
-        buf[7] = 0;
-    } else {
-        buf[5] = 0xff;
-        buf[6] = 0xff;
-        buf[7] = 0xff;
-    }
-
-    buf[8] = start_block;
-    buf[9] = start_block >> 8;
-    buf[10] = start_block >> 16;
-    buf[11] = start_block >> 24;
-
-    buf[12] = num_blocks;
-    buf[13] = num_blocks >> 8;
-    buf[14] = num_blocks >> 16;
-    buf[15] = num_blocks >> 24;
-}
-
 static int32_t convert_block_to_flash_addr(uint32_t block) {
-    if (INTERNAL_FLASH_PART1_START_BLOCK <= block && block < INTERNAL_FLASH_PART1_START_BLOCK + INTERNAL_FLASH_PART1_NUM_BLOCKS) {
+    if (0 <= block && block < INTERNAL_FLASH_PART1_NUM_BLOCKS) {
         // a block in partition 1
-        block -= INTERNAL_FLASH_PART1_START_BLOCK;
         return INTERNAL_FLASH_MEM_SEG1_START_ADDR + block * FILESYSTEM_BLOCK_SIZE;
     }
     // bad block
@@ -127,69 +90,44 @@ static int32_t convert_block_to_flash_addr(uint32_t block) {
 }
 
 bool supervisor_flash_read_block(uint8_t *dest, uint32_t block) {
-    if (block == 0) {
-        // fake the MBR so we can decide on our own partition table
-
-        for (int i = 0; i < 446; i++) {
-            dest[i] = 0;
-        }
-
-        build_partition(dest + 446, 0, 0x01 /* FAT12 */, INTERNAL_FLASH_PART1_START_BLOCK, INTERNAL_FLASH_PART1_NUM_BLOCKS);
-        build_partition(dest + 462, 0, 0, 0, 0);
-        build_partition(dest + 478, 0, 0, 0, 0);
-        build_partition(dest + 494, 0, 0, 0, 0);
-
-        dest[510] = 0x55;
-        dest[511] = 0xaa;
-
-        return true;
-
-    } else {
-        // non-MBR block, get data from flash memory
-        int32_t src = convert_block_to_flash_addr(block);
-        if (src == -1) {
-            // bad block number
-            return false;
-        }
-        int32_t error_code = flash_read(&supervisor_flash_desc, src, dest, FILESYSTEM_BLOCK_SIZE);
-        return error_code == ERR_NONE;
+    // non-MBR block, get data from flash memory
+    int32_t src = convert_block_to_flash_addr(block);
+    if (src == -1) {
+        // bad block number
+        return false;
     }
+    int32_t error_code = flash_read(&supervisor_flash_desc, src, dest, FILESYSTEM_BLOCK_SIZE);
+    return error_code == ERR_NONE;
 }
 
 bool supervisor_flash_write_block(const uint8_t *src, uint32_t block) {
-    if (block == 0) {
-        // can't write MBR, but pretend we did
-        return true;
-
-    } else {
-        #ifdef MICROPY_HW_LED_MSC
-            port_pin_set_output_level(MICROPY_HW_LED_MSC, true);
-        #endif
-        temp_status_color(ACTIVE_WRITE);
-        // non-MBR block, copy to cache
-        int32_t dest = convert_block_to_flash_addr(block);
-        if (dest == -1) {
-            // bad block number
-            return false;
-        }
-        int32_t error_code;
-        error_code = flash_erase(&supervisor_flash_desc,
-                                 dest,
-                                 FILESYSTEM_BLOCK_SIZE / flash_get_page_size(&supervisor_flash_desc));
-        if (error_code != ERR_NONE) {
-            return false;
-        }
+    #ifdef MICROPY_HW_LED_MSC
+        port_pin_set_output_level(MICROPY_HW_LED_MSC, true);
+    #endif
+    temp_status_color(ACTIVE_WRITE);
+    // non-MBR block, copy to cache
+    int32_t dest = convert_block_to_flash_addr(block);
+    if (dest == -1) {
+        // bad block number
+        return false;
+    }
+    int32_t error_code;
+    error_code = flash_erase(&supervisor_flash_desc,
+                             dest,
+                             FILESYSTEM_BLOCK_SIZE / flash_get_page_size(&supervisor_flash_desc));
+    if (error_code != ERR_NONE) {
+        return false;
+    }
 
-        error_code = flash_append(&supervisor_flash_desc, dest, src, FILESYSTEM_BLOCK_SIZE);
-        if (error_code != ERR_NONE) {
-            return false;
-        }
-        clear_temp_status();
-        #ifdef MICROPY_HW_LED_MSC
-            port_pin_set_output_level(MICROPY_HW_LED_MSC, false);
-        #endif
-        return true;
+    error_code = flash_append(&supervisor_flash_desc, dest, src, FILESYSTEM_BLOCK_SIZE);
+    if (error_code != ERR_NONE) {
+        return false;
     }
+    clear_temp_status();
+    #ifdef MICROPY_HW_LED_MSC
+        port_pin_set_output_level(MICROPY_HW_LED_MSC, false);
+    #endif
+    return true;
 }
 
 mp_uint_t supervisor_flash_read_blocks(uint8_t *dest, uint32_t block_num, uint32_t num_blocks) {
diff --git a/ports/atmel-samd/supervisor/internal_flash.h b/ports/atmel-samd/supervisor/internal_flash.h
index b1074d93f..0939a3454 100644
--- a/ports/atmel-samd/supervisor/internal_flash.h
+++ b/ports/atmel-samd/supervisor/internal_flash.h
@@ -41,7 +41,6 @@
 #endif
 
 #define INTERNAL_FLASH_MEM_SEG1_START_ADDR (FLASH_SIZE - TOTAL_INTERNAL_FLASH_SIZE - CIRCUITPY_INTERNAL_NVM_SIZE)
-#define INTERNAL_FLASH_PART1_START_BLOCK (0x1)
 #define INTERNAL_FLASH_PART1_NUM_BLOCKS (TOTAL_INTERNAL_FLASH_SIZE / FILESYSTEM_BLOCK_SIZE)
 
 #define INTERNAL_FLASH_SYSTICK_MASK    (0x1ff) // 512ms
diff --git a/ports/nrf/supervisor/internal_flash.h b/ports/nrf/supervisor/internal_flash.h
index adcb9bbc2..cf1dc91b5 100644
--- a/ports/nrf/supervisor/internal_flash.h
+++ b/ports/nrf/supervisor/internal_flash.h
@@ -31,8 +31,6 @@
 
 #include "py/mpconfig.h"
 
-#define FLASH_ROOT_POINTERS
-
 #define FLASH_PAGE_SIZE                 0x1000
 #define CIRCUITPY_INTERNAL_NVM_SIZE     0
 
diff --git a/supervisor/shared/filesystem.c b/supervisor/shared/filesystem.c
index ebbc8c40d..de9af5707 100644
--- a/supervisor/shared/filesystem.c
+++ b/supervisor/shared/filesystem.c
@@ -59,7 +59,7 @@ void filesystem_init(bool create_allowed, bool force_create) {
         // Flush the new file system to make sure it's repaired immediately.
         supervisor_flash_flush();
         if (res != FR_OK) {
-            asm("bkpt");
+            //asm("bkpt");
             return;
         }
 
@@ -75,7 +75,7 @@ void filesystem_init(bool create_allowed, bool force_create) {
         // and ensure everything is flushed
         supervisor_flash_flush();
     } else if (res != FR_OK) {
-        asm("bkpt");
+        //asm("bkpt");
         return;
     }
     mp_vfs_mount_t *vfs = &_mp_vfs;
diff --git a/supervisor/shared/flash.c b/supervisor/shared/flash.c
index 4fa2d8f75..c8921aa85 100644
--- a/supervisor/shared/flash.c
+++ b/supervisor/shared/flash.c
@@ -31,6 +31,8 @@
 
 #define VFS_INDEX 0
 
+#define PART1_START_BLOCK (0x1)
+
 void supervisor_flash_set_usb_writable(bool usb_writable) {
     mp_vfs_mount_t* current_mount = MP_STATE_VM(vfs_mount_table);
     for (uint8_t i = 0; current_mount != NULL; i++) {
@@ -63,10 +65,87 @@ STATIC mp_obj_t supervisor_flash_obj_make_new(const mp_obj_type_t *type, size_t
     return (mp_obj_t)&supervisor_flash_obj;
 }
 
+uint32_t flash_get_block_count(void) {
+    return PART1_START_BLOCK + supervisor_flash_get_block_count();
+}
+
+static void build_partition(uint8_t *buf, int boot, int type, uint32_t start_block, uint32_t num_blocks) {
+    buf[0] = boot;
+
+    if (num_blocks == 0) {
+        buf[1] = 0;
+        buf[2] = 0;
+        buf[3] = 0;
+    } else {
+        buf[1] = 0xff;
+        buf[2] = 0xff;
+        buf[3] = 0xff;
+    }
+
+    buf[4] = type;
+
+    if (num_blocks == 0) {
+        buf[5] = 0;
+        buf[6] = 0;
+        buf[7] = 0;
+    } else {
+        buf[5] = 0xff;
+        buf[6] = 0xff;
+        buf[7] = 0xff;
+    }
+
+    buf[8] = start_block;
+    buf[9] = start_block >> 8;
+    buf[10] = start_block >> 16;
+    buf[11] = start_block >> 24;
+
+    buf[12] = num_blocks;
+    buf[13] = num_blocks >> 8;
+    buf[14] = num_blocks >> 16;
+    buf[15] = num_blocks >> 24;
+}
+
+mp_uint_t flash_read_blocks(uint8_t *dest, uint32_t block_num, uint32_t num_blocks) {
+    if (block_num == 0) {
+        if (block_num > 1) {
+            return 1; // error
+        }
+        // fake the MBR so we can decide on our own partition table
+
+        for (int i = 0; i < 446; i++) {
+            dest[i] = 0;
+        }
+
+        build_partition(dest + 446, 0, 0x01 /* FAT12 */, PART1_START_BLOCK, supervisor_flash_get_block_count());
+        build_partition(dest + 462, 0, 0, 0, 0);
+        build_partition(dest + 478, 0, 0, 0, 0);
+        build_partition(dest + 494, 0, 0, 0, 0);
+
+        dest[510] = 0x55;
+        dest[511] = 0xaa;
+
+        return 0; // ok
+
+    }
+    return supervisor_flash_read_blocks(dest, block_num - PART1_START_BLOCK, num_blocks);
+}
+
+mp_uint_t flash_write_blocks(const uint8_t *src, uint32_t block_num, uint32_t num_blocks) {
+    if (block_num == 0) {
+        if (num_blocks > 1) {
+            return 1; // error
+        }
+        // can't write MBR, but pretend we did
+        return 0;
+    } else {
+        return supervisor_flash_write_blocks(src, block_num - PART1_START_BLOCK, num_blocks);
+    }
+}
+
 STATIC mp_obj_t supervisor_flash_obj_readblocks(mp_obj_t self, mp_obj_t block_num, mp_obj_t buf) {
     mp_buffer_info_t bufinfo;
     mp_get_buffer_raise(buf, &bufinfo, MP_BUFFER_WRITE);
-    mp_uint_t ret = supervisor_flash_read_blocks(bufinfo.buf, mp_obj_get_int(block_num), bufinfo.len / FILESYSTEM_BLOCK_SIZE);
+    mp_uint_t ret = flash_read_blocks(bufinfo.buf, mp_obj_get_int(block_num), bufinfo.len / FILESYSTEM_BLOCK_SIZE);
     return MP_OBJ_NEW_SMALL_INT(ret);
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_3(supervisor_flash_obj_readblocks_obj, supervisor_flash_obj_readblocks);
@@ -74,7 +153,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_3(supervisor_flash_obj_readblocks_obj, supervisor
 STATIC mp_obj_t supervisor_flash_obj_writeblocks(mp_obj_t self, mp_obj_t block_num, mp_obj_t buf) {
     mp_buffer_info_t bufinfo;
     mp_get_buffer_raise(buf, &bufinfo, MP_BUFFER_READ);
-    mp_uint_t ret = supervisor_flash_write_blocks(bufinfo.buf, mp_obj_get_int(block_num), bufinfo.len / FILESYSTEM_BLOCK_SIZE);
+    mp_uint_t ret = flash_write_blocks(bufinfo.buf, mp_obj_get_int(block_num), bufinfo.len / FILESYSTEM_BLOCK_SIZE);
     return MP_OBJ_NEW_SMALL_INT(ret);
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_3(supervisor_flash_obj_writeblocks_obj, supervisor_flash_obj_writeblocks);
@@ -85,7 +164,7 @@ STATIC mp_obj_t supervisor_flash_obj_ioctl(mp_obj_t self, mp_obj_t cmd_in, mp_ob
         case BP_IOCTL_INIT: supervisor_flash_init(); return MP_OBJ_NEW_SMALL_INT(0);
         case BP_IOCTL_DEINIT: supervisor_flash_flush(); return MP_OBJ_NEW_SMALL_INT(0); // TODO properly
         case BP_IOCTL_SYNC: supervisor_flash_flush(); return MP_OBJ_NEW_SMALL_INT(0);
-        case BP_IOCTL_SEC_COUNT: return MP_OBJ_NEW_SMALL_INT(supervisor_flash_get_block_count());
+        case BP_IOCTL_SEC_COUNT: return MP_OBJ_NEW_SMALL_INT(flash_get_block_count());
         case BP_IOCTL_SEC_SIZE: return MP_OBJ_NEW_SMALL_INT(supervisor_flash_get_block_size());
         default: return mp_const_none;
     }
@@ -114,10 +193,10 @@ void supervisor_flash_init_vfs(fs_user_mount_t *vfs) {
     vfs->fatfs.part = 1; // flash filesystem lives on first partition
     vfs->readblocks[0] = (mp_obj_t)&supervisor_flash_obj_readblocks_obj;
     vfs->readblocks[1] = (mp_obj_t)&supervisor_flash_obj;
-    vfs->readblocks[2] = (mp_obj_t)supervisor_flash_read_blocks; // native version
+    vfs->readblocks[2] = (mp_obj_t)flash_read_blocks; // native version
     vfs->writeblocks[0] = (mp_obj_t)&supervisor_flash_obj_writeblocks_obj;
     vfs->writeblocks[1] = (mp_obj_t)&supervisor_flash_obj;
-    vfs->writeblocks[2] = (mp_obj_t)supervisor_flash_write_blocks; // native version
+    vfs->writeblocks[2] = (mp_obj_t)flash_write_blocks; // native version
     vfs->u.ioctl[0] = (mp_obj_t)&supervisor_flash_obj_ioctl_obj;
     vfs->u.ioctl[1] = (mp_obj_t)&supervisor_flash_obj;
 }