Support for booting from eMMC

Fusee will Look for FAT32 partition on BOOT1 (1MB offset), BOOT1, GPP, SD, in this order
If a .no_boot_storage file is found in the root directory, the partition is skipped

fusee/program/source/fatfs/diskio.c

@@ -15,6 +15,8 @@
 
 #include "diskio_cpp.h"
 
+#define BOOT1_OFFSET_SCT_1MB 0x800
+
 /*-----------------------------------------------------------------------*/
 /* Get Drive Status                                                      */
 /*-----------------------------------------------------------------------*/
@@ -57,6 +59,11 @@ DRESULT disk_read (
             return diskio_read_sd_card(buff, count * 512, sector, count) ? RES_OK : RES_ERROR;
         case DRIVE_SYS:
             return diskio_read_system(buff, count * 512, sector, count) ? RES_OK : RES_ERROR;
+        case DRIVE_BOOT1:
+            return diskio_read_boot1(buff, count * 512, sector, count) ? RES_OK : RES_ERROR;
+        case DRIVE_BOOT1_OFF:
+            return diskio_read_boot1(buff, count * 512, sector + BOOT1_OFFSET_SCT_1MB, count) ? RES_OK : RES_ERROR;
+
         default:
             return RES_PARERR;
     }
@@ -82,6 +89,10 @@ DRESULT disk_write (
             return diskio_write_sd_card(sector, count, buff, count * 512) ? RES_OK : RES_ERROR;
         case DRIVE_SYS:
             return diskio_write_system(sector, count, buff, count * 512) ? RES_OK : RES_ERROR;
+        case DRIVE_BOOT1:
+            return diskio_write_boot1(sector, count, buff, count * 512) ? RES_OK : RES_ERROR;
+        case DRIVE_BOOT1_OFF:
+            return diskio_write_boot1(sector + DRIVE_BOOT1_OFF, count, buff, count * 512) ? RES_OK : RES_ERROR;
         default:
             return RES_PARERR;
     }

fusee/program/source/fatfs/diskio.h

@@ -25,6 +25,8 @@ typedef enum {
 typedef enum {
     DRIVE_SD,
     DRIVE_SYS,
+    DRIVE_BOOT1,
+    DRIVE_BOOT1_OFF,
 } DDRIVE;
 
 

fusee/program/source/fatfs/diskio_cpp.h

@@ -25,6 +25,9 @@ bool diskio_write_sd_card(size_t sector_index, size_t sector_count, const void *
 bool diskio_read_system(void *dst, size_t size, size_t sector_index, size_t sector_count);
 bool diskio_write_system(size_t sector_index, size_t sector_count, const void *src, size_t size);
 
+bool diskio_read_boot1(void *dst, size_t size, size_t sector_index, size_t sector_count);
+bool diskio_write_boot1(size_t sector_index, size_t sector_count, const void *src, size_t size);
+
 #ifdef __cplusplus
 }
 #endif

fusee/program/source/fatfs/ffconf.h

@@ -150,7 +150,7 @@
 */
 
 
-#define FF_FS_RPATH     0
+#define FF_FS_RPATH     1
 /* This option configures support for relative path.
 /
 /   0: Disable relative path and remove related functions.
@@ -163,12 +163,12 @@
 / Drive/Volume Configurations
 /---------------------------------------------------------------------------*/
 
-#define FF_VOLUMES      2
+#define FF_VOLUMES      4
 /* Number of volumes (logical drives) to be used. (1-10) */
 
 
 #define FF_STR_VOLUME_ID    1
-#define FF_VOLUME_STRS      "sdmc","sys"
+#define FF_VOLUME_STRS      "sdmc","sys","boot1","boot1_off"
 /* FF_STR_VOLUME_ID switches support for volume ID in arbitrary strings.
 /  When FF_STR_VOLUME_ID is set to 1 or 2, arbitrary strings can be used as drive
 /  number in the path name. FF_VOLUME_STRS defines the volume ID strings for each

fusee/program/source/fatfs/fusee_diskio.cpp

@@ -33,4 +33,13 @@ bool diskio_read_system(void *dst, size_t size, size_t sector_index, size_t sect
 bool diskio_write_system(size_t sector_index, size_t sector_count, const void *src, size_t size) {
     /* Don't allow writes to eMMC GPP partition */
     return false;
+}
+
+bool diskio_read_boot1(void *dst, size_t size, size_t sector_index, size_t sector_count) {
+    return R_SUCCEEDED(::ams::nxboot::ReadMmc(dst, size, ::ams::sdmmc::MmcPartition::MmcPartition_BootPartition2, sector_index, sector_count));
+}
+
+bool diskio_write_boot1(size_t sector_index, size_t sector_count, const void *src, size_t size) {
+    /* Don't allow writes to eMMC BOOT1 */
+    return false;
 }