allow emmc writes (to write warmboot to emusd), allow unaligned emmc writes

fusee/program/source/fatfs/fusee_diskio.cpp

@@ -32,8 +32,7 @@ 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;
+    return R_SUCCEEDED(::ams::nxboot::WriteMmc(::ams::sdmmc::MmcPartition::MmcPartition_UserData, sector_index, sector_count, src, size));
 }
 
 bool diskio_read_boot1(void *dst, size_t size, size_t sector_index, size_t sector_count) {

fusee/program/source/fs/fusee_fs_storage.hpp

@@ -241,7 +241,7 @@ namespace ams::fs {
             private:
                 void EnsureFile(int id);
             public:
-                MultiFileStorage(const char *base_path);
+                MultiFileStorage(const char *base_path, OpenMode mode);
                 virtual Result Read(s64 offset, void *buffer, size_t size) override;
                 virtual Result Flush() override;
                 virtual Result GetSize(s64 *out) override;

fusee/program/source/fs/fusee_multi_file_storage.cpp

@@ -34,7 +34,7 @@ namespace ams::fs {
             }
         }
 
-        MultiFileStorage::MultiFileStorage(const char *base_path) {
+        MultiFileStorage::MultiFileStorage(const char *base_path, fs::OpenMode mode) {
             util::Strlcpy(m_base_path, base_path, sizeof(m_base_path) - 2);
             m_file_path_ofs = strlen(m_base_path);
 
@@ -44,7 +44,7 @@ namespace ams::fs {
 
             std::memcpy(m_base_path + m_file_path_ofs, "00", 3);
             Result r;
-            if (R_FAILED(r = fs::OpenFile(std::addressof(m_handles[0]), m_base_path, fs::OpenMode_Read))) {
+            if (R_FAILED(r = fs::OpenFile(std::addressof(m_handles[0]), m_base_path, mode))) {
                 nxboot::ShowFatalError("Failed to open part %02d (%s): 0x%08" PRIx32 "!\n", 0, m_base_path, r.GetValue());
             }
             

fusee/program/source/fusee_emummc.cpp

@@ -191,7 +191,7 @@ namespace ams::nxboot {
                 /* Create partition */
                 /* TODO: construct boot0 storage from path instead */
                 g_boot0_storage = AllocateObject<fs::FileHandleStorage>(boot0_file);
-                g_user_storage  = AllocateObject<EmummcFileStorage>(path);
+                g_user_storage  = AllocateObject<EmummcFileStorage>(path, fs::OpenMode_Read);
             } else {
                 ShowFatalError("Unknown emummc type %d\n", static_cast<int>(emummc_cfg.base_cfg.type));
             }

fusee/program/source/fusee_emusd.cpp

@@ -117,7 +117,7 @@ namespace ams::nxboot {
                 memcpy(path + strlen(path), "/SD/", 5);
                 path[sizeof(path) - 1] = '\x00';
 
-                g_emusd_storage = AllocateObject<fs::MultiFileStorage>(path);
+                g_emusd_storage = AllocateObject<fs::MultiFileStorage>(path, fs::OpenMode_ReadWrite);
             } else {
                 ShowFatalError("Invalid emuSD config!\n");
             }

fusee/program/source/fusee_setup_horizon.cpp

@@ -622,7 +622,7 @@ namespace ams::nxboot {
 
         /* Determine whether we're using emummc. */
         const bool emummc_driver_enabled = ConfigureEmummc();
-        const bool emummc_enabled = GetEmummcConfig().emmc_cfg.IsActive();
+        const bool emummc_enabled        = GetEmummcConfig().emmc_cfg.IsActive();
 
         /* Initialize emummc. */
         /* NOTE: SYSTEM:/ accessible past this point. */

libraries/libvapours/source/sdmmc/impl/sdmmc_mmc_device_accessor.cpp

@@ -498,17 +498,16 @@ namespace ams::sdmmc::impl {
     Result MmcDeviceAccessor::OnReadWrite(u32 sector_index, u32 num_sectors, void *buf, size_t buf_size, bool is_read) {
         /* Get the sector index alignment. */
         u32 sector_index_alignment = 0;
+
+        /* Allow unaligned writes for exosphere/fusee */
+        /* TODO: bad */
+        #ifndef ATMOSPHERE_IS_EXOSPHERE
         if (!is_read) {
-            #ifdef ATMOSPHERE_IS_EXOSPHERE
-            /* Allow unaligned writes */
-            /* TODO: bad */
-            constexpr u32 MmcWriteSectorAlignment = 0;
-            #else 
             constexpr u32 MmcWriteSectorAlignment = 16_KB / SectorSize;
-            #endif
             sector_index_alignment = MmcWriteSectorAlignment;
             AMS_ABORT_UNLESS(util::IsAligned(sector_index, MmcWriteSectorAlignment));
         }
+        #endif
 
         /* Do the read/write. */
         R_RETURN(BaseDeviceAccessor::ReadWriteMultiple(sector_index, num_sectors, sector_index_alignment, buf, buf_size, is_read));