diff --git a/fusee/fusee-primary/src/main.c b/fusee/fusee-primary/src/main.c
index ce690aea5..0f9a13ec2 100644
--- a/fusee/fusee-primary/src/main.c
+++ b/fusee/fusee-primary/src/main.c
@@ -92,7 +92,7 @@ int main(void) {
     printk("Please do not seek support for it until it is done.\n");
     generic_panic();
 #endif
-    
+
     /* Try to load the SBK into the security engine, if possible. */
     /* TODO: Should this be done later? */
     load_sbk();
@@ -115,11 +115,10 @@ int main(void) {
     args->lfb = (uint32_t *)lfb_base;
     args->console_col = video_get_col();
     args->console_row = video_get_row();
-    save_sd_state(&args->sd_mmc, &args->sd_fs);
-
+    save_sd_state(&args->sd_mmc);
+    f_unmount("");
 
     /* Jump to Stage 2. */
     stage2_entrypoint(STAGE2_ARGC, stage2_argv);
     return 0;
 }
-
diff --git a/fusee/fusee-primary/src/sd_utils.c b/fusee/fusee-primary/src/sd_utils.c
index 965ad2f01..2f590c394 100644
--- a/fusee/fusee-primary/src/sd_utils.c
+++ b/fusee/fusee-primary/src/sd_utils.c
@@ -10,15 +10,13 @@ FATFS sd_fs;
 static int initialized_sd = 0;
 static int mounted_sd = 0;
 
-void save_sd_state(void **mmc, void **ff) {
+void save_sd_state(void **mmc) {
     *mmc = &sd_mmc;
-    *ff = &ff;
 }
-void resume_sd_state(void *mmc, void *ff) {
+
+void resume_sd_state(void *mmc) {
     sd_mmc = *(struct mmc *)mmc;
-    sd_fs = *(FATFS *)ff;
     initialized_sd = 1;
-    mounted_sd = 1;
 }
 
 int initialize_sd(void) {
diff --git a/fusee/fusee-primary/src/sd_utils.h b/fusee/fusee-primary/src/sd_utils.h
index 11401335c..095adf2d9 100644
--- a/fusee/fusee-primary/src/sd_utils.h
+++ b/fusee/fusee-primary/src/sd_utils.h
@@ -5,8 +5,8 @@
 #include "sdmmc.h"
 #include "lib/fatfs/ff.h"
 
-void save_sd_state(void **mmc, void **ff);
-void resume_sd_state(void *mmc, void *ff);
+void save_sd_state(void **mmc);
+void resume_sd_state(void *mmc);
 
 size_t read_sd_file(void *dst, size_t dst_size, const char *filename);
 
diff --git a/fusee/fusee-primary/src/stage2.h b/fusee/fusee-primary/src/stage2.h
index 612f7bdbb..4d2ef4932 100644
--- a/fusee/fusee-primary/src/stage2.h
+++ b/fusee/fusee-primary/src/stage2.h
@@ -27,10 +27,9 @@ typedef struct {
     uint32_t console_row;
     uint32_t console_col;
     void *sd_mmc;
-    void *sd_fs;
 } stage2_args_t;
 
 const char *stage2_get_program_path(void);
 stage2_entrypoint_t load_stage2(const char *bct0);
 
-#endif
\ No newline at end of file
+#endif
diff --git a/fusee/fusee-secondary/src/loader.c b/fusee/fusee-secondary/src/loader.c
index 9671573f5..2866197f0 100644
--- a/fusee/fusee-secondary/src/loader.c
+++ b/fusee/fusee-secondary/src/loader.c
@@ -19,7 +19,7 @@ static int loadlist_entry_ini_handler(void *user, const char *section, const cha
     load_file_t *load_file_ctx = (load_file_t *)user;
     uintptr_t x = 0;
     const char *ext = NULL;
-    
+
     if (strcmp(section, "stage2") == 0) {
         if (strstr(name, load_file_ctx->key) == name) {
             ext = name + strlen(load_file_ctx->key);
@@ -51,33 +51,33 @@ bool validate_load_address(uintptr_t load_addr) {
 void load_list_entry(const char *key) {
     load_file_t load_file_ctx = {0};
     load_file_ctx.key = key;
-    
+
     printk("Loading %s\n", key);
-    
+
     if (ini_parse_string(get_loader_ctx()->bct0, loadlist_entry_ini_handler, &load_file_ctx) < 0) {
         printk("Error: Failed to parse BCT.ini!\n");
         generic_panic();
     }
-    
+
     if (load_file_ctx.load_address == 0 || load_file_ctx.path[0] == '\x00') {
         printk("Error: Failed to determine where to load %s!\n", key);
         generic_panic();
     }
-    
+
     printk("Loading %s from %s to 0x%08x\n", key, load_file_ctx.path, load_file_ctx.load_address);
-    
+
     if (!validate_load_address(load_file_ctx.load_address)) {
         printk("Error: Load address 0x%08x is invalid!\n");
         generic_panic();
     }
-    
+
     /* Read file off of SD. */
     load_file_ctx.load_size = read_sd_file((void *)load_file_ctx.load_address, LOADER_FILESIZE_MAX, load_file_ctx.path);
     if (load_file_ctx.load_size == 0) {
         printk("Error: Failed to read %s!\n", load_file_ctx.path);
         generic_panic();
     }
-    
+
     /* Check for special keys. */
     if (strcmp(key, LOADER_PACKAGE2_KEY) == 0) {
         get_loader_ctx()->package2_loadfile = load_file_ctx;
@@ -92,26 +92,26 @@ void load_list_entry(const char *key) {
 
 void parse_loadlist(const char *ll) {
     printk("Parsing load list: %s\n", ll);
-    
+
     char load_list[0x200] = {0};
     strncpy(load_list, ll, 0x200);
-    
+
     char *entry, *p;
-    
+
     /* entry will point to the start of the current entry. p will point to the current location in the list. */
     entry = load_list;
     p = load_list;
-    
+
     while (*p) {
         if (*p == ' ' || *p == '\t') {
             /* We're at the end of an entry. */
             *p = '\x00';
-            
+
             /* Load the entry. */
             load_list_entry(entry);
             /* Skip to the next delimiter. */
             for (; *p == ' ' || *p == '\t' || *p == '\x00'; p++) { }
-            if (*p != '|') { 
+            if (*p != '|') {
                 printk("Error: Load list is malformed!\n");
                 generic_panic();
             } else {
@@ -132,7 +132,7 @@ void parse_loadlist(const char *ll) {
 static int loadlist_ini_handler(void *user, const char *section, const char *name, const char *value) {
     loader_ctx_t *loader_ctx = (loader_ctx_t *)user;
     uintptr_t x = 0;
-    
+
     if (strcmp(section, "stage2") == 0) {
         if (strcmp(name, LOADER_LOADLIST_KEY) == 0) {
             parse_loadlist(value);
@@ -153,12 +153,12 @@ static int loadlist_ini_handler(void *user, const char *section, const char *nam
 
 void load_payload(const char *bct0) {
     loader_ctx_t *ctx = get_loader_ctx();
-    
+
     /* Set BCT0 global. */
     ctx->bct0 = bct0;
-    
+
     if (ini_parse_string(ctx->bct0, loadlist_ini_handler, ctx) < 0) {
         printk("Error: Failed to parse BCT.ini!\n");
         generic_panic();
     }
-}
\ No newline at end of file
+}
diff --git a/fusee/fusee-secondary/src/main.c b/fusee/fusee-secondary/src/main.c
index 38cb78f42..2c7e9a904 100644
--- a/fusee/fusee-secondary/src/main.c
+++ b/fusee/fusee-secondary/src/main.c
@@ -6,6 +6,7 @@
 #include "sd_utils.h"
 #include "lib/printk.h"
 #include "display/video_fb.h"
+#include "fs_dev.h"
 
 /* TODO: Add a #define for this size, somewhere. Also, primary can only actually load 0x7000. */
 char g_bct0[0x8000];
@@ -30,7 +31,9 @@ int main(int argc, void **argv) {
         generic_panic();
     }
 
-    resume_sd_state((struct mmc *)args.sd_mmc, (FATFS *)args.sd_fs);
+    resume_sd_state((struct mmc *)args.sd_mmc);
+    fsdev_mount_all();
+    fsdev_set_default_device("sdmc");
 
     /* Copy the BCT0 from unsafe primary memory into our memory. */
     strncpy(g_bct0, args.bct0, sizeof(g_bct0));
@@ -48,6 +51,9 @@ int main(int argc, void **argv) {
 
     printk("Loaded payloads!\n");
 
+    /* Unmount everything (this causes all open files to be flushed and closed) */
+    fsdev_unmount_all();
+
     if (loader_ctx->chainload_entrypoint != NULL) {
         /* TODO: What do we want to do in terms of argc/argv? */
         loader_ctx->chainload_entrypoint(0, NULL);
diff --git a/fusee/fusee-secondary/src/sd_utils.c b/fusee/fusee-secondary/src/sd_utils.c
index 965ad2f01..47c4dc34e 100644
--- a/fusee/fusee-secondary/src/sd_utils.c
+++ b/fusee/fusee-secondary/src/sd_utils.c
@@ -1,3 +1,4 @@
+#include <stdio.h>
 #include "sd_utils.h"
 #include "hwinit.h"
 #include "sdmmc.h"
@@ -6,19 +7,14 @@
 
 /* This is used by diskio.h. */
 struct mmc sd_mmc;
-FATFS sd_fs;
 static int initialized_sd = 0;
-static int mounted_sd = 0;
 
-void save_sd_state(void **mmc, void **ff) {
+void save_sd_state(void **mmc) {
     *mmc = &sd_mmc;
-    *ff = &ff;
 }
-void resume_sd_state(void *mmc, void *ff) {
+void resume_sd_state(void *mmc) {
     sd_mmc = *(struct mmc *)mmc;
-    sd_fs = *(FATFS *)ff;
     initialized_sd = 1;
-    mounted_sd = 1;
 }
 
 int initialize_sd(void) {
@@ -33,33 +29,13 @@ int initialize_sd(void) {
     return initialized_sd;
 }
 
-int mount_sd(void) {
-    if (mounted_sd) {
-        return 1;
-    }
-    if (f_mount(&sd_fs, "", 1) == FR_OK) {
-        printk("Mounted SD card!\n");
-        mounted_sd = 1;
-    }
-    return mounted_sd;
-}
-
 size_t read_sd_file(void *dst, size_t dst_size, const char *filename) {
-    if (!initialized_sd && initialize_sd() == 0) {
+    FILE *file = fopen(filename, "rb");
+    if (file == NULL) {
         return 0;
+    } else {
+        size_t sz = fread(dst, 1, dst_size, file);
+        fclose(file);
+        return sz;
     }
-    if (!mounted_sd && mount_sd() == 0) {
-        return 0;
-    }
-
-    FIL f;
-    if (f_open(&f, filename, FA_READ) != FR_OK) {
-        return 0;
-    }
-
-    UINT br;
-    int res = f_read(&f, dst, dst_size, &br);
-    f_close(&f);
-
-    return res == FR_OK ? (int)br : 0;
 }
diff --git a/fusee/fusee-secondary/src/sd_utils.h b/fusee/fusee-secondary/src/sd_utils.h
index 11401335c..d793ccbbc 100644
--- a/fusee/fusee-secondary/src/sd_utils.h
+++ b/fusee/fusee-secondary/src/sd_utils.h
@@ -3,10 +3,9 @@
 
 #include "utils.h"
 #include "sdmmc.h"
-#include "lib/fatfs/ff.h"
 
-void save_sd_state(void **mmc, void **ff);
-void resume_sd_state(void *mmc, void *ff);
+void save_sd_state(void **mmc);
+void resume_sd_state(void *mmc);
 
 size_t read_sd_file(void *dst, size_t dst_size, const char *filename);
 
diff --git a/fusee/fusee-secondary/src/splash_screen.c b/fusee/fusee-secondary/src/splash_screen.c
index 4768b5d00..3170d5b80 100644
--- a/fusee/fusee-secondary/src/splash_screen.c
+++ b/fusee/fusee-secondary/src/splash_screen.c
@@ -6,16 +6,16 @@
 #include "display/video_fb.h"
 
 void display_splash_screen_bmp(const char *custom_splash_path) {
-    unsigned char *splash_screen = g_default_splash_screen;
+    uint8_t *splash_screen = g_default_splash_screen;
     if (custom_splash_path != NULL && custom_splash_path[0] != '\x00') {
         if (!read_sd_file(splash_screen, sizeof(g_default_splash_screen), custom_splash_path)) {
             printk("Error: Failed to read custom splash screen from %s!\n", custom_splash_path);
             generic_panic();
         }
     }
-    
+
     /* TODO: Display the splash screen. It should be a pointer to a BMP, at this point. */
-    
+
     /* Display the splash screen for three seconds. */
     wait(3000000);
-}
\ No newline at end of file
+}
diff --git a/fusee/fusee-secondary/src/splash_screen.h b/fusee/fusee-secondary/src/splash_screen.h
index 7e3352196..7240b3235 100644
--- a/fusee/fusee-secondary/src/splash_screen.h
+++ b/fusee/fusee-secondary/src/splash_screen.h
@@ -1,9 +1,11 @@
 #ifndef FUSEE_SPLASH_SCREEN_H
 #define FUSEE_SPLASH_SCREEN_H
 
+#include <stdint.h>
+
 /* TODO: Actually make this a real thing. */
 extern unsigned char g_default_splash_screen[1];
 
 void display_splash_screen_bmp(const char *custom_splash_path);
 
-#endif
\ No newline at end of file
+#endif
diff --git a/fusee/fusee-secondary/src/splash_screen_default.c b/fusee/fusee-secondary/src/splash_screen_default.c
index 40555dc4c..c1391a6cf 100644
--- a/fusee/fusee-secondary/src/splash_screen_default.c
+++ b/fusee/fusee-secondary/src/splash_screen_default.c
@@ -1,3 +1,3 @@
 #include "splash_screen.h"
 
-unsigned char g_default_splash_screen[1] = {0};
\ No newline at end of file
+uint8_t g_default_splash_screen[1] = {0};
diff --git a/fusee/fusee-secondary/src/stage2.h b/fusee/fusee-secondary/src/stage2.h
index c0bb0bbc4..65cc70657 100644
--- a/fusee/fusee-secondary/src/stage2.h
+++ b/fusee/fusee-secondary/src/stage2.h
@@ -15,7 +15,6 @@ typedef struct {
     uint32_t console_row;
     uint32_t console_col;
     void *sd_mmc;
-    void *sd_fs;
 } stage2_args_t;
 
-#endif
\ No newline at end of file
+#endif