diff --git a/bootloader.c b/bootloader.c
index 1e66c3e..b690c55 100644
--- a/bootloader.c
+++ b/bootloader.c
@@ -23,145 +23,103 @@
 #include <stdio.h>
 #include <string.h>
 
-static const char *CACHE_NAME = "CACHE:";
-static const char *MISC_NAME = "MISC:";
+static int get_bootloader_message_mtd(struct bootloader_message *out, const Volume* v);
+static int set_bootloader_message_mtd(const struct bootloader_message *in, const Volume* v);
+static int get_bootloader_message_block(struct bootloader_message *out, const Volume* v);
+static int set_bootloader_message_block(const struct bootloader_message *in, const Volume* v);
 
-#ifdef LOG_VERBOSE
-static void dump_data(const char *data, int len) {
-    int pos;
-    for (pos = 0; pos < len; ) {
-        printf("%05x: %02x", pos, data[pos]);
-        for (++pos; pos < len && (pos % 24) != 0; ++pos) {
-            printf(" %02x", data[pos]);
-        }
-        printf("\n");
+int get_bootloader_message(struct bootloader_message *out) {
+    Volume* v = volume_for_path("/misc");
+    if (strcmp(v->fs_type, "mtd") == 0) {
+        return get_bootloader_message_mtd(out, v);
+    } else if (strcmp(v->fs_type, "emmc") == 0) {
+        return get_bootloader_message_block(out, v);
     }
-}
-#endif
-
-#ifdef USE_EXT4
-// Strictly speaking this doesn't have anything to do with ext4; we
-// really just mean "misc is an emmc partition".  We should have a
-// more configurable way have describing partitions, filesystems, etc.
-
-static const char* MISC_PARTITION =
-    "/dev/block/platform/sdhci-tegra.3/by-name/misc";
-
-int get_bootloader_message(struct bootloader_message* out) {
-    FILE* f = fopen(MISC_PARTITION, "rb");
-    if (f == NULL) {
-        LOGE("Can't open %s\n(%s)\n", MISC_PARTITION, strerror(errno));
-        return -1;
-    }
-    struct bootloader_message temp;
-    int count = fread(&temp, sizeof(temp), 1, f);
-    if (count != 1) {
-        LOGE("Failed reading %s\n(%s)\n", MISC_PARTITION, strerror(errno));
-        return -1;
-    }
-    if (fclose(f) != 0) {
-        LOGE("Failed closing %s\n(%s)\n", MISC_PARTITION, strerror(errno));
-        return -1;
-    }
-    memcpy(out, &temp, sizeof(temp));
-    return 0;
+    LOGE("unknown misc partition fs_type \"%s\"\n", v->fs_type);
+    return -1;
 }
 
-int set_bootloader_message(const struct bootloader_message* in) {
-    FILE* f = fopen(MISC_PARTITION, "wb");
-    if (f == NULL) {
-        LOGE("Can't open %s\n(%s)\n", MISC_PARTITION, strerror(errno));
-        return -1;
+int set_bootloader_message(const struct bootloader_message *in) {
+    Volume* v = volume_for_path("/misc");
+    if (strcmp(v->fs_type, "mtd") == 0) {
+        return set_bootloader_message_mtd(in, v);
+    } else if (strcmp(v->fs_type, "emmc") == 0) {
+        return set_bootloader_message_block(in, v);
     }
-    int count = fwrite(in, sizeof(*in), 1, f);
-    if (count != 1) {
-        LOGE("Failed writing %s\n(%s)\n", MISC_PARTITION, strerror(errno));
-        return -1;
-    }
-    if (fclose(f) != 0) {
-        LOGE("Failed closing %s\n(%s)\n", MISC_PARTITION, strerror(errno));
-        return -1;
-    }
-    return 0;
+    LOGE("unknown misc partition fs_type \"%s\"\n", v->fs_type);
+    return -1;
 }
 
-#else  // MTD partitions
+// ------------------------------
+// for misc partitions on MTD
+// ------------------------------
 
 static const int MISC_PAGES = 3;         // number of pages to save
 static const int MISC_COMMAND_PAGE = 1;  // bootloader command is this page
 
-int get_bootloader_message(struct bootloader_message *out) {
+static int get_bootloader_message_mtd(struct bootloader_message *out,
+                                      const Volume* v) {
     size_t write_size;
-    const MtdPartition *part = get_root_mtd_partition(MISC_NAME);
+    mtd_scan_partitions();
+    const MtdPartition *part = mtd_find_partition_by_name(v->device);
     if (part == NULL || mtd_partition_info(part, NULL, NULL, &write_size)) {
-        LOGE("Can't find %s\n", MISC_NAME);
+        LOGE("Can't find %s\n", v->device);
         return -1;
     }
 
     MtdReadContext *read = mtd_read_partition(part);
     if (read == NULL) {
-        LOGE("Can't open %s\n(%s)\n", MISC_NAME, strerror(errno));
+        LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
         return -1;
     }
 
     const ssize_t size = write_size * MISC_PAGES;
     char data[size];
     ssize_t r = mtd_read_data(read, data, size);
-    if (r != size) LOGE("Can't read %s\n(%s)\n", MISC_NAME, strerror(errno));
+    if (r != size) LOGE("Can't read %s\n(%s)\n", v->device, strerror(errno));
     mtd_read_close(read);
     if (r != size) return -1;
 
-#ifdef LOG_VERBOSE
-    printf("\n--- get_bootloader_message ---\n");
-    dump_data(data, size);
-    printf("\n");
-#endif
-
     memcpy(out, &data[write_size * MISC_COMMAND_PAGE], sizeof(*out));
     return 0;
 }
-
-int set_bootloader_message(const struct bootloader_message *in) {
+static int set_bootloader_message_mtd(const struct bootloader_message *in,
+                                      const Volume* v) {
     size_t write_size;
-    const MtdPartition *part = get_root_mtd_partition(MISC_NAME);
+    mtd_scan_partitions();
+    const MtdPartition *part = mtd_find_partition_by_name(v->device);
     if (part == NULL || mtd_partition_info(part, NULL, NULL, &write_size)) {
-        LOGE("Can't find %s\n", MISC_NAME);
+        LOGE("Can't find %s\n", v->device);
         return -1;
     }
 
     MtdReadContext *read = mtd_read_partition(part);
     if (read == NULL) {
-        LOGE("Can't open %s\n(%s)\n", MISC_NAME, strerror(errno));
+        LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
         return -1;
     }
 
     ssize_t size = write_size * MISC_PAGES;
     char data[size];
     ssize_t r = mtd_read_data(read, data, size);
-    if (r != size) LOGE("Can't read %s\n(%s)\n", MISC_NAME, strerror(errno));
+    if (r != size) LOGE("Can't read %s\n(%s)\n", v->device, strerror(errno));
     mtd_read_close(read);
     if (r != size) return -1;
 
     memcpy(&data[write_size * MISC_COMMAND_PAGE], in, sizeof(*in));
 
-#ifdef LOG_VERBOSE
-    printf("\n--- set_bootloader_message ---\n");
-    dump_data(data, size);
-    printf("\n");
-#endif
-
     MtdWriteContext *write = mtd_write_partition(part);
     if (write == NULL) {
-        LOGE("Can't open %s\n(%s)\n", MISC_NAME, strerror(errno));
+        LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
         return -1;
     }
     if (mtd_write_data(write, data, size) != size) {
-        LOGE("Can't write %s\n(%s)\n", MISC_NAME, strerror(errno));
+        LOGE("Can't write %s\n(%s)\n", v->device, strerror(errno));
         mtd_write_close(write);
         return -1;
     }
     if (mtd_write_close(write)) {
-        LOGE("Can't finish %s\n(%s)\n", MISC_NAME, strerror(errno));
+        LOGE("Can't finish %s\n(%s)\n", v->device, strerror(errno));
         return -1;
     }
 
@@ -169,4 +127,47 @@
     return 0;
 }
 
-#endif
+
+// ------------------------------------
+// for misc partitions on block devices
+// ------------------------------------
+
+static int get_bootloader_message_block(struct bootloader_message *out,
+                                        const Volume* v) {
+    FILE* f = fopen(v->device, "rb");
+    if (f == NULL) {
+        LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+    struct bootloader_message temp;
+    int count = fread(&temp, sizeof(temp), 1, f);
+    if (count != 1) {
+        LOGE("Failed reading %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+    if (fclose(f) != 0) {
+        LOGE("Failed closing %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+    memcpy(out, &temp, sizeof(temp));
+    return 0;
+}
+
+static int set_bootloader_message_block(const struct bootloader_message *in,
+                                        const Volume* v) {
+    FILE* f = fopen(v->device, "wb");
+    if (f == NULL) {
+        LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+    int count = fwrite(in, sizeof(*in), 1, f);
+    if (count != 1) {
+        LOGE("Failed writing %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+    if (fclose(f) != 0) {
+        LOGE("Failed closing %s\n(%s)\n", v->device, strerror(errno));
+        return -1;
+    }
+    return 0;
+}