8 files changed, 167 insertions, 59 deletions

diff --git a/firmware/common/rb-loader.c b/firmware/common/rb-loader.c
index 82b636d451..8bf553a3a8 100644
--- a/firmware/common/rb-loader.c
+++ b/firmware/common/rb-loader.c
@@ -7,6 +7,7 @@
  *                     \/            \/     \/    \/            \/
  *
  * Copyright (C) 2005 by Linus Nielsen Feltzing
+ * Copyright (C) 2017 by William Wilgus
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -22,18 +23,16 @@
 #include "config.h"
 #include "system.h"
 #include "file.h"
-#include "rb-loader.h"
 #include "loader_strerror.h"
 
 #if defined(HAVE_BOOTDATA)
 #include "bootdata.h"
 #include "crc32.h"
 
-/* Write boot data into location marked by magic header
- * buffer is already loaded with the firmware image
- * we just need to find the location and write
- * data into the payload along with the crc
- * for later verification and use.
+/* Write bootdata into location in FIRMWARE marked by magic header
+ * Assumes buffer is already loaded with the firmware image
+ * We just need to find the location and write data into the
+ * payload region along with the crc for later verification and use.
  * Returns payload len on success,
  * On error returns EKEY_NOT_FOUND
  */
@@ -51,68 +50,92 @@ static int write_bootdata(unsigned char* buf, int len, unsigned int boot_volume)
         if (fw_boot_data->magic[0] != BOOT_DATA_MAGIC0 ||
             fw_boot_data->magic[1] != BOOT_DATA_MAGIC1)
             continue;
-        /* 0 fill bootloader struct then add our data */
+
         memset(&bl_boot_data.payload, 0, BOOT_DATA_PAYLOAD_SIZE);
         bl_boot_data.boot_volume = boot_volume;
-        /* 0 fill payload region in firmware */
+
         memset(fw_boot_data->payload, 0, fw_boot_data->length);
         /* determine maximum bytes we can write to firmware
            BOOT_DATA_PAYLOAD_SIZE is the size the bootloader expects */
         payload_len = MIN(BOOT_DATA_PAYLOAD_SIZE, fw_boot_data->length);
-        /* write payload size back to firmware struct */
         fw_boot_data->length = payload_len;
-        /* copy data to firmware bootdata struct */
+        /* copy data to FIRMWARE bootdata struct */
         memcpy(fw_boot_data->payload, &bl_boot_data.payload, payload_len);
-        /* calculate and write the crc for the payload */
-        fw_boot_data->crc = crc_32(fw_boot_data->payload,
-                                   payload_len,
-                                   0xffffffff);
+        /* crc will be used within the firmware to check validity of bootdata */
+        fw_boot_data->crc = crc_32(fw_boot_data->payload, payload_len, 0xffffffff);
         break;
 
     }
     return payload_len;
 }
 #endif /* HAVE_BOOTDATA */
-/* Load firmware image in a format created by add method of tools/scramble
- * on success we return size loaded image
- * on error we return negative value which can be deciphered by means
- * of strerror() function
+
+#ifdef HAVE_MULTIBOOT /* defined by config.h */
+/* Check in root of this <volume> for rockbox_main.<playername>
+ * if this file empty or there is a single slash '/'
+ * buf = '<volume#>/<rootdir>/<firmware(name)>\0'
+ * If instead '/<*DIRECTORY*>' is supplied
+ * addpath will be set to this DIRECTORY buf =
+ * '/<volume#>/addpath/<rootdir>/<firmware(name)>\0'
+ * On error returns Negative number or 0
+ * On success returns bytes from snprintf
+ * and generated path will be placed in buf
+ * note: if supplied buffer is too small return will be
+ * the number of bytes that would have been written
  */
-int load_firmware(unsigned char* buf, const char* firmware, int buffer_size)
+int get_redirect_dir(char* buf, int buffer_size, int volume,
+                     const char* rootdir, const char* firmware)
 {
-    char filename[MAX_PATH];
     int fd;
-    int rc;
-    int len;
-    int ret = 0;
-    unsigned long chksum;
-    unsigned long sum;
-    int i;
-
-    /* only filename passed */
-    if (firmware[0] != '/')
-    {
-        /* First check in BOOTDIR */
-        snprintf(filename, sizeof(filename), BOOTDIR "/%s",firmware);
-
-        fd = open(filename, O_RDONLY);
-        if(fd < 0)
-        {
-            /* Check in root dir */
-            snprintf(filename, sizeof(filename),"/%s",firmware);
-            fd = open(filename, O_RDONLY);
+    int f_offset;
+    char add_path[MAX_PATH];
+    /* Check in root of volume for rockbox_main.<playername> redirect */
+    snprintf(add_path, sizeof(add_path), "/<%d>/"BOOT_REDIR, volume);
+    fd = open(add_path, O_RDONLY);
+    if (fd < 0)
+        return EFILE_NOT_FOUND;
+
+    /*clear add_path for re-use*/
+    memset(add_path, 0, sizeof(add_path));
+    f_offset = read(fd, add_path,sizeof(add_path));
+    close(fd);
 
-            if (fd < 0)
-                return EFILE_NOT_FOUND;
-        }
-    }
-    else
+    for(int i = f_offset - 1;i > 0; i--)
     {
-        /* full path passed */
-        fd = open(firmware, O_RDONLY);
-        if (fd < 0)
-            return EFILE_NOT_FOUND;
+        /* strip control chars < SPACE or all if path doesn't start with '/' */
+        if (add_path[i] < 0x20 || add_path[0] != '/')
+           add_path[i] = '\0';
     }
+    /* if '/add_path' is specified in rockbox_main.<playername>
+       path is /<vol#>/add_path/rootdir/firmwarename
+       if add_path is empty or '/' is missing from beginning
+       path is /<vol#>/rootdir/firmwarename
+    */
+    return snprintf(buf, buffer_size, "/<%d>%s/%s/%s", volume, add_path,
+                                                        rootdir, firmware);
+}
+#endif /* HAVE_MULTIBOOT */
+
+/* loads a firmware file from supplied filename
+ * file opened, checks firmware size and checksum
+ * if no error, firmware loaded to supplied buffer
+ * file closed
+ * Returns size of loaded image on success
+ * On error returns Negative value deciphered by means
+ * of strerror() function
+ */
+static int load_firmware_filename(unsigned char* buf,
+                                  const char* filename,
+                                  int buffer_size)
+{
+    int len;
+    unsigned long chksum, sum;
+    int i;
+    int ret;
+    int fd = open(filename, O_RDONLY);
+
+    if (fd < 0)
+        return EFILE_NOT_FOUND;
 
     len = filesize(fd) - 8;
 
@@ -124,18 +147,16 @@ int load_firmware(unsigned char* buf, const char* firmware, int buffer_size)
 
     lseek(fd, FIRMWARE_OFFSET_FILE_CRC, SEEK_SET);
 
-    rc = read(fd, &chksum, 4);
-    chksum = betoh32(chksum); /* Rockbox checksums are big-endian */
-    if(rc < 4)
+    if (read(fd, &chksum, 4) < 4)
     {
         ret = EREAD_CHKSUM_FAILED;
         goto end;
     }
+    chksum = betoh32(chksum); /* Rockbox checksums are big-endian */
 
     lseek(fd, FIRMWARE_OFFSET_FILE_DATA, SEEK_SET);
 
-    rc = read(fd, buf, len);
-    if(rc < len)
+    if (read(fd, buf, len) < len)
     {
         ret = EREAD_IMAGE_FAILED;
         goto end;
@@ -148,19 +169,72 @@ int load_firmware(unsigned char* buf, const char* firmware, int buffer_size)
         sum += buf[i];
     }
 
-    if(sum != chksum)
+    if (sum != chksum)
     {
         ret = EBAD_CHKSUM;
         goto end;
     }
-#ifdef HAVE_BOOTDATA
-    /* 0 is the default boot volume */
-    write_bootdata(buf, ret, 0);
-#endif
     ret = len;
 
-
 end:
     close(fd);
     return ret;
 }
+
+/* Load firmware image in a format created by add method of tools/scramble
+ * on success we return size loaded image
+ * on error we return negative value which can be deciphered by means
+ * of strerror() function
+ */
+int load_firmware(unsigned char* buf, const char* firmware, int buffer_size)
+{
+
+    int ret = EFILE_NOT_FOUND;
+    char filename[MAX_PATH+2];
+    /* only filename passed */
+    if (firmware[0] != '/')
+    {
+
+#ifdef HAVE_MULTIBOOT /* defined by config.h */
+        /* checks <volumes> highest index to lowest for redirect file
+         * 0 is the default boot volume, it is not checked here
+         * if found <volume>/rockbox_main.<playername> and firmware
+         * has a bootdata region this firmware will be loaded */
+        for (unsigned int i = NUM_VOLUMES - 1; i > 0 && ret < 0; i--)
+        {
+            if (get_redirect_dir(filename, sizeof(filename), i,
+                                 BOOTDIR, firmware) > 0)
+            {
+                ret = load_firmware_filename(buf, filename, buffer_size);
+            /* if firmware has no boot_data don't load from external drive */
+                if (write_bootdata(buf, ret, i) <= 0)
+                    ret = EKEY_NOT_FOUND;
+            }
+            /* if ret is valid breaks from loop to continue loading */
+        }
+#endif
+
+        if (ret < 0) /* Check default volume, no valid firmware file loaded yet */
+        {
+            /* First check in BOOTDIR */
+            snprintf(filename, sizeof(filename), BOOTDIR "/%s",firmware);
+
+            ret = load_firmware_filename(buf, filename, buffer_size);
+
+            if (ret < 0)
+            {
+                /* Check in root dir */
+                snprintf(filename, sizeof(filename),"/%s",firmware);
+                ret = load_firmware_filename(buf, filename, buffer_size);
+            }
+#ifdef HAVE_BOOTDATA
+                /* 0 is the default boot volume */
+                write_bootdata(buf, ret, 0);
+#endif
+        }
+    }
+    else /* full path passed ROLO etc.*/
+        ret = load_firmware_filename(buf, firmware, buffer_size);
+
+    return ret;
+}
diff --git a/firmware/export/config.h b/firmware/export/config.h
index 51e0f7a17b..475bd573d4 100644
--- a/firmware/export/config.h
+++ b/firmware/export/config.h
@@ -859,6 +859,11 @@ Lyre prototype 1 */
 #error HAVE_MULTIDRIVE needs to have an explicit NUM_DRIVES
 #endif
 
+/* note to remove multi-partition booting this could be changed to MULTIDRIVE */
+#if defined(HAVE_BOOTDATA) && defined(BOOT_REDIR) && defined(HAVE_MULTIVOLUME)
+#define HAVE_MULTIBOOT
+#endif
+
 #ifndef NUM_DRIVES
 #define NUM_DRIVES 1
 #endif
diff --git a/firmware/export/config/sansaclipplus.h b/firmware/export/config/sansaclipplus.h
index cf2b1136a3..addf7d86c0 100644
--- a/firmware/export/config/sansaclipplus.h
+++ b/firmware/export/config/sansaclipplus.h
@@ -9,6 +9,8 @@
 #define FIRMWARE_OFFSET_FILE_CRC 0
 /* Define if boot data from bootloader has been enabled for the target */
 #define HAVE_BOOTDATA
+/* define boot redirect file name allows booting from external drives */
+#define BOOT_REDIR "rockbox_main.clip+"
 
 #define HAVE_MULTIDRIVE
 #define NUM_DRIVES 2
diff --git a/firmware/export/config/sansaclipzip.h b/firmware/export/config/sansaclipzip.h
index 9f1ff1f206..fc9f558eef 100644
--- a/firmware/export/config/sansaclipzip.h
+++ b/firmware/export/config/sansaclipzip.h
@@ -9,6 +9,8 @@
 #define FIRMWARE_OFFSET_FILE_CRC 0
 /* Define if boot data from bootloader has been enabled for the target */
 #define HAVE_BOOTDATA
+/* define boot redirect file name allows booting from external drives */
+#define BOOT_REDIR "rockbox_main.clipzip"
 
 #define HAVE_MULTIDRIVE
 #define NUM_DRIVES 2
diff --git a/firmware/export/config/sansafuze.h b/firmware/export/config/sansafuze.h
index d674d1f88a..fae3463d75 100644
--- a/firmware/export/config/sansafuze.h
+++ b/firmware/export/config/sansafuze.h
@@ -8,6 +8,9 @@
 /* Define if boot data from bootloader has been enabled for the target */
 #define HAVE_BOOTDATA
 
+/* define boot redirect file name allows booting from external drives */
+#define BOOT_REDIR "rockbox_main.fuze"
+
 #define HW_SAMPR_CAPS       SAMPR_CAP_ALL
 
 /* define this if you have recording possibility */
diff --git a/firmware/export/config/sansafuzeplus.h b/firmware/export/config/sansafuzeplus.h
index af5235a6c3..2a57619b06 100644
--- a/firmware/export/config/sansafuzeplus.h
+++ b/firmware/export/config/sansafuzeplus.h
@@ -10,6 +10,8 @@
 #define MODEL_NAME   "Sandisk Sansa Fuze+"
 /* Define if boot data from bootloader has been enabled for the target */
 #define HAVE_BOOTDATA
+/* define boot redirect file name allows booting from external drives */
+#define BOOT_REDIR "rockbox_main.fuze+"
 
 #define HW_SAMPR_CAPS       SAMPR_CAP_ALL
 
diff --git a/firmware/export/config/sansafuzev2.h b/firmware/export/config/sansafuzev2.h
index a4d90160bd..b85e0747a3 100644
--- a/firmware/export/config/sansafuzev2.h
+++ b/firmware/export/config/sansafuzev2.h
@@ -8,6 +8,9 @@
 /* Define if boot data from bootloader has been enabled for the target */
 #define HAVE_BOOTDATA
 
+/* define boot redirect file name allows booting from external drives */
+#define BOOT_REDIR "rockbox_main.fuze2"
+
 #define HW_SAMPR_CAPS       SAMPR_CAP_ALL
 
 /* define this if you have recording possibility */
diff --git a/firmware/include/rb-loader.h b/firmware/include/rb-loader.h
index 86c5026af9..71b6e038aa 100644
--- a/firmware/include/rb-loader.h
+++ b/firmware/include/rb-loader.h
@@ -19,3 +19,20 @@
  ****************************************************************************/
 
 int load_firmware(unsigned char* buf, const char* firmware, int buffer_size);
+
+#ifdef HAVE_MULTIBOOT /* defined by config.h */
+/* Check in root of this <volume> for rockbox_main.<playername>
+ * if this file empty or there is a single slash '/'
+ * buf = '<volume#>/<rootdir>/<firmware(name)>\0'
+ * If instead '/<*DIRECTORY*>' is supplied
+ * addpath will be set to this DIRECTORY buf =
+ * '/<volume#>/addpath/<rootdir>/<firmware(name)>\0'
+ * On error returns Negative number or 0
+ * On success returns bytes from snprintf
+ * and generated path will be placed in buf
+ * note: if supplied buffer is too small return will be
+ * the number of bytes that would have been written
+ */
+int get_redirect_dir(char* buf, int buffer_size, int volume,
+                     const char* rootdir, const char* firmware);
+#endif