Changes between Version 4 and Version 5 of linux/blockdev

Timestamp:

05/03/2018 05:44:00 PM (7 years ago)

Author:

Ryan Erbstoesser

Comment:

clarify first imaging section, clean up

linux/blockdev

@@ -3 +3 @@
 = Linux Block Storage Devices =
 
-== Imaging a Block device ==
-To place a root filesystem on a removable block storage device (mSATA disk, microSD card, USB Mass Storage device) you need to to the following:
+== Imaging a Block Device (microSD) on a Linux PC ==
+
+These are the instructions to flash something like Ubuntu on a microSD.
+
+The overall theory is that to place a root filesystem on a removable block storage device (mSATA disk, microSD card, USB Mass Storage device) you need to to the following:
  1. Partition the device
  2. Format the partition(s)
@@ -14 +17 @@
  * Can be re-sized even if mounted (via {{{resize2fs}}})
 
-The following commands will perform the above steps on a Linux development host. For convenience we set an env variable to represent the block device - take care to set this properly so as not to format a partition vital to your host (such as its rootfs)
-
-1. Determine device:
+The following commands will perform the above steps on a Linux development host PC/Laptop. For convenience we set an env variable to represent the block device - take care to set this properly so as not to format a partition vital to your host (such as its rootfs)
+
+
+1. Insert the device (microSD) into the Linux PC (a USB to microSD adapter may be needed).
+
+Use the ls command to verify that your microSD was detected by your Linux PC. Example below:
+{{{
+gw@cpu-660:~$ ls /dev/sd*
+/dev/sda  /dev/sda1  /dev/sda2  /dev/sda5  /dev/sdb  /dev/sdb1  /dev/sdb2
+}}}
+ * '''Note''' - /dev/sda is usually the main hard disk of the system. DO NOT write to this.
+ * In this case, no other media is connected to the PC, and thus the microSD is /dev/sdb
+ * '''Note''' - If nothing besides /dev/sda comes up, please refer to the [#mmcblk0Imaging mmcblk0 section]
+
+2. Set the DEVICE variable to the proper device, example given is /dev/sdc:
 {{{#!bash
 DEVICE=/dev/sdc
 }}}
 
-2. Partition device:
+3. Partition device:
 {{{#!bash
 printf "2048,,L,,\n" | sudo sfdisk -uS ${DEVICE}
 }}}
- * here we create a single Linux (type 83) partition offset at 1MiB - you can adjust the parameters to create multiple partitions depending on your needs
-
-3. Format the partition as ext4
+ * Here we create a single Linux (type 83) partition offset at 1MiB - you can adjust the parameters to create multiple partitions depending on your needs
+
+4. Format the partition as ext4
 {{{#!bash
 sudo mkfs.ext4 ${DEVICE}1
 }}}
- * Note that if you put this into a script I've found you need to have a second or so of a sleep following the {{{sfdisk}}} to allow the OS to re-scan the partition table before it will realize that the partition exists
-
-3. Mount the partition:
+ * Note that if you put this into a script it has been found you need to have a second or so of a sleep following the {{{sfdisk}}} to allow the OS to re-scan the partition table before it will realize that the partition exists
+
+5. Mount the partition:
 {{{#!bash
 sudo mount ${DEVICE}1 /mnt/disk
 }}}
- * make sure /mnt/disk exists - this is simply a mount-point
-
-4. Un-archive the rootfs tarball:
+ * Make sure /mnt/disk exists - this is simply a mount-point. If it does not exist, use the mkdir command to create it.
+
+6. Un-archive the rootfs tarball to the /mnt/disk location:
 {{{#!bash
 sudo tar -C /mnt/disk -xvf rootfs.tar.bz2
@@ -45 +60 @@
  * If instead you have a rootfs directory created with {{{fakeroot}}} or {{{deboostrap}}} you can copy it with a {{{sudo cp -rupv rootfs/*  /mnt/disk}}}
 
-5. Unmount the partition:
+7. Unmount the partition:
 {{{#!bash
 sudo umount /mnt/disk
 }}}
+
+8. Remove the device from the PC and insert/connect to Gateworks SBC
 
 === mmcblk0 Imaging ===