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Revised Section 6.2.4 of UserGuide See Issue #508

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@@ -2117,13 +2117,13 @@ survive re-imaging, you **must** follow these rules:
This section covers techniques to copy partial images onto pre-existing media,
in effect performing a selective slice copy. These techniques currently **only** apply to
hd1k formatted media, which has a convenient 1MB size metric.
hd1k formatted media, which has a partition table entry, and a convenient 1MB size metric.
However adapting to hd512 is possible, but left to the user.
On Linux/MacOS the `dd` command can be used to write data in a controlled manner.
Although Windows does not have a native `dd` command, there are multiple
options for installing it including [MSYS2](https://www.msys2.org/),
[CygWin](https://www.cygwin.com/),
You will need to have access to a Linux/MacOS machine, or have the
Linux tools for Windows installed, including the `dd` command line tool.
For Windows there are multiple options for installing `dd` including
[MSYS2](https://www.msys2.org/), [CygWin](https://www.cygwin.com/),
and [dd for Windows](http://www.chrysocome.net/dd).
**WARNING**: The `dd` command is a low-level utility that writes
@@ -2146,21 +2146,79 @@ From the documentation of `dd` the following options are important.
of the default 512
```
In the following examples we use the above options, noting the `of=` option
is specific to your computer but defines the block device that the target
media is mounted to in the operating system,
and `bs=1MB` defines the block size used in other parameters which is convienient
since it aligns perfectly with slices which are exactly 8MB
and the initial partition table is exactly 1MB.
The best approach is to copy data to the RomWBW partition. To do this, you
must first determine the name that your operating system is using for the
RomWBW disk and partition. An easy way to determine this may be the linux `mount`
command, which lists the currently mounted partitions. From here you can more easily
determine the naming scheme used by your operating system.
Typically disk devices are named something like `/dev/disk9` or `/dev/sdg`, noting above
the `g` is a alphabetic and it could be any letter. This naming is arbitrary
and depend on the operating system, and the specific hardware connecting the device
Partitions are typically named by simply adding a number after the name of the hard disk
device. For example, the first partition could be `/dev/disk9s1`, `/dev/sdg1`, or `/dev/sdgp1`.
In the following examples we use the above `dd` options, noting the `of=` option
is the RomWBW target partition.
** NOTE ** A second approach (Examples 3 and 4) the hard disk is addressed as a raw disk
device and we take explicit steps to calculate the start of the RomWBW
partition. While this work's, it is better to use the partition relative approach
The commands in the examples below are run from the `Binary` folder of RomWBW distribution.
#### Example 1 : Copy the Combo Image without replacing partition table
#### Example 1 : Copy the Games image to an empty slice of our media
In this example we will copy the (hd1k) combo image over our media
without replacing the partition table. In this example we assume the media
has already been formated with the combo image, and we have modified
the partition table, which we do not want to overrite.
In this example we will copy the (hd1k) games image to Slice 6 (free)
of our existing media. In this example we assume the media
has already been formatted with the combo image, which already
contains 6 slices (numbered from 0 to 5)
We are just coping the needed slice to the existing media
as a new slice (number 6) after the existing slices making it the 7th slice.
```
Binary % sudo dd if=hd1k_games.img of=/dev/sdg1 seek=6 bs=8M
Password:
1+0 records in
1+0 records out
8388608 bytes transferred in 1.917296 secs (4375228 bytes/sec)
```
Since bs=8MB the `seek=6` skips the first 6 (8MB slices) slices (in the target image)
and writes the games image to the 7th slice.
#### Example 2 : Copy the entire Combo Image without replacing partition table
In all the following examples we use `bs=1MB` to defines the block size used
in other parameters. This is convenient since the combo image reserves 1MB for
the partition table at the start of the disk.
In this example we will copy the (hd1k) combo image (which includes a partition table)
over our media without replacing the partition table. In this example we assume the media
has already been formatted with the combo image, and we have modified the partition table,
which we do not want to overwrite.
```
Binary % sudo dd if=hd1k_combo.img of=/dev/sdg1 skip=1 bs=1M
Password:
48+0 records in
48+0 records out
50331648 bytes transferred in 11.503776 secs (4745528 bytes/sec)
```
The `skip=1` skips the first 1MB (partition table) in the input file,
effectively stripping out the combo images partition table, before overwriting
the slices in the target partition.
#### Example 3 : Copy the Combo Image without replacing partition table
This example is identical to Example 2 except it writes to the target
disk device itself (`of=/dev/disk9`), not the target partition.
```
Binary % sudo dd if=hd1k_combo.img of=/dev/disk9 skip=1 seek=1 bs=1M
@@ -2174,14 +2232,14 @@ Password:
The `skip=1` skips the first 1MB in the input file, and likewise
`seek=1` skips the first 1MB of the target media file we are writing to,
tus in effect we are skipping the first 1MB, which contains the
thus in effect we are skipping the first 1MB, which contains the
partition table itself.
#### Example 2 : Copy the Games image to an empty slice of our media
#### Example 4 : Copy the Games image to an empty slice of our media
In this example we will copy the (hd1k) games image to Slice 6 (free)
of our existing media. In this example we assume the media
has already been formated with the combo image, which already
has already been formatted with the combo image, which already
contains 6 slices (numbered from 0 to 5)
We are just coping the needed slice to this existing media
as a new slice (number 6) after the existing slices making it the 7th slice.
@@ -2203,27 +2261,6 @@ and 1 is the size of the partition table im megabytes.
Thus we are skipping 6 slices (in the combo image)
and writing to the 7th slice.
#### Example 3 : Copy image using partition
In the previous examples, the hard disk is addressed as a raw disk
device and we took steps to calculate the assumed start of the RomWBW
partition. However, as long as the hd1k format is in use, it is
also possible to just point `dd` directly to the partition itself.
To do this, you must first determine the name that your operating
system is using for the desired partition. Frequently, partitions
are named by simply adding a number after the name of the hard disk
device. For example, if the hard disk is /dev/sdg, the first
partition is frequently /dev/sdg1 or /dev/sdgp1.
Taking advantage of this, it is safer and easier to calculate the
offset of a slice within the partition. It is simply the slice
number \* 8MB. Example 2 above, could now be performed as:
```
Binary % sudo dd if=hd1k_games.img of=/dev/sdg1 seek=48 bs=1M
```
# Operating Systems
One of the primary goals of RomWBW is to expose a set of generic