[minix3] what is "DEV_IMGRD"

[bootbhai]

#define DEV_IMGRD 0x0106

can we set "DEV_IMGRD" to another value??

--
You received this message because you are subscribed to the Google Groups "minix3" group.
To post to this group, send email to min...@googlegroups.com.
To unsubscribe from this group, send email to minix3+un...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/minix3?hl=en.

[AntoineLeca]

On May 1st, 17:40, bootbhai asked
> what is "DEV_IMGRD":

The symbolic name to which is known to the file system server the
RamDisk embedded into the boot IMaGe, using the protocol invented for
MINIX3 in 2005 (previously was used /dev/ram that is 1,0).

> #define DEV_IMGRD   0x0106
>
> can we set "DEV_IMGRD" to another value??

Sure, but what is the point?

Anyway, 0x0106 should be split into two octets; the first (the major)
refers to the memory devices (and hence the memory driver); I do not
believe you want to change that, particularly not at boot time since
it would mean loading and initializing another driver as part of the
image.
About the second (the minor), here you have more freedom in the way it
could be anything else; of course, it could not be something which is
already used with another purpose, in any other place of MINIX (any
version) or any ported or contributed software: for example, a likely
value for designing an initrd (as known in Linux) could be 1,7 or
0x107; if you make 1,7 designing an embeeded ramdisk instead, that
initrd stuff will become brocken.
Also, if you change DEV_IMGRD, you should change it at any place the
*value* is used, which could be much more than just that manifest
constant...

So I repeat: what is the point to change a magic cookie like
DEV_IMGRD?


Antoine