[lkml]   [2011]   [Apr]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 1/1] Implement /dev/byte (a generic byte source similiar to /dev/zero)
On Mon 2011-04-18 13:37:56, Alexander Holler wrote:
> This device outputs by default 0xff instead 0 which makes more sense
> than 0 to clear e.g. FLASH based devices.

Well, now you should provide example where you mmap /dev/byte, then
write() the flash directly from the mapping.

... hmm, that brings good question: what happens on existing mappings
when the byte is changed?

> To make the device more general usable, the value it outputs is changeable
> on a per file descriptor basis through simple writes to it.
> Values can be decimal (0 - 255), octal (00 - 0377) or hex (0x0 - 0xff).
> For other values (or strings) written to it, the write operation returns an
> error and the subsequent output is undefined.
> # Create a file of size 10GB and filled with 0xaa.
> exec 5<>/dev/byte # Open /dev/byte and assign fd 5 to it
> echo 0xaa >&5 # Instruct the device to output 0xaa

That's seriously strange. /dev/byte should be changeable... by writing
(cesky, pictures)

 \ /
  Last update: 2011-04-20 15:45    [W:0.067 / U:7.228 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site