Hi!
On 13:29 Wed 18 Feb , Troy, Willis wrote:
> Howdy,
>
> I am fairly new to device drivers and this list, but I'm sure someone in here
> can help me.
>
> First, some background. I am working on device drivers for a FPGA that is
> currently running kernel 2.6.28, because it is an FPGA I can add custom
> hardware. The custom hardware I currently have is very simple- just a
> multiplier- for a proof of concept. Currently I have a char device driver
> written for it that will take in ascii and multiply its ascii value by
> another ascii value. Eg. 0x0=char(0)*char(0)=48*48. This isn't really what
> I want, I want a device driver that can read in two 32 bit numbers and return
> a 32 bit number.
>
> So, can I write integers/longs to a character device driver? Is there a
> better way to do this?
1) Convert the number to little/big endian
2) cast the int to a "char *" using the addressof operator+typecast
3) call write(fd, "your casted int", 4)
When reading the result:
1) declare an int
2) cast this int to a char *
3) call read
4) convert from little/big endian to mashine byte order
DO NOT DECLARE "char[4]" AND CAST THIS TO AN "int *". THIS WILL FUNCTION ON
SOME MACHINES, BUT NOT ALL.
-Michi
--
programing a layer 3+4 network protocol for mesh networks
see http://michaelblizek.twilightparadox.com
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