Date: Tue, 11 Dec 2001 19:44:13 +0100 From: Poul-Henning Kamp <phk@critter.freebsd.dk> To: "Andrew R. Reiter" <arr@FreeBSD.org> Cc: hackers@FreeBSD.org Subject: Re: Junior Kernel hacker task: Floppy driver mode handling. Message-ID: <34174.1008096253@critter.freebsd.dk> In-Reply-To: Your message of "Tue, 11 Dec 2001 12:40:53 EST." <Pine.NEB.3.96L.1011211124044.27768B-100000@fledge.watson.org>
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In message <Pine.NEB.3.96L.1011211124044.27768B-100000@fledge.watson.org>, "And
rew R. Reiter" writes:
>
>Someone already doing this? If not, I'm down.
You won, you're the first one in my inbox :-)
Ready ?
Steady ?
Start!
:-)
>
>On Tue, 11 Dec 2001, Poul-Henning Kamp wrote:
>
>:
>:There exists a patch for adding a mode to our floppy driver to
>:add DEC RX50 media handling.
>:
>:The crucial part of this is the addition of this line:
>: { 10,2,0xFF,0x10,80, 800,1,FDC_300KBPS,1,0x2E,1 }, /* 400K DEC RX50 */
>:
>:But if one examines the fd.c driver, one cannot help but notice that the
>:handling of densities is a bit convoluted, to put it mildly.
>:
>:I'm looking for a volounteer to do this, it is a quite simple job and
>:I am quite sure that practically everybody has the hardware they need to
>:do this :-)
>:
>:Cleaning it up consists of the following steps:
>:
>:1. Define a new set of (bitmap) macros to distinguish the drive type:
>: #define FD_3S 0x0001 /* 3.5" single density */
>: #define FD_5S 0x0002 /* 5.25" single density */
>: ...
>: And use these instead of the FD_1200 and similar in
>: struct fd_data->type.
>:
>:2. Augment the struct fd_type with two new fields:
>: int minor; /* minor device encoding */
>: int drives; /* bitmap of compatible drives (FD_[35][SD]) */
>: And fill these fields out in the fd_types[NUMTYPES] array.
>: Add a termination entry at the end of the table so the
>: NUMTYPES, NUMDENS, and FD_%d[5_25] #defines can be eliminated.
>:
>:3. Change the _clone code to use the new "minor" field instead of
>: the private table it uses now. (Eliminate and avoid any
>: use of NUMTYPES, NUMDENS and FD_%d[5_25]).
>:
>:4. Change the code in Fdopen to examine the "drives" field in the
>: fd_types[] array instead of the hardcoded switch. (Eliminate
>: and avoid any use of NUMTYPES, NUMDENS and and FD_%d[5_25]);
>:
>:5. Remove any other use of NUMTYPES, NUMDENS and FD_%d[5_25]
>:
>:6. Add the "rx50" entry from above to the table to show how simple
>: that is now.
>:
>:7. Make it possible to define a new mode from userland with an ioctl.
>: (hint: instead of the index, put a pointer to the struct fd_type into
>: the fd_data structure.)
>:
>:Preferably, send one patch per step rather than one huge patch since that
>:will make reviewing easier.
>:
>:First volounteer to send me email gets the assignment.
>:
>:--
>:Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
>:phk@FreeBSD.ORG | TCP/IP since RFC 956
>:FreeBSD committer | BSD since 4.3-tahoe
>:Never attribute to malice what can adequately be explained by incompetence.
>:
>:To Unsubscribe: send mail to majordomo@FreeBSD.org
>:with "unsubscribe freebsd-hackers" in the body of the message
>:
>
>--
>Andrew R. Reiter
>arr@watson.org
>arr@FreeBSD.org
>
>
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message
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