Rockbox

Tasklist

FS#1604 - Faster rolo_load

Attached to Project: Rockbox
Opened by Magnus Holmgren (learman) - Saturday, 09 August 2003, 13:40 GMT
Last edited by Jörg Hohensohn (hohensoh) - Sunday, 12 October 2003, 16:42 GMT
Task Type Patches
Category
Status Closed
Assigned To Jörg Hohensohn (hohensoh)
Operating System
Severity Low
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 0%
Votes 0
Private No

Details

This patch speeds up the rolo_load function, by
implementing the descrambling part in assembler (and in
a more efficient form). Also, the descrambling
calculates the checksum as it goes, saving a little
more time. Descrambling time is reduced from about 1.6
to 0.3 seconds (on a player, with a .mod file on
122,534 bytes).

As the patch also moves the "critical" part of
rolo_load to the internal RAM (this, including
descrambling and checksumming, needs 88 bytes), the
.topcode section is removed.

descramble.S is attached separately, because I don't
know how to make cvs diff include it in the patch... :/
This task depends upon

Closed by  Jörg Hohensohn (hohensoh)
Sunday, 12 October 2003, 16:42 GMT
Reason for closing:  Accepted
Comment by Magnus Holmgren (learman) - Saturday, 09 August 2003, 13:42 GMT

Adding descramble.S as well.
Comment by Magnus Holmgren (learman) - Sunday, 17 August 2003, 07:46 GMT

Did some more tweaking on descramble.S, so that it is ~30%
faster. :)

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