DR800 ANN: DR800+. Port of some DR1000 features to the DR800

[Iñigo]

Originally Posted by lacol

Iñigo, you mention in the readme of dr800+ that you improved performance at some point by applying optimizations during compilation. Do you know if Irex applied the same optimizations in compiling the original rc3 firmware ?

In other words, would completely recompiling from source the 2.0-RC3 firmware result in a performance increase even when doing no modification to the source, but using the compiler optimizations mentionned in the readme of dr800+ ?

And by the way, how does one apply those optimization ? Is this something that should appear in the makefile ? I can't seem to find any trace of them in any configure.ac or makefile.am file in the source of your dr800+ package.

Those optimizations are passing some flags to the compiler:
"-mcpu=arm1136jf-s -mtune=arm1136jf-s -O3 -funroll-loops"
They generate special code for the ARM CPUs DR ereaders have.

They don't appear in the sources, as I added next lines to my environment-setup initialization script:

export CFLAGS="-mcpu=arm1136jf-s -mtune=arm1136jf-s -O3 -funroll-loops"
export CXXFLAGS="-mcpu=arm1136jf-s -mtune=arm1136jf-s -O3 -funroll-loops"

I'm not sure but I think they were not applied in IREX firmware, as same sources result in different binary size. Maybe Gertjan could add more here.

I think I noted some speed improvement when I compiled some code: ctb, popupmenu, ermetadb... But I'm not sure it will make DR faster. Anyway, not more than 2-3%

Iñigo

[dima_tr]

I still believe -funroll-loops gives an essential speed improvement for sqlite binary. At least this I have observed on its PC version on my i386 Ubuntu - an order of 20-30% faster.

[Iñigo]

Originally Posted by dima_tr

I still believe -funroll-loops gives an essential speed improvement for sqlite binary. At least this I have observed on its PC version on my i386 Ubuntu - an order of 20-30% faster.

I forgot about it...
dima_tr is right, recompiling sql-amalgamation with these flags make the library noticeable faster, but I got some problems with that version and my "icons" program. Not with DR software.

[yuri_b]

You forgot or don't know another aspect of unroll-loop optimizaion:
It encrease code size, the programm going to be bigger, and this is not good for ARM systems: the reason very simple the more code size - the more code must be read from memory into CPU, this CPU has 16KB data/16KB instruction cache -> a small and very fast memory, so most effisient function would be function with loops no bigger then 16KB - cache size, our regular memory: 128MB is a slow memory with slow access thru bus, so big functions will degrade overall perfomance of system.
This is a paradox: faster function are bigger and can be slower then small and not fast one, due to slow bus access to memory.
In my company we don't use unroll loops: because small size of code cache and big price of fast memory.
http://www.arm.com/products/processo...11/arm1136.php

Sincerely
Yura

[jonathan_s]

Having just started using DR800+ I have a few questions/problems. Apologies if these have been answered elsewhere.

1. PDF writing/annotation. I use this a lot and was very disappointed to find that it seems to be broken. Writing seems to work but occasionally disappears and is forgotten if you leave and come back to a page.

1a. I was/am still hopeful that it will become possible to export PDF annotations.

2. I love having the time in the status bar. But it doesn't appear to refresh automatically, and not even when I scroll pages, but only when I enter the 'Start' menu.

Cheers,
Jonathan

[fekhner]

1. use Xournal to open and then annotate pdf (with experimental update option selected)
https://www.mobileread.com/forums/showthread.php?t=87593
1a. export as pdf of annotated files is possible. Furthermore, for pure notes, there are some ocr programs (myscriptnotes for instance) that allow you to convert your notes on your computer if you save them as .irx files

[Iñigo]

Originally Posted by jonathan_s

2. I love having the time in the status bar. But it doesn't appear to refresh automatically, and not even when I scroll pages, but only when I enter the 'Start' menu.

First development versions of this feature updated the clock each minute, but it drained a lot of battery. So we changed the behaviour to update the clock in page turns or whenever there is a screen update (f.e. opening the "start" menu).

Iñigo

[jonathan_s]

Originally Posted by Iñigo

First development versions of this feature updated the clock each minute, but it drained a lot of battery. So we changed the behaviour to update the clock in page turns or whenever there is a screen update (f.e. opening the "start" menu).

That was what I'd guessed and makes perfect sense - though maybe it could be configurable. But I find that the clock doesn't update on page turns, only on the start menu.

[jonathan_s]

Originally Posted by Iñigo

apart from rxvt, take a look at usbnet, as Fehner has already mentioned.

what would be the benefits?

30k+ applications already built, running and maintained by the Debian folk, all while keeping leaving the native firmware untouched. This is the way to run OpenOffice/LibreOffice on (for example) a Nokia N900 and it works really well.

[Iñigo]

Originally Posted by jonathan_s

30k+ applications already built, running and maintained by the Debian folk, all while keeping leaving the native firmware untouched. This is the way to run OpenOffice/LibreOffice on (for example) a Nokia N900 and it works really well.

Sorry, I disagree.
30k already built apps.. that were coded for a proper screen, keyboard and mouse to work.
How will you use libreoffice on the DR? only the menus will take half the screen, and you need 1/3th for the virtual keyboard...

The DR is a special kind of device, so to make an app for the DR is not only matter of rebuilding, you'll need to adapt the menus, the toolbars, the screen refresh handling, the input, etc... if you want to make it really useful for the DR. Recompiling is the easy part.

I don't pretend to be negative, just show that it's not as easy as it could look.
I ported many apps at the beginning, but we need extra work to make it suitable for the DR.

Anyway, show me that I'm wrong, and go for it!

[jonathan_s]

Originally Posted by Iñigo

Anyway, show me that I'm wrong, and go for it!

I'll see how I go.

I would point out that Debian isn't only for full size 'real' computers - different display managers work fine on the much smaller screen on my smartphone and a variety of other devices. That said, unless I can get an external keyboard working it isn't going to be much use for entering information. Also, it's not just for interactive applications but for all the other tools that can be used in scripts of whatever that haven't been ported.

Anyway next step is to face the learning curve of building kernel modules.

And can I ask you one question while I'm here. Where can I find info about reflashing the IREX if I do manage to brick it up?

Cheers!

[Iñigo]

Originally Posted by jonathan_s

And can I ask you one question while I'm here. Where can I find info about reflashing the IREX if I do manage to brick it up?

It's quite easy, the same process used in an upgrade: copy the firmware in the System folder of the SD card and reboot. It will reflash automatically.

IREX people did a very good job here.

Iñigo

[marcins]

Originally Posted by Iñigo

It's quite easy, the same process used in an upgrade: copy the firmware in the System folder of the SD card and reboot. It will reflash automatically.

Unless one manages to damage the bootloader, I suppose.

[rvs]

Having an external keyboard would be great, but I don't think it's possible without some hardware hacking.

[jonathan_s]

Originally Posted by fekhner

1. use Xournal to open and then annotate pdf (with experimental update option selected)
https://www.mobileread.com/forums/showthread.php?t=87593
1a. export as pdf of annotated files is possible. Furthermore, for pure notes, there are some ocr programs (myscriptnotes for instance) that allow you to convert your notes on your computer if you save them as .irx files

Thanks for the help. I'm sorry to be fussy but xournal is too heavy and doesn't give me the same satisfaction as being able to annotate inside the basic FBreader. I like having the same kind of feeling as writing on the newspaper that I am reading. Now I read my newspapers on the DR800 I still want to be able to do Sodoku , crosswords, or just write thoughts onto it. Also it's a step backwards from the previous firmware, so possibly just a small bug that got introduced, since it still almost works(?)

So my questions are - is there any good explanation for why the PDF annotation no longer works? I'm happy to go poking around but would appreciate any prior knowledge that readers of this thread may already have.

Loving the DR800+ as a whole new toy