- entry 2011/05/08

ARM disassembler to come

Anyway, I digress. The big strange problem is that there doesn't seem to be an efficient, capable GUI disassembler. There is, of course, the command line objdump for Linux (maybe a Windows one?) and there are non-free GUI options, namely:

• IDAPro - this is the be-all of disassemblers. However I don't justify hundreds of dollars for a disassembler that can deal with dozens of processor families, many of which I have never used, and probably never will...
  There's a free version, but it doesn't do ARM.
• BDAsm - looks, at a glance, to be fairly capable. That is, until you realise the link addresses are all messed up (failure to sign extend?). I didn't look to see what else is wrong, because that's a pretty big problem!

So, then, using the venerable !Zap as a template, I decided to roll my own. ☺

It will support the ARM v5 architecture, with support for the ARM926. This is because it is being written specifically to allow poking around in the Neuros OSD's code. In addition, it will be designed with support for RISC OS and the ARM v2/v3 (ARM 3, ARM710).

That isn't to mean there aren't problems. Not big ones, it's just that as of the newer generation of ARM processors, the instruction set gets a bit fiddly. For example, once you have decoded a data processing instruction (SUB, RSB, etc) then you have to further decode to see if it really is that, or if it is something like UMULLS.
By digging into the ARM instruction set at a binary level, you start to appreciate that the arrangement of the processor is an interesting blend of simplicity and complexity that produces powerful results. No, that isn't a contradiction, for when you look at the instruction set, there are an astonishing array of options packed into those 28 bit words. 28 bits? Yup, that's because the upper four bits are condition codes. Couple that with the S bit (whether or not to affect the status register), you have the ability to perform arithmetic instructions without altering the status flags, and the ability to conditionally execute instructions based upon the state of the status flags.

To understand this in action, Wikipedia gives the following example. Consider some code in C:

    while(i != j) {
       if (i > j)
           i -= j;
       else
           j -= i;
    }

Prepare for the ARM version:

 loop   CMP    Ri, Rj       ; set condition "NE" if (i != j),
                            ;               "GT" if (i > j),
                            ;            or "LT" if (i < j)
        SUBGT  Ri, Ri, Rj   ; if "GT" (greater than), i = i-j;
        SUBLT  Rj, Rj, Ri   ; if "LT" (less than), j = j-i;
        BNE    loop         ; if "NE" (not equal), then loop

Anyway, I've only just started, don't expect to progress too quickly, however I can show you the state of play. Here is a screenshot of Zap in action:

And here, for your enjoyment, is the state of play of ArmitageIII:

There is a disparity in the red values of the second column. I'm not entirely certain how Zap denotes control codes. What I have done is run them from 0 to 9, then A upwards through the alphabet, this codes 0-15 will have a hex value to match (13 = D, just like 0x0D).

It is, I should point out, the first version, despite carrying the number 3. If the title makes no sense to you other than figuring out it has "arm" in it, please look at this Wiki article that describes Armitage III.
Then you'll get the idea...

"Dogshit everywhere"?

Speaking of which...

Where's Maddie?

She's been quite nicely cuted up for this age progression photo. Personally, if you ask me, I would be inclined to suggest that you dredge the sea near the hotel she was staying to see what the fishes left behind. There is always the want to hope that the girl is alive, though I wonder if the legend "Missing & exploited" isn't something of a stretch.
The Portuguese detective in charge of the investigation (Goncalo Amaral) thinks that the girl died in the apartment in Portugal. He wrote a book about it, but this was subject to a libel prosecution (ongoing?) and a gagging order. His next book was called, oddly enough, "The English Gag".

I am not sure exactly how the McCanns plan to sue for libel. They can, of course, claim that Maddie was taken, but what they can't do is prove that she didn't die in their room that night.

Is this a useless detective dumping blame on the parents to make an easy resolution to the case, or is this an abuse of power by those responsible to prevent their involvement being questioned? I have a feeling this one will be like "who shot Kennedy?".

The fun thing about the Internet is that they have taken time and money to prevent the book being published. Oh well, that won't stop it. You can read it here, make up your own mind.

Before you do - I should point out that as of 31st March 2008, the released accounts of the Madeleine fund was as follows [source figures, but this is laid out nicer]:

So... their daughter is missing or dead because the parents were off having a meal rather than looking after their children, their fund sits to the sum of a million, with rather more expenditure on publicity and lawyers than actually looking for the child, and the only prosecution proceedings to have come of this so far is against the detective. Doesn't that all seem a little... peculiar?

Authentic Japanese rice

I don't plan to cook this until I get a rice cooker to do it more justice than spinning around in the microwave.

Some you win, some you lose

However... to make matters worse. I will be down three days pay next month for the days I was off. It could have been worse, I had a day docked this month, but nicely I was credited for Easter Monday even though I was 'sick' on that day. But next month I can look forward to being around €180-€200 down. This is why I've told mom that I want to have a few months off of paying for the car loan - she never really 'took' to the Saxo so has plans of trading it in for something else. But I always feel like I'm neither coming nor going. My Satsuki order and a book from Amazon are the only perks I get from 161 hours of working. So in a way it will be a little nicer to make that extra pay, even though I'll be more of a zombie than normal. And, come November when the car is paid for, it will be nice to put the amount of the loan into savings, so I actually have a little something to fall back on should I be ill again. Well, it's my first absence in two and a half years, not bad...

The rules are as follows - if you are ill for one to three days, you get nothing. From the fourth day, the CPAM (social service) will provide an amount of pay, but apparently they take forever to get around to doing anything. After around a week, both the CPAM and the company will provide money so you will have some sort of income. This goes up to three months. The rule is, obviously, if you're going to be ill, be very ill, for a long time.
I understand it is part and parcel of how to stop people taking sickies, but it sucks when you are genuinely ill...

Let it rain

Vide greniers

I spent a couple of euros and purchased a Casio labelling machine, a KL-2000. I figured, what the heck, it might be fun to play with.

It became obvious very quickly that the internal NiCad battery pack had given up the ghost and leaked all over the place. Trusty screwdriver in hand, and a recycling bag on the table to catch anything nasty, I took the machine apart and wiped all of the slime off. The power pack provided was only capable of a mere (and rather lame) 100mA, it would appear that the device is only intended to charge the battery pack. Not only that, but tests with other power packs hint to the labeller actually being unable to run from a mains power pack. This wasn't a problem, I took apart the old battery and removed the wires and fuse. The fuse was kept, and the wires were shoved into the plug from a power brick (you can just see this at the bottom of the picture, under the 'M' key). Then, it worked.
It seems a pretty respectable bit of kit, although numerous functions are a little obscure (power-up with 'B' held to enter "barcode printer mode") or over-complicated. But for what it is, it is fairly powerful and flexible.
You can see a small example stuck to the front panel under the Casio KL-2000 branding. That is two-line printing on a 9mm wide tape. The tape contained within the unit is silver on transparent, perhaps the least useful combination I can think of!
I have discovered I can get labels from Amazon, but at a cost of around €23 a cartridge... it'll be a while before I get to buying that!

I plan to revamp my room. Throw away a lot of old crap, and give myself some workspace. I am thoroughly annoyed with meddling with stuff on a book on my bed. It's the quickest way of losing screws you can imagine. I want a table. I don't plan to entertain much working with the bricked Neuros OSD until I have a table, something to open it out on. I also want shelves because, I swear, I must have several dozen jeweller's screwdrivers around here. But can I lay my hands on a mid-sized cross-head? Can I heck.
So this thing will come in useful as instead of trying to remember what device plugs into which port of the router, I can print a little label to stick to the front. Also, I can put labels on equipment to specify its hostname and IP address. That sort of thing.

Me? Organised? Wow. [no, I wouldn't believe it either!]

Now, what kind of geek would I be if I didn't include this:

Just below the processor, on the lower right, is a 32KiB "pseudo static RAM", with a 120ns access time. The "pseudo" part means it is essentially a dynamic RAM with built-in refresh circuitry so it can refresh itself rather than requiring the processor to refresh. This allows the processor the ability to suspend to save power, without worrying about losing the contents of the memory.

To the left of the processor is a 128KiB mask ROM, which will hold the system firmware.

It would appear that the big chip is an ASIC, so its function will be custom to the device. Looking at the circuit board, it would be - at a guess - an interface between the processor and the I/O and display (which is a separate board - the white connections leading to this).

The final thing is the chunky chip on the left. It is a high current Darlington transistor array. Leading to the printer board, this will control the data matrix for the print head, and also the motor.

The other board contains an LCD signal row driver, and two LCD signal column drivers. It is not immediately obvious what handles the keyboard matrix. I don't plan to take the thing apart more to find out...

The interesting thing is that this device appeared to be reliable and bug free. I guess the flexibility of FlashROM is not always the blessing it is thought to be, for while bugs are inevitable, it seems to me nowadays that more and more "problems" are considered acceptable as a company can just issue a firmware update. Or not, as the case frequently is. But back in these days, firmware was committed to a mask-programmed ROM that was soldered to the board. It simply had to be right, or at least the bugs being minor things.

There wasn't anything else of much interest at the vide grenier, though it was interesting to note that some people wore light clothes and fairly open shoes, while others dressed more appropriately for the weather - with one slightly overdressing in waders and a plastic poncho. Those dressed in a more summery manner got a little soggy. Speaking of which...

Can you say continuity?

Anyway... About five minutes in we see the lead character waiting at a bus stop.
It is raining. A lot.

Oh, BBC. Seriously? ☺

Animé

But there is one I will carry on with, and I like it so much I'll be interested in a release date of region 2 DVDs...

Steins;Gate (1-5)

Based loosely around a crazy-scientist-meets-cute-a-smart-chick with a lot of the John Titor legend tossed in, this is a slow-burn series in which takes its time, and throws out annoyingly tantalising hints.

The story opens with a lengthy disconnect. We see the mad scientist Okarin wandering around a press conference on time travel. He wears a lab coat. He always wears a lab coat. He is also something of a paranoid conspiracy nut, convinced they are out to get him, whoever "they" might be. Following him around like a faithful puppy is a girl called Mayuri who is kinda cute but lacking in brains. The name Okarin was given to him by Mayuri, as a contraction of his real name Rintarô Okabe. This seems to be a Japanese thing - "Nodame (Cantabile)" is from Megumi Noda. Okarin, by the way, gives his name as "Kyôma Hôôin".
The press conference seems to consist of little more than a rehash of the John Titor story. Leaving the report after pointing this out, Okarin bumps into a girl called Kurisu. Okarin recognises the girl from something she wrote, but while she seems to think she spoke to him only a little while ago, he seems confused. It didn't happen.
Mere moments later, during a scene involving Mayuri and a toy, we hear a scream. Okarin rushes off, to find Kirusu dead in a pool of blood.
Okarin panics, as you would, then reaches for his phone. And for just a moment is utterly alone in a street in a deserted world. A blink and everybody is there, but, wait, there is a satellite embedded in the building he'd just been standing in. Not wreckage, not pieces that survived re-entry, but an entire satellite, just... there...

Back at base, we meet the other person in the "Future Gadget Lab", a hacker-supreme called "Daru" who has a rather dirty mind. However the essence of the Future Gadget Lab is that it isn't really anything serious. The hacker has nothing better to do and the mad scientist is delusional to the point of possibly being unable to function in society.

On to episode two, which starts with Okarin prodding and groping a somewhat perturbed Kurisu, who is quite definitely not dead. Did this happen, or is it a hint as to the scale of Okarin's delusions?
Okarin attends a lecture on time travel, and it turns out to be held by Kurisu, who explains mathematically why time travel just isn't going to happen. We see that she's a little shy but very bright, although she took a sort of delight in trouncing Okarin's suggestions that time travel could be possible.
Back at base, Okarin hits the web to try to find out what happened previously. He comes up empty, but does run into a character claiming to be John Titor. He wants to slam this obvious imposter off the web, but strangely he can't find any references to John, and the books he had have just vanished. Later, when out, he is taking pictures on his phone (why?) when one of them is a girl who objects. She seems... confused. Borderline deranged, but not like Okarin, more in the way of needing a hug and a good cry. She is looking for an IBM 5100 computer.

For those wondering about "John Titor", he was an online persona in around 2000-2001 who claimed to be a time traveller from 2036. It's kinda cool to see this story picked up and placed into an animé. For those who don't already know about this, and his so-called predictions, read the Wiki article.

In episode three, the "Future Gadget Lab crew are playing with their microwave. It makes stuff turn into an icky green jelly. Something goes wrong, involving a mobile phone, and the banana vanishes from the microwave...
...only to turn up completely reattached to the clump of bananas it came from, only green and icky. It just so happens that this entire scene was witnessed by Kurisu. A lot of talk, going all around until Kurisu reins in the boys and asks exactly what happened to the banana? There is more experimentation, which involves a message sent on the mobile phone travelling into the past when it is connected to the microwave. This leads to only one possibility that makes any sort of sense - time travel. As soon as the realisation of this sinks in, Kurisu turns around and runs.
We meet another girl, "Suzuha", a CRT enthusiast who is working part time in the TV repair shop downstairs.
Okarin turns his focus back to John Titor, and here we see a lot of conspiracy guff about CERN (amusingly fansubbed as "SERN"!), how they have the monopoly on time travel, how it's all about creating some sort of miniature black hole to make time travel real, how the Large Hadron Colider is for this purpose, how... et cetera et cetera. All of this leads Okarin to ask Daru to hack into CERN. Which in true sci-fi fashion is a mildly trivial event. Only, wait, some of the stuff supports Titor's story. What happens if you dump a delusional conspiracy theorist into the middle of an epic conspiracy?

Swiftly on to episode four, there are references to a dead person in the CERN messages, plus a file that resists decoding or decyphering - something that annoys the hell out of Daru. It will require... doo-da-doooo!... an IBM 5100 computer! The hunt is on, and along the way Okarin bumps into Kurisu who is in complete denial over what happened in the Future Gadget Lab, yet she is somehow fascinated by everything that is going on, albeit slightly annoyed that Okarin insists on calling her Christina. Then, yet another character is introduced in a lengthy way. A maid in a café. She is called "Feyris" and she appears to be about as delusional as Okarin, but he has to be nice and play a game with her in order to extract some information that might help him locate this computer he is after. He plays the game with some style, instantly losing and then pointing out that the request was to play, not to win. Begrudgingly, Feyris tells him to visit a shrine. A shrine that has just such a computer. And a reasonably pretty girl... who is actually a boy.

Up to date, episode five. The barrow is broken, so Kurisu and Okarin lug the heavy computer back to base. However just before, the repair girl Suzuha glares at Kurisu and adopts a stance with something like a golf club that suggests she's all but ready to beat the crap out of Kurisu. This is quickly defused by the owner of the shop telling her to get back to work, but... what? What was that all about?
Kurisu hears Mayuri saying she is Okarin's hostage and is in the process of phoning the police when Mayuri admits she made herself his hostage. Kurisu is floored - is anybody in this place even borderline normal?
As they live in Akihabara, Okarin pops out to get some spare parts so Daru can get the 5100 up and running in a matter of hours. Along the way, Suzuha warns Okarin not to trust Kurisu, and freaks out as a helicopter passes overheard.
The IBM 5100 effortlessly translates the super-secret text into something readable (my God, the 5100 didn't even have a real processor inside!), so the group start to piece together the CERN time travel story, where people have turned up in various locations and times, all of them a kind of icky green jelly. Sound familiar?
There is a lovely scene, following a board game, where Kurisu tells Okabe (his real name) that he isn't good at taking a strategic view. He only considers his own strategy and doesn't consider that of the opponent, and thus doesn't realise when something is a trap. Okarin explodes, not in fury about being criticised, but about Kurisu's neglect of calling him hoooooooin, saying "How many times must I tell you, Christina?" (yeah, like he gets her name right!). She starts to cry, and denies it saying "I definitely wasn't terrified by a guy screaming in my face, so I definitely didn't start crying from relief afterwards! That's not what happened!" So Okarin asks Daru why she is crying, and he said "She just told you, dumb-ass".

With another 19 episodes to go, this series can afford to take its leisurely pace, and be tantalisingly annoying about it. This is one episode I wish I stumbled on at some later date so I could get all the episodes, wipe an entire day off my calendar, and just watch it from beginning to end. Having to wait each week is surely a form of cruelty!

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Jess, 12th May 2011, 05:09

The mother everybody loves to hate will be on desert island discs if you listen to radio four.    Do not forget as well that they didn't spend time and money getting the book gagged; it was yet more publicity for them and silencing their critic and it was donation money they used to do it. Ding-a!

tim, 30th May 2011, 19:36

I have seen numbered jigsaw pieces used in a management training context, where the thing could be quickly assembled number-side up and then flipped to show the solution. The clue is that you give a group two trays to aid with the flipping. The puzzle can be in the way the thing is numbered.

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