31 January 2018
You can find plenty of guides to booting a Raspberry Pi from the network, but the one’s I’ve seen make one or two assumptions. One is that the official guide assumes that you’re booting off of another Raspberry Pi, which you use to generate the boot folder. Another is that you’ll be providing DHCP and TFTP on the same server, e.g. using
dnsmasq. This is annoying because you end up running two DHCP servers on the same network, and it has the potential to interfere with the network configuration on the server that’s running it.
So here’s my plan. I’ve already got a Tomato router (running Advanced Tomato), and it’s got
dnsmasq as a DHCP server. So in theory I should be able to direct the Pi to my real server, which I’m going to run tftpd-hpa on. The same server also runs my NFS mounts, so I’ll use it to host the root directory for the Pi as well.
I expected this to be simple, but it turned out to be rather hard. There are a lot of moving pieces, and many of them don’t give you much help when they break. So I’m documenting the process here.
What you need to do this:
- A server to host NFS and TFTP
- A router with a configurable DHCP daemon, e.g.
dnsmasq (Tomato-based routers are great for this.)
- A Raspberry Pi 3 (the first model to support netbooting without an SD card) with a working Raspbian installation on an SD card
- A working NFS setup (not hard to do, but not described here)
- Possibly a lot of patience.
The first, and apparently most difficult part, is just getting a working TFTP server. I installed
tftpd-hpa on Ubuntu 17.10, made sure port
69 was unblocked, did some basic configuration. No luck, even over localhost. After some mucking about, I could tell using
-v -v -v with
tftpd was receiving the request, but it never bothered to respond—-and it didn’t say why. After hours of trying different suggestions online, I managed to get a working configuration with the following:
I’m not sure if the
-p is needed, but honestly I’m too scared to change anything now. Some of these settings are almost designed to cause frustration.
--secure isn’t exactly a security setting, it sets the “default” directory to
TFTP_DIRECTORY and translates all addresses to subdirectories of that one. Yes, that’s right, without
--secure, a request for a relative path won’t work. My
/boot files are owned by
umask=022, and that seems to work fine.
The main thing you need to do for tftp is set the directory to the path you want to use for the Pi’s boot files. Since I have the NFS server and the TFTP server on the same hardware, I can conveniently point the TFTP server at
/boot in the Pi’s root directory under NFS.
But first things first, we have to get the root directory onto the server first. The official guide is rather useless here. It assumes that we’re going to run the server off of another Pi, which we can conveniently copy the root from. I went the opposite direction. I set up the NFS server with the options
and, mounting the folder on the client Pi (with Raspbian installed to an SD card), copied the root with
rsync to the NFS folder. Conveniently enough, we can use the exact same folder and settings to point the Pi to later. (Having virtually no security on the root folder of the Pi’s filesystem is pretty concerning, however. I haven’t figured out how to get around this given the limitations of PXE booting on the Pi.)
Alright, so I now have a working Raspbian filesystem served over NFS, and I can point my TFTP server to
/boot as previously described. I do need to edit
/boot/cmdline.txt as described in the official guide to point the boot code towards the NFS server. Also best to edit
/etc/fstab and remove everything but
/proc, otherwise Raspbian thinks the boot didn’t succeed.
dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 root=/dev/nfs
nfsroot=10.0.1.102:/path/to/root,vers=3 rw ip=dhcp rootwait elevator=deadline
The bit starting with “root” is the important part. We need to point the boot code to the directory with the Pi’s root on the NFS server, as shown.
The remaining task is to get the DHCP server on the network to respond to the PI’s PXE discovery request. I fought
dnsmasq on Advanced Tomato for a long time, and finally settled on setting the appropriate DHCP fields by hand, as established in RFC 2132.
dhcp-option=43,Raspberry Pi Boot
Where the IP address belongs to the TFTP server. There are three spaces after “Boot” as suggested in the official guide, but I don’t know if they’re actually necessary. Surprisingly enough, these two options alone were enough to get it working—-I just set them on the DHCP page of Advanced Tomato.
The last step is just to make sure booting over ethernet is enabled on the Pi, as the official guide says. After that, removing the microSD card and rebooting, everything should just work!
01 March 2017
The term “fake news” has entered the modern parlance so quickly that it is worth beginning a discussion about fake news by trying to determine what, if anything, the term means. One way of investigating it is to try to identify a particularly clear case, rather than to propose a definition. Let me give what I take to be such a case.
Suppose there’s a website where the writers invent their stories, with no effort or intention of basing those stories on actual events. The articles are purely fictional, much like those found on satire sites like The Onion, but we find two critical differences when we look more closely. First, the articles on fake news sites are not intended to be satirical, nor do they contain typical markers of writing not intended to be taken seriously. Instead, they are written with the positive intent to deceive their audience. Second, these articles support and reinforce a particular (often extreme) political viewpoint, and tap into the zeitgeist in order to manipulate the public.
Now, one good reason to accept this as a paradigmatic case of fake news is that there actually are such sites. One receiving some attention in the mainstream press recently is the so-called “Denver Guardian,” run by a man successful enough to hire at least 20 writers. We read, even more worryingly, that children are incapable of reading a fake news article and a real news article and reliably distinguishing between them. We imagine a bleak future in which no one is able to tell true claims from false.
Another reason to take this view of fake news seriously is that everyone seems to accept it. The traditional news media has decried this apparent rejection of facts and has gone so far as to blame the election outcome (at least partially) on these sources of fake news. Facebook, under intense scrutiny and pressure, has shown interest in algorithms that either weed out or reduce the visibility of fake news sources.
The problem with fake news on this popular account is that unlike the occasional false story in the New York Times, it’s designed with the intent to mislead its audience. While, to be sure, even highly trained reporters will sometimes make mistakes, fake news is a kind of propaganda (though, in typical American fashion, it’s privatized).
Here is where I must say I’m rather skeptical of the intent-oriented account of fake news.
One reason to be worried is how easily talk of fake news morphs into blame-passing and mockery of conservatives. In this spirit, we see NPR note gleefully that some fake news writers “have tried to write fake news for liberals — but they just never take the bait.” Note also that insofar as the legitimate news media are able to pass blame for the election result, they direct attention away from their own culpability. Put aside for the moment how much (if any) blame the media deserves for putting Trump in the spotlight; realize first that this strategy has been wholly successful. Liberals everywhere are singing the praises of traditional news media, renewing (more likely, beginning!) subscriptions to the New York Times and Washington Post, and emphasizing the importance of a free press for democracy. (See this previous article on The Vim about how to criticize the media effectively.)
Of course, I’m not here to say that all these changes are unfortunate. Rather, in addition to emphasizing the crucial role of a free press in the face of an openly hostile administration, I think it’s crucial that we take a look at the role of the press in spreading misinformation, and diagnose more carefully the distinction between real and fake news.
Let’s take a look, first, at intent. A well credentialed reporter who tries to give a truthful account but is tripped up by unreliable sources or a subtle bias doesn’t seem to blame for the mistake. On the other hand, someone who writes deliberately false or misleading articles in order to reinforce a reader’s hatred for Hillary Clinton is deeply culpable for their act of lying. That said, in discussing fake news we usually are not trying to determine who’s to blame for various types of false statements, but rather to analyze the effect of the fake news phenomenon on the public. We’re trying to solve a practical problem, not a moral one.
One of the seeming benefits of the intent-based account of fake news is that it draws a bright line between fake news and real news. It also provides a very clear set of conditions for applying the term “fake news”: news is fake if it uses a made-up story to support a particular ideology. My core argument, however, is that these benefits evaporate when we’re trying to solve the practical problem I have stated. The reason for this is simple: the whole point of fake news (in the previous sense) is that it by definition is difficult to tell apart from real news. In fact I take a stronger view: it’s not possible for well-crafted fake news to be distinguished from real news except in terms of the apparent implausibility of its claims.
Implausibility is a tricky thing. We could insist on using it in an objective sense, but here it will be more natural and helpful to think about how what is plausible varies from person to person. Here, therefore, our practical problem becomes much more terrifying; the only hope for distinguishing fake news from real news relies on apparently subjective considerations.
Because of this, I suggest that our fixation on fake news can embolden the very sources of propaganda we attack. Think for a moment about what we’re telling the public on this account of fake news. We’re saying that their news sources are peppered with claims that are deliberately designed to deceive them. We’re telling them that they are unable to distinguish these false claims from true ones. Now, one might argue the situation isn’t as bad as all that. After all, the crucial difference is that these sources intend to mislead you, right? Surely mainstream news organizations have no reason to do that, right?
The problem, as I see it, is that Pandora’s box is open, and the trustworthiness of all of these organizations is up for grabs. Our appeals to plausibility carry no weight when our beliefs about what is plausible are so poorly aligned. Because of all this, Trump is free to throw all this talk back in our faces and say to a CNN reporter, “you’re fake news!”
It’s tempting, of course, to accuse Trump of simply misusing the term. Fake news, we might say, implies an intent to deceive, and CNN clearly has no such intent. What Trump ought to have said, we argue, is that CNN is false news, or that it sometimes says false things. I think this is deeply mistaken diagnosis of Trump’s purpose. Trump’s media agenda is precisely to cast doubt on the sincerity of the press. An ideal Trump supporter literally believes that the mainstream media is “fake news” — that they systematically lie about Trump in order to advance their own (liberal) agenda. That this seems so beyond the pale to us is precisely why it has so great a chance of success. We’re so blinded by the apparent implausibility of CNN’s being fake news that we don’t realize that many people take this claim quite seriously.
Before considering alternatives, let’s take a crucial step back. The fake news / real news dichotomy implied by the “intent” view is supported by a rather traditional take on what real news is. The latter, I suggest, hasn’t been plausible for decades now. Let me introduce this argument with a question: is Huffington Post “real news”? Thinking about the press from a certain traditionalist viewpoint, one would have to say certainly not. Their articles are informed by a center-left liberal viewpoint. At one point, they had an editor’s note at the bottom of articles about Donald Trump noting that he was a serial liar and misogynist. It’s equally clear, however, that Huffington Post is not fake news as typically construed. They are quite sincere about their liberal viewpoint. We could, of course, have a similar discussion about Fox News, MSNBC, and online-only news sites and blogs.
I think a better understanding of news media emphasizes the role that opinion plays in all of them. At a minimum, any news source will be affected by opinion in its reporting with regard to the news it emphasizes and ignores, the language it uses, and what it deems to be legitimate sources. One might argue that there’s still a core of news that remains purely objective: the direct reporting of recorded events. A newspaper might report, “Donald Trump told us so-and-so,” and if necessary, produce a recording of him saying it. I don’t wish to deny that there is some objective core to news, but note that Trump has disputed even basic facts like these. He’s denied saying things he was recorded saying; the faithful believe, and those on the edge are smoothed over with “Mr. Trump means he was taken out of context,” and we all move on to the next scandal.
With that in mind, let’s take another look at our predicament. The practical problem is that the standard view of fake news proclaims that most people aren’t capable of telling real news from fake news. What’s worse, reliably distinguishing real news from fake news requires interpreting the intent of one’s source, which ultimately necessitates a grasp of what is *plausible. I argue that this view fails to give us ways to solve this problem. While it’s certainly true that certain news is fake news in the proposed sense, i.e. that it consists (at worst) in completely fabricated stories, the distinction does not cut across the information people accept in any actionable way.
Here I insert a joke: the reason the fake news writers couldn’t get liberal readers to bite on their stories is that those readers were already subscribed to the New York Times.
Consider again the culpability of the mainstream media in their hyping of Trump (scandals and all) throughout the campaign, which gave him countless millions of dollars in free screen time. It would be wrong to suggest, of course, that the mainstream media was a deliberate propaganda machine on behalf of Trump, but these facts also belie the idea that the media is truly interested in accurately representing the facts to us. Systematically focusing on one candidate or type of story to the detriment of all others is as serious a bias as any. As I argued earlier, it’s a crucial symptom of opinion in journalism when certain decisions are made about which stories to cover and which to drop.
In its never-ending focus on Clinton’s email “scandal”, the mainstream press created the mistaken notion that she was a hopelessly flawed and corrupt candidate. Of course this doesn’t qualify as fake news under the original definition at all; the media did not say anything intended to be false (or anything strictly false at all), only continually engaging in never-ending false controversy. One might think that the “coverage is always good” dictum applies to Clinton equally as well as Trump, but this is not quite true. Coverage is only good if you encourage the belief that the mainstream media perpetually lies about you, and you have supporters willing to believe it. Every negative thing that the media published about Trump was either “lies” or just further proof that the press wanted to destroy his candidacy.
Many in the public ended up believing that Clinton and Trump were comparable in terms of their flaws as candidates. This doesn’t have to be a reasonable belief or survive very much serious inquiry (indeed it does not). It only has to exist in the space of things one can say without being laughed at by nearly everyone. I call this space the *discourse horizon. It’s of fundamental importance in public thought, and it’s partially created by the media. Of course, it also has a corresponding effect on what the media can and cannot say. Journalism can locate something within the discourse horizon simply by presenting it as up for debate. So, as a result, the public feels that “GMOs cause cancer” is a legitimate belief, while “NASA faked the moon landing” is not.
I suggested previously that opinion plays a role in all journalism. I think recent years have seen a vast increase in the amount of opinion pieces available to, and read by, the public. These too can have an effect on the space of acceptable beliefs. Even more traditional media often blurs the line between its traditional journalism and opinion pieces. I frequently find it hard to tell on some sites when a piece is original reporting and when it is an opinion piece (on Slate for example). This means, from the public’s point of view, it’s often enough to find one or two people who are willing to state publicly the thing you’d like to believe.
There are, of course, many varying degrees of opinion in journalism. Fake news, in the received sense, hardly counts as opinion at all, since it is written without regard to the truth of the claims it makes. Editorials, and opinion-friendly sources like Huffington Post, explicitly endorse a particular political viewpoint. The mainstream news is written from an apparently objective perspective, but in fact is affected by opinion in a variety of hidden ways. I think a crucial point about “fake news” is that it’s a very tiny portion of the giant media buffet. It’s certainly true that there are a small number of sites that make up absurd stories for advertizing revenue, but they have a relatively small impact on the media diet of the vast majority. Most articles are quite sincere. What really counts is just how much opinion is available, and crucially, the fact that you can find an opinion piece that validates nearly any of your opinions.
The accepted solution to this problem is fact-checking, of course. If you read something from an opinion piece or unknown source, you should look it up on FactCheck or try to find a corroborating source. If this is the solution, then what we need to do is teach the public media literacy.
I think what I have said already should cast doubt on this solution. First, there are valid questions about whether the mainstream media itself is trustworthy. They not only misrepresented the nature of the election, thereby making them partially responsible for the Trump phenomenon, they are also limited by, and responsible for their part in creating, the discourse horizon. Furthermore, their financial interest in presenting controversy and attracting viewers regularly compromises them, as we saw when the Washington Post recently reported that Russia had hacked a power station in Vermont. Second, I question the efficacy of the fact-checking solution when the portion of the public we are concerned about is forced to choose between competing sources of information and the legitimacy of traditional journalism is up for grabs.
I have a much darker suggestion to make about the people who believe fake news. Much of it, the “Pizzagate” story for example, is so outlandish and unbelievable that it’s almost inconceivable that anyone could seriously believe it. So I suggest that most of them don’t believe it. The immediate question that arises for them is not whether the statement is true, but rather whether it contains the correct value judgment about its subject. To the Trump voter, Clinton is nasty, despicable, and morally rotten. That’s exactly the sort of thing she would do! Sharing the article is an invitation to one’s friends to wink together at it, to join with others in pretending to believe the lie.
Trump voters aren’t unique in this regard. We saw much the same thing very recently in Trump’s “golden shower” controversy. The whole story came from a single unsubstantiated report published by Buzzfeed. It sounds incredibly unlikely. Do some people really believe it? Maybe. The point, however, for most people who shared the story was not whether it was true but rather it said the right kinds of things about (and provided an opportunity to mock) Trump. Liberals take solace in the fact that Trump is not merely evil and ignorant but a pervert.
Even conspiracy theories are present among liberals. A survey found that half of Clinton voters believe that Russia hacked the election vote counts. It’s absurd and obviously false, and (crucially) as far from reality as anything on a fake news site.
I think that there is little hope of solving this problem through media literacy. Not only is “fake news” only part of what I take to be a much larger problem, there is little practical hope for convincing Trump supporters to take traditional media seriously. Not only do they frequently not care whether the story is true, they also have serious doubts (encouraged by Trump himself) about the good intentions of mainstream reporters. It does no good to tell them to verify facts with trustworthy sources when what counts as a trustworthy source is itself up for grabs.
What I would like to do, therefore, is to offer an alternative account of fake news and some steps towards a real solution to the problem it poses.
The received view of fake news is correct to portray it as fundamentally opposed to fact-based journalism, but is wrong about why. Traditional journalism is a journalism that is keyed to the truth; it has as its one supreme goal representing reality accurately to the general public. Fake news is news that is not so keyed; it has some other goal which can, and often does, interfere with the accurate presentation of facts. On this account, there are elements other than the intentions of journalists at play. Fake news can exist at The Guardian just as well as the Denver Guardian. Whenever there is a systematic force that causes certain facts to be misrepresented (or over-or-under-represented), we are dealing with fake news. Now we begin to see that fake news is all around us. The mainstream media’s obsession with Clinton’s email server was not, on the previous view, “fake news” because (a) it reported on actual facts, and (b) the intention of the reporters was not to mislead. I offer the following rebuttal: that this reporting led many to believe that Clinton was hopelessly corrupt was no accident. Instead, we have a clear cut case of what happens when systemic concerns other than accurately representing the truth to the public take priority. The Clinton story was fake news on my account precisely because these systemic forces led the mainstream media to mislead the public with a constant barrage of (largely accurate) stories about what was ultimately a minor issue with Clinton’s qualifications. Media today is driven by controversy and outrage (and the financial interests of corporations), not truthful reporting.
When we use the term “fake news” in my suggested sense, we refer to anything that pretends to be news, where news is understood normatively as a truth-informing enterprise. The key problem with the received view of fake news is that it focuses on only a single way in which journalism can be warped away from the truth (ill intent), and misses a variety of other systemic interests which pervert even traditional journalism. Worse still, its single-minded focus on intent provides room for critics of journalism like Trump to claim that mainstream news is “fake”. We must therefore avoid scaremongering made-up news (a relatively small phenomenon), and instead focus on the many other ways in which news can be fake.
This account provides the beginnings of another conversation about fake news. What are these systemic forces? How can we fight them? What the original account of fake news surely got right was that sometimes propaganda is at work and the author deliberately tries to mislead us. My account suggests that there are other forces just as crucial: the profit motive, the constant need for advertizing revenue and “clicks”; these can all bend reporting away from the truth. I think that to fight one of these we must fight them all.
One benefit of this approach is that it provides us with some common ground with the Trump supporter who is skeptical of the mainstream media. If I’m right, we should be skeptical. The solution can only be openness on both sides to reforming our institutions.
We must also be aware that people who “believe” fake news are not always deceived. They share articles they know (or strongly suspect) to be false not because they are deluded but because these articles are the only ones that support their value system. Their alternatives — believing absurd claims or facing up to a cruel reality — are both terrifying. Our approach to their condition must begin with empathy, and remembering that we too are susceptible to this problem. If I’m right, we’re all trapped by the discourse horizon. What we need to find, together, is an alternative.
This post was co-published on The Vim
22 March 2015
In today’s New York Times, Judith Shulevitz wrote an article criticizing “safe spaces” in universities, arguing that they’re too often an excuse to insulate students from ideas they don’t like. If you’re reading this post, you should read Shulevitz’s article first.
I have two main criticisms of the article, and one general point of agreement. Let’s think through the criticisms first.
First, Shulevitz conflates “safe spaces” with “insulation” against potentially upsetting speech. We don’t put trigger warnings on articles because we’re afraid of hurting oversensitive college students, we put trigger warnings on articles when there is a possibility that someone who has experienced sexual assault or other trauma will unexpectedly have to face painful memories.
It’s important to keep these distinct. Students at large may not deserve to be protected from speech they disagree with, but people who have diagnosable psychological trauma in response to certain subjects (often even when those subjects are broached positively) should be warned and given the opportunity to avoid being present. Throughout the article, Shulevitz routinely ignores this distinction. She says that “Safe spaces are an expression of the conviction, increasingly prevalent among college students, that their schools should keep them from being ‘bombarded’ by discomfiting or distressing viewpoints.” I think this is very shortsighted.
In fairness to Shulevitz, she’s not the only person making this mistake. In the article, she quotes Emma Hall (a rape survivor who helped run the safe space at Brown University) as saying “I was feeling bombarded by a lot of viewpoints that really go against my dearly and closely held beliefs.” One could argue that Emma Hall is insulating herself from “distressing viewpoints”; even as a survivor, she’s capable of bad motives. Shulevitz’s mistake is to frame all advocates for safe spaces as insulating themselves intellectually, but what they are actually attempting is to protect people psychologically from material to which they are sensitive because of the emotional damage of traumatic events.
My second concern with the article is its mistaking advocacy for safe spaces with complaints about the non-representation of women in debates. It incorrectly characterizes them both as examples of students avoiding intellectual criticism for emotional reasons. In fact, there are very good reasons for worrying about an all-male debate of abortion, distinct from both this tendency and the need to provide safe spaces.
Suppose that a university held a debate on “climate change,” hosting both an expert on climate change from the IPCC and a well-known blogger who doesn’t believe in climate change. Now, it’s likely that many students who care about the environment would disapprove of this debate, and they might even frame it in terms of “mental safety”. But what they’re worried about is not hearing views that oppose their own, it’s a different problem altogether.
The problem with hosting a blogger who doesn’t accept climate change is that the blogger has no relevant scientific credentials. In hosting a debate, the university implicitly indicates that both speakers are relevant experts and should be heard and judged merely on the merits of what they say. Of course this is completely untrue: we have no reason to believe that the blogger is an expert on climate change. We shouldn’t weigh what an expert and non-expert have to say equally.
Furthermore, as non-experts, we’re not fully capable of accurately comparing the two speakers purely on the merits of their words. In practice, coming to accept (or reject) climate change occurs when one learns about climate change. Unless one is capable of weighing the relevant facts, one can only trust experts in the field. This means that the whole idea of a debate is a bit silly, and distracts us from what ultimately determines our beliefs. If the debate is a farce between the uninformed, and the audience is unable to distinguish between the two, there’s good reason to worry that the result is mentally unhealthy.
Now, with abortion, emotions are a key aspect of the problem. It’s not possible to say, externally, exactly what a woman faces when carrying an unwanted potential child. Moreover, it’s impossible to say in general what it’s like to walk around with two X chromosomes when one doesn’t have them. But this makes a debate about abortion between men (however intellectually honest they may be) inherently problematic. They are (in the language of the climate change example) not experts in a central aspect of the “debate” on abortion. However empathetic they may be, some emotions are sui generis and male debaters are not qualified to speak about them.
There is a legitimate worry, therefore, that a debate about abortion between two men is a farce. We have reason to fear that an audience will be swayed by non-factual elements of the debate, rather than by certain relevant facts that the speakers don’t themselves know.
I could take the time to complain about several similar examples in the article (the dismissal of Muslim concerns about Charlie Hebdo comes to mind), but I will leave that out of this post. Also, I should preface the succeeding thoughts with the note that I’m white with a Y chromosome, and have never experienced prejudice against either. Thus, it’s possible that I am currently blind to areas in which some people legitimately need to be protected from certain words or modes of discourse.
I think that Shulevitz is right to worry about over-sensitivity, and she accurately pegs college as a time when we should especially be challenged by ideas that upset us. There is, of course, nothing wrong with a debate between Jessica Valenti and Wendy McElroy (and it’s rather funny to suggest that Valenti — a feminist herself — would be part of something problematic). Likewise, it seems nonsensical to suggest that we censor Huckleberry Finn. Students don’t deserve protection from words or ideas, and in fact “protecting them” actually hurts their development.
Universities have long been the places where young people can develop in an open, intelligent, and rigorous environment. I agree with Shulevitz that it’s very important to protect this environment from political correctness and “self-infantilization”. However, in doing so, it’s crucial that we actually be rigorous; when talking about contentious issues, we need to ensure that the speakers are relevant experts. Likewise, to keep debate open, we need to make sure that everyone, especially those with direct experience, are welcome. If that means speaking more kindly — or even creating explicitly “unsafe” spaces when necessary — so be it.