[Replicant] [PATCH 3/9] freedom-privacy-security-issues: Improve the bootrom description.

Thu Mar 3 10:59:29 UTC 2016

Le mercredi 02 mars 2016 à 20:28 +0100, Denis 'GNUtoo' Carikli a écrit :
> Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo at no-log.org>

See comments below.

> ---
>  freedom-privacy-security-issues.php | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/freedom-privacy-security-issues.php b/freedom-privacy-security-
> issues.php
> index 75a055b..faa9218 100644
> --- a/freedom-privacy-security-issues.php
> +++ b/freedom-privacy-security-issues.php
> @@ -7,7 +7,7 @@
>  			<p>Mobile devices such as phones and tablets are
> taking and increasingly important part in our computing, hence they are
> particularly subject to freedom and security concerns. These devices are
> actually full computers with powerful hardware, running complete operating
> systems that allow for updates, software changes and installable applications:
> this makes it easy to run <a href="//www.gnu.org/philosophy/free-sw.html">free
>  software</a> on them. Mobile devices are often used for communications and
> provide hardware features that are sensitive when it comes to privacy and
> security: GPS, camera, microphone, etc, in addition to storing the user's
> data. Hence, they are particularly subject to being used to spy on the
> user.</p>
>  			<h3>A simplified overview of mobile devices</h3>
>  			<p><a href="images/freedom-privacy-security-
> issues/hardware.png" data-lightbox="overview" data-title="Hardware-side
> overview"><img src="images/freedom-privacy-security-issues/hardware.png"
> alt="Hardware-side overview" style="width: 250px; float: left;"/></a>On the
> hardware side, mobile devices are built with a system on a chip (SoC) that
> includes a processor (CPU) and various other fundamental components, around
> which are found various integrated circuits, memory (RAM), storage, user
> input/output (I/O), etc. When the device is telephony-enabled, it also
> features a modem, which is the component in charge of dealing with the mobile
> telephony network. Nowadays, it is usually has a powerful processor, with
> dedicated memory and sometimes storage.</p>
> -			<p>Regarding the software side of things on mobile
> devices, the main CPU (inside the SoC) starts by executing initial boot code,
> often known as the bootrom. This code will look up various places such as
> NAND, eMMC or MMC (sd/micro sd card) storage, depending on the hardware
> configuration, to load a bootloader. The bootloader, which is in fact often
> split in different stages, is in charge of bringing up and configuring various
> aspects of the hardware and eventually starting the operating system by
> loading and running its kernel.<br /><a href="images/freedom-privacy-security-
> issues/software.png" data-lightbox="overview" data-title="Software-side
> overview"><img src="images/freedom-privacy-security-issues/software.png"
> alt="Software-side overview" style="width: 250px; float: right;"/></a>The
> kernel itself, among other things, deals with the hardware directly and
> provides ways for other programs (running in user-space) to access it. In
> user-space, hardware abstraction layers are progr
>  ams specific to each device that know how to properly drive the hardware.
> They use the kernel to communicate back and forth with the hardware and
> implement the proper protocols for it.<br /><br />The actual knowledge of how
> to drive the hardware is split between the kernel and the hardware abstraction
> layer libraries: both are needed to make it work properly. Hardware
> abstraction layers provide a generic interface for the framework to use. The
> framework itself provides an interface for applications that is independent of
> the device and the hardware. That way, applications can access hardware
> features through the generic framework interface, which will call the hardware
> abstraction layer libraries, ending up with the kernel communicating with the
> hardware.</p>
> +			<p>Regarding the software side of things on mobile
> devices, the main CPU (inside the SoC) starts by executing code located inside
> the silicon.

Maybe specify "inside the chip's silicon", because it is technically also on
silicon when it's in external memory. It would also be a good a idea to emphasis
that it can't be changed, it's probably not obvious to everyone. So maybe
instead of "located", "stored read-only" would be a better fit.

>  If this is an ARM CPU, that code will be ARM instructions.

Can you elaborate why that precision is necessary? I think it's already clear
that the code is executed by the CPU (and too much redundancy is not always a
good thing, especially given that the text is already long).

>  This code is known as the botrom.

Looks like a typo, should be "bootrom".

>  It will look up various places such as NAND, eMMC or MMC (sd/micro sd card)
> storage, depending on the hardware configuration, to load a bootloader. The
> bootloader, which is in fact often split in different stages, is in charge of
> bringing up and configuring various aspects of the hardware and eventually
> starting the operating system by loading and running its kernel.<br /><a
> href="images/freedom-privacy-security-issues/software.png" data-
> lightbox="overview" data-title="Software-side overview"><img
> src="images/freedom-privacy-security-issues/software.png" alt="Software-side
> overview" style="width: 250px; float: right;"/></a>The kernel itself, among
> other things, deals with the hardware directly and provides ways for other
> programs (running in user-s
>  pace) to access it. In user-space, hardware abstraction layers are programs
> specific to each device that know how to properly drive the hardware. They use
> the kernel to communicate back and forth with the hardware and implement the
> proper protocols for it.<br /><br />The actual knowledge of how to drive the
> hardware is split between the kernel and the hardware abstraction layer
> libraries: both are needed to make it work properly. Hardware abstraction
> layers provide a generic interface for the framework to use. The framework
> itself provides an interface for applications that is independent of the
> device and the hardware. That way, applications can access hardware features
> through the generic framework interface, which will call the hardware
> abstraction layer libraries, ending up with the kernel communicating with the
> hardware.</p>
>  			<p>Many other components of a mobile device also run
> software in different forms. The various integrated circuits run small pieces
> of dedicated software that are called firmwares. When the device is telephony-
> enabled, there is also software running on the modem. Modern modems are
> complex and run full operating systems.</p>
>  			<h3>The current situation of freedom and
> privacy/security on mobile devices</h3>
>  			<p>A mobile device respecting the users' freedom
> would have:<ul><li>Free hardware</li><li>Free firmwares</li><li>Free modem
> system</li><li>Free bootrom and bootloader</li><li>Free system and
> applications</li></ul>Regarding <a href="#free-hardware">free hardware</a>, it
> doesn't quite exist as of today, or barely. Modifying hardware is nearly
> impossible: new versions of the hardware have to be produced, and those are
> expensive. While producing printed circuit boards (PCBs) costs a lot of money,
> producing integrated circuits is out of reach. A few devices come with
> schematics for the PCB, but that's usually as far as it gets. Hence, totally-
> free hardware doesn't exist yet.</p>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: This is a digitally signed message part
URL: <http://lists.osuosl.org/pipermail/replicant/attachments/20160303/cfef5496/attachment.asc>