[Replicant] [PATCH 2/9] freedom-privacy-security-issues: Improve the modem definition.

[Paul Kocialkowski]

Le mercredi 02 mars 2016 à 20:28 +0100, Denis 'GNUtoo' Carikli a écrit :
> I don't know any GSM baseband that can run without their own
> memory.

I agree, when shared memory is used, it's for communication with the main
processor, not as main memory for the modem.

Could you drop the final point in the subject? This is also for all the
following patches you sent.

See comments below.

> Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo at no-log.org>
> ---
>  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 4587cfb..75a055b 100644
> --- a/freedom-privacy-security-issues.php
> +++ b/freedom-privacy-security-issues.php
> @@ -6,7 +6,7 @@
>  		 <div class="col-md-9">
>  			<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 a powerful processor, sometimes
> with its own memory and storage.</p>
> +			<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

Either "is" or "has" should be remove here. To be more accurate, how about
something like:

"Nowadays, it usually embeds a powerful processor, with dedicated memory and
sometimes storage."

I suppose the modem "is" not the processor (it probably has controllers too
within the chip), and saying that it "has" a processor makes it sound like the
processor is somewhat external to it.

>  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>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>
-------------- 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/20160303/6718e9b7/attachment.asc>