[Replicant] [PATCH 4/9] freedom-privacy-security-issues: Add an example of where the hardware knowledge is.

[Denis 'GNUtoo' Carikli]

Many people do think that the hardware knowledge is only in the kernel.
This is to prevent confusion.

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 faa9218..65fc54a 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 code located inside the silicon. If this is an ARM CPU, that code will be ARM instructions. This code is known as the botrom. 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 i
 n 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>Regarding the software side of things on mobile devices, the main CPU (inside the SoC) starts by executing code located inside the silicon. If this is an ARM CPU, that code will be ARM instructions. This code is known as the botrom. 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 i
 n 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. For instance, when making a call, the dialer application will communicate with the framework, which in turn will communicate with the hardware abstract
 ion laye
 r. That hardware abstraction layer will implement the protocol to speak with the modem, and the Linux kernel will be responsible of permitting the communication between the hardware abstraction layer and the modem.</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>
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