[bootlin/training-materials updates] master: Small improvements to kernel porting slides (7619c897)
Michael Opdenacker
michael.opdenacker at bootlin.com
Mon Mar 18 15:50:27 CET 2019
Repository : https://github.com/bootlin/training-materials
On branch : master
Link : https://github.com/bootlin/training-materials/commit/7619c897660ff8d85e2faf34e46baa0b72a4d3e4
>---------------------------------------------------------------
commit 7619c897660ff8d85e2faf34e46baa0b72a4d3e4
Author: Michael Opdenacker <michael.opdenacker at bootlin.com>
Date: Mon Mar 18 15:50:27 2019 +0100
Small improvements to kernel porting slides
Signed-off-by: Michael Opdenacker <michael.opdenacker at bootlin.com>
>---------------------------------------------------------------
7619c897660ff8d85e2faf34e46baa0b72a4d3e4
slides/kernel-porting-content/kernel-porting-content.tex | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/slides/kernel-porting-content/kernel-porting-content.tex b/slides/kernel-porting-content/kernel-porting-content.tex
index 6466e497..ebe70f05 100644
--- a/slides/kernel-porting-content/kernel-porting-content.tex
+++ b/slides/kernel-porting-content/kernel-porting-content.tex
@@ -55,7 +55,7 @@
\begin{itemize}
\item Until 2011, the ARM architecture wasn't using the Device Tree,
and a large portion of the SoC support was located in
- \code{arch/arm/mach-<foo>}.
+ \code{arch/arm/mach-<soc>}.
\item Each board supported by the kernel was associated to an unique
{\em machine ID}.
\item The entire list of {\em machine ID} can be downloaded at
@@ -67,6 +67,8 @@
\item The bootloader had to pass the {\em machine ID} to the kernel
in a specific ARM register.
\end{itemize}
+ This way, the kernel knew what board it was booting on,
+ and which init callbacks he had to execute.
\end{frame}
\begin{frame}
@@ -78,14 +80,14 @@
C code to describe SoCs and boards, a specialized language is
used.
\item Second, many driver infrastructures were created to replace
- custom code in \code{arch/arm/mach-<foo>}:
+ custom code in \code{arch/arm/mach-<soc>}:
\begin{itemize}
\item The common clock framework in \kdir{drivers/clk}
\item The pinctrl subsystem in \kdir{drivers/pinctrl}
\item The irqchip subsystem in \kdir{drivers/irqchip}
\item The clocksource subsystem in \kdir{drivers/clocksource}
\end{itemize}
- \item The amount of code in \code{mach-<foo>} has now significantly
+ \item The amount of code in \code{mach-<soc>} has now significantly
reduced.
\end{itemize}
\end{frame}
@@ -145,8 +147,8 @@
\mint[fontsize=\small]{perl}+model = "Crystalfontz CFA-10036 Board";+
\end{block}
\item A list of {\em compatible} strings, from the most specific one
- to the most general one. Can be used by kernel code to do a SoC or
- board-specific check.\\
+ to the most general one. Mandatory to execute the right SoC specific
+ initializations and board specific code.\\
\begin{block}{}
\mint[fontsize=\small]{perl}+compatible = "crystalfontz,cfa10036", "fsl,imx28";+
\end{block}
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