[FE training-materials-updates] Flash filesystem labs: warn about read-only partitions

Michael Opdenacker michael.opdenacker at free-electrons.com
Mon Nov 25 09:33:22 CET 2013


Repository : git://git.free-electrons.com/training-materials.git

On branch  : master
Link       : http://git.free-electrons.com/training-materials/commit/?id=724d57c6a6f51bbfccf2e6700844508e79635339

>---------------------------------------------------------------

commit 724d57c6a6f51bbfccf2e6700844508e79635339
Author: Michael Opdenacker <michael.opdenacker at free-electrons.com>
Date:   Mon Nov 25 09:30:43 2013 +0100

    Flash filesystem labs: warn about read-only partitions
    
    - Remove the "ro"/"rw" labels from the partitions chart
    - Warn that the rootfs partition will have to be declared
      as read-write, not read-only.
    
    Signed-off-by: Michael Opdenacker <michael.opdenacker at free-electrons.com>


>---------------------------------------------------------------

724d57c6a6f51bbfccf2e6700844508e79635339
 labs/sysdev-flash-filesystems/flash-map.dia        |   45 +++++++++-----------
 .../sysdev-flash-filesystems.tex                   |   10 +++--
 2 files changed, 26 insertions(+), 29 deletions(-)

diff --git a/labs/sysdev-flash-filesystems/flash-map.dia b/labs/sysdev-flash-filesystems/flash-map.dia
index ed699df..25416ed 100644
--- a/labs/sysdev-flash-filesystems/flash-map.dia
+++ b/labs/sysdev-flash-filesystems/flash-map.dia
@@ -322,13 +322,12 @@
         <dia:point val="18.7,10.025"/>
       </dia:attribute>
       <dia:attribute name="obj_bb">
-        <dia:rectangle val="18.1491,9.5525;19.2509,10.78"/>
+        <dia:rectangle val="18.1491,9.53769;19.2658,10.1746"/>
       </dia:attribute>
       <dia:attribute name="text">
         <dia:composite type="text">
           <dia:attribute name="string">
-            <dia:string>#MLO
-(ro)#</dia:string>
+            <dia:string>#MLO#</dia:string>
           </dia:attribute>
           <dia:attribute name="font">
             <dia:font family="sans" style="0" name="Helvetica"/>
@@ -356,13 +355,12 @@
         <dia:point val="20.7,10.025"/>
       </dia:attribute>
       <dia:attribute name="obj_bb">
-        <dia:rectangle val="19.8478,9.5525;21.5522,10.78"/>
+        <dia:rectangle val="19.8478,9.53769;21.567,10.1746"/>
       </dia:attribute>
       <dia:attribute name="text">
         <dia:composite type="text">
           <dia:attribute name="string">
-            <dia:string>#U-Boot
-(ro)#</dia:string>
+            <dia:string>#U-Boot#</dia:string>
           </dia:attribute>
           <dia:attribute name="font">
             <dia:font family="sans" style="0" name="Helvetica"/>
@@ -390,14 +388,13 @@
         <dia:point val="23.075,10.2"/>
       </dia:attribute>
       <dia:attribute name="obj_bb">
-        <dia:rectangle val="22.2228,9.26875;23.9272,11.1312"/>
+        <dia:rectangle val="22.2228,9.56403;23.942,10.836"/>
       </dia:attribute>
       <dia:attribute name="text">
         <dia:composite type="text">
           <dia:attribute name="string">
             <dia:string>#U-Boot
-env
-(ro)#</dia:string>
+env#</dia:string>
           </dia:attribute>
           <dia:attribute name="font">
             <dia:font family="sans" style="0" name="Helvetica"/>
@@ -406,7 +403,7 @@ env
             <dia:real val="0.63499997556209564"/>
           </dia:attribute>
           <dia:attribute name="pos">
-            <dia:point val="23.075,9.74125"/>
+            <dia:point val="23.075,10.0513"/>
           </dia:attribute>
           <dia:attribute name="color">
             <dia:color val="#000000"/>
@@ -479,13 +476,12 @@ env
         <dia:point val="27.225,10"/>
       </dia:attribute>
       <dia:attribute name="obj_bb">
-        <dia:rectangle val="26.4271,9.38625;28.0229,10.6137"/>
+        <dia:rectangle val="26.4271,9.68153;28.0377,10.3185"/>
       </dia:attribute>
       <dia:attribute name="text">
         <dia:composite type="text">
           <dia:attribute name="string">
-            <dia:string>#Kernel
-(ro)#</dia:string>
+            <dia:string>#Kernel#</dia:string>
           </dia:attribute>
           <dia:attribute name="font">
             <dia:font family="sans" style="0" name="Helvetica"/>
@@ -494,7 +490,7 @@ env
             <dia:real val="0.63499997556209564"/>
           </dia:attribute>
           <dia:attribute name="pos">
-            <dia:point val="27.225,9.85875"/>
+            <dia:point val="27.225,10.1688"/>
           </dia:attribute>
           <dia:attribute name="color">
             <dia:color val="#000000"/>
@@ -564,13 +560,12 @@ env
         <dia:point val="24.7,10"/>
       </dia:attribute>
       <dia:attribute name="obj_bb">
-        <dia:rectangle val="24.1762,9.38625;25.2237,10.6137"/>
+        <dia:rectangle val="24.1762,9.68153;25.2386,10.3185"/>
       </dia:attribute>
       <dia:attribute name="text">
         <dia:composite type="text">
           <dia:attribute name="string">
-            <dia:string>#DTB
-(ro)#</dia:string>
+            <dia:string>#DTB#</dia:string>
           </dia:attribute>
           <dia:attribute name="font">
             <dia:font family="sans" style="0" name="Helvetica"/>
@@ -579,7 +574,7 @@ env
             <dia:real val="0.63499997556209564"/>
           </dia:attribute>
           <dia:attribute name="pos">
-            <dia:point val="24.7,9.85875"/>
+            <dia:point val="24.7,10.1688"/>
           </dia:attribute>
           <dia:attribute name="color">
             <dia:color val="#000000"/>
@@ -736,14 +731,13 @@ env
         <dia:point val="30.85,10"/>
       </dia:attribute>
       <dia:attribute name="obj_bb">
-        <dia:rectangle val="29.545,9.06875;32.155,10.9312"/>
+        <dia:rectangle val="29.545,9.36403;32.1698,10.636"/>
       </dia:attribute>
       <dia:attribute name="text">
         <dia:composite type="text">
           <dia:attribute name="string">
             <dia:string>#Root
-filesystem
-(ro)#</dia:string>
+filesystem#</dia:string>
           </dia:attribute>
           <dia:attribute name="font">
             <dia:font family="sans" style="0" name="Helvetica"/>
@@ -752,7 +746,7 @@ filesystem
             <dia:real val="0.63499997556209564"/>
           </dia:attribute>
           <dia:attribute name="pos">
-            <dia:point val="30.85,9.54125"/>
+            <dia:point val="30.85,9.85134"/>
           </dia:attribute>
           <dia:attribute name="color">
             <dia:color val="#000000"/>
@@ -771,13 +765,12 @@ filesystem
         <dia:point val="38.3,10"/>
       </dia:attribute>
       <dia:attribute name="obj_bb">
-        <dia:rectangle val="36.3062,9.38625;40.2937,10.6137"/>
+        <dia:rectangle val="36.3062,9.68153;40.3086,10.3185"/>
       </dia:attribute>
       <dia:attribute name="text">
         <dia:composite type="text">
           <dia:attribute name="string">
-            <dia:string>#Data filesystem
-(rw)#</dia:string>
+            <dia:string>#Data filesystem#</dia:string>
           </dia:attribute>
           <dia:attribute name="font">
             <dia:font family="sans" style="0" name="Helvetica"/>
@@ -786,7 +779,7 @@ filesystem
             <dia:real val="0.63499997556209564"/>
           </dia:attribute>
           <dia:attribute name="pos">
-            <dia:point val="38.3,9.85875"/>
+            <dia:point val="38.3,10.1688"/>
           </dia:attribute>
           <dia:attribute name="color">
             <dia:color val="#000000"/>
diff --git a/labs/sysdev-flash-filesystems/sysdev-flash-filesystems.tex b/labs/sysdev-flash-filesystems/sysdev-flash-filesystems.tex
index 5431f88..42534cb 100644
--- a/labs/sysdev-flash-filesystems/sysdev-flash-filesystems.tex
+++ b/labs/sysdev-flash-filesystems/sysdev-flash-filesystems.tex
@@ -100,9 +100,13 @@ sources: (\code{arch/arm/boot/dts/omap3-igep0020.dts})
 Set the \code{bootargs} variable so that:
 
 \begin{itemize}
-\item you define the 7 MTD partitions, as detailed previously
-\item the root filesystem is mounted from the 6\textsuperscript{th}
-  partition, and is mounted read-only (kernel parameter \code{ro})
+\item You define the 7 MTD partitions, as detailed previously
+\item The root filesystem is mounted from the 6\textsuperscript{th}
+  partition, and is mounted read-only (kernel parameter \code{ro}).
+  {\bf Important: even if this partition is mounted read-only, the
+  MTD partition itself must be declared as read-write. Otherwise,
+  Linux won't be able to perform ECC checks on it, which involve
+  both reading and writing.}
 \end{itemize}
 
 Boot the target, check that MTD partitions are well configured, and



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