Merge branch 'master' into develop

1 files changed, 88 insertions, 19 deletions

diff --git a/dev/c/system.html b/dev/c/system.html
index de9dab5..d1d6558 100644
--- a/dev/c/system.html
+++ b/dev/c/system.html
@@ -15,35 +15,87 @@
         will run on and GDB will connect to it to help us
         understand how things tick.</p>
 
-        <h2>Kernel Build</h2>
+        <h2>Build Kernel</h2>
 
         <pre>
-        $ tar xf linux-4.9.48.tar.xz
-        $ cd linux-4.9.48
+        $ tar xf linux-4.9.258.tar.xz
+        $ cd linux-4.9.258
         </pre>
 
         <p>Default configuration disable some security
         configurations that allow us to debug (random memory
-        layout).</p>
+        layout KALSR),  CONFIG_COMPAT_BRK don't randomize
+        position of the programs (randomize_va_space) useful when
+        debugging a program (<a href="tracing.html">tracing</a>).
+        Configuration flags to enable;</p>
+
+        <ul>
+            <li>CONFIG_64BIT</li>
+            <li>CONFIG_DEBUG_KERNEL</li>
+            <li>CONFIG_HAVE_ARCH_KGDB</li>
+            <li>CONFIG_FTRACE</li>
+            <li>CONFIG_PRINTK</li>
+            <li>CONFIG_BLK_DEV_INITRD</li>
+            <li>CONFIG_BINFMT_ELF</li>
+            <li>CONFIG_TTY</li>
+            <li>CONFIG_DEBUG_INFO</li>
+            <li>CONFIG_DEBUG_INFO_DWARF4</li>
+            <li>CONFIG_GDB_SCRIPTS</li>
+            <li>CONFIG_READABLE_ASM</li>
+            <li>CONFIG_FRAME_POINTER</li>
+            <li>CONFIG_KGDB</li>
+            <li>CONFIG_KGDB_LOW_LEVEL_TRAP</li>
+            <li>CONFIG_EARLY_PRINTK</li>
+            <li>CONFIG_COMPAT_BRK</li>
+        </ul>
+
+        <p>And to disable;</p>
+
+        <ul>
+            <li>CONFIG_CC_OPTIMIZE_FOR_SIZE</li>
+        </ul>
+
+
+        <p>This changes can be achieved by creating a config-fragment and then
+        merge it with the configuration.</p>
 
         <pre>
-        $ make x86_64_defconfig
+        $ cat &lt;&lt;EOF &gt;.config-fragment
+        CONFIG_64BIT=y
+        CONFIG_DEBUG_KERNEL=y
+        CONFIG_HAVE_ARCH_KGDB=y
+        CONFIG_COMPAT_BRK=y
+        CONFIG_FTRACE=y
+        CONFIG_PRINTK=y
+        CONFIG_BLK_DEV_INITRD=y
+        CONFIG_BINFMT_ELF=y
+        CONFIG_TTY=y
+        CONFIG_DEBUG_INFO=y
+        CONFIG_DEBUG_INFO_DWARF4=y
+        CONFIG_GDB_SCRIPTS=y
+        CONFIG_READABLE_ASM=y
+        CONFIG_FRAME_POINTER=y
+        CONFIG_KGDB=y
+        CONFIG_KGDB_LOW_LEVEL_TRAP=y
+        CONFIG_EARLY_PRINTK=y
+        CONFIG_CC_OPTIMIZE_FOR_SIZE=n
+        EOF
         </pre>
 
-        <p>Enable CONFIG_DEBUG_INFO, CONFIG_DEBUG_INFO_DWARF4
-        and CONFIG_GDB_SCRIPTS in the kernel;</p>
+        <p>Create a tiny config;</p>
 
         <pre>
-        make x86_64_defconfig
-        cat &lt;&lt;EOF &gt;.config-fragment
-        CONFIG_DEBUG_INFO=y
-        CONFIG_DEBUG_KERNEL=y
-        CONFIG_GDB_SCRIPTS=y
-        EOF
-        ./scripts/kconfig/merge_config.sh .config .config-fragment
+        $ make ARCH=x86_64 tinyconfig
         </pre>
 
-        <p>Check or change to your needs the configuration;</p>
+        <p>Merge config  with the following script;</p>
+
+        <pre>
+        $ ./scripts/kconfig/merge_config.sh .config .config-fragment
+        </pre>
+
+        <p>Check or change the configuration according to your needs;</p>
+
         <pre>
         $ make nconfig
         </pre>
@@ -138,7 +190,7 @@
             -ex "file vmlinux" \
             -ex 'set arch i386:x86-64:intel' \
             -ex 'target remote localhost:1234' \
-            -ex 'break start_kernel' \
+            -ex 'hbreak start_kernel' \
             -ex 'continue' \
             -ex 'disconnect' \
             -ex 'set arch i386:x86-64' \
@@ -169,11 +221,28 @@
 	(gdb)
 	</pre>
 
+        <p>lx-symbols allows to debug kernel modules, after starting the vm and loading
+        the module use lx-symbols to load the symbols from all the modules loaded in
+        the kernel.</p>
+
+        <pre>
+        (gdb) apropos lx
+        (gdb) lx-symbols
+        </pre>
+
+        <p>It's useful to set conditional breakpoints or a break point can be trigger
+        by unrelated tasks, example of a break point on do_exit function but only by
+        the process with pid 1;</p>
+
+        <pre>
+        (gdb) br do_exit if $lx_current()->pid == 1
+        </pre>
+
         <a href="index.html">C Index</a>
         <p>
-        This is part of the Tribu System Documentation.
-        Copyright (C) 2020
-        Tribu Team.
+        This is part of the LeetIO System Documentation.
+        Copyright (C) 2021
+        LeetIO Team.
         See the file <a href="../../fdl-1.3-standalone.html">Gnu Free Documentation License</a>
         for copying conditions.</p>