Linux Kernel 4.9.y
From IGEP - ISEE Wiki
Introduction
This article is for specific 2.6.37.y Linux kernel branch series. All the steps has been tested with Ubuntu 12.04 64b and IGEP SDK Yocto Toolchain 1.2.2-3.
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Para dar soporte a una nueva board basada en imx en el kernel es necesario tener un fichero de configuracion defconfig (.config) y una dtb.
Por defecto empezaremos con un defconfig ya creado por igep para procesadores imx
Para que el kernel compile la dtb es necesario tener una dts con la configuración de los periféricos y los drivers que los gestionan,ademas de una anidación al dtsi del procesador correspondiente ( en este caso imx6 ya sea quad, dual, solo ...)
En el caso de igep con procesadores imx
DUAL
imx6dl-igep-base0040ra1.dts
imx6dl-igep-base0040rc2.dts
imx6dl-igep-base0040rd102.dts
QUAD
imx6q-igep-base0040ra1.dts
imx6q-igep-base0040rc2.dts
imx6q-igep-base0040rd102.dts
GENERICA
imx6qdl-igep-base0040ra.dtsi
imx6qdl-igep-base0040rb.dtsi
imx6qdl-igep-igep0046ra.dtsi
imx6qdl-igep-igep0046rc.dtsi
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Las DTS están anidadas, esto quiere decir que se cogerá la dtb generada a partir de la .dts dependiendo del procesador que monte igep en este caso.
Para que el kernel compile las .dts en dtb se ha de añadir en el Makefile de arch/arm/boot/dts/
(dentro de dtb-$(CONFIG_SOC_IMX6Q) += \)
imx6dl-igep-base0040rc2.dtb \
imx6dl-igep-base0040rd102.dtb \
imx6q-igep-base0040rc2.dtb \
imx6q-igep-base0040rd102.dtb \
|
Setup IGEP SDK Yocto Toolchain 1.2.2-3
Install
Download - isee.biz
follow the next steps:
- Open a terminal
- Located your downloaded file, in my case is inside /home/jdoe/Downloads:
<span style="color: #000000;">jdoe@ubuntu ~ $ cd Downloads/</span>
- Extract binaries in root directory with root privileges
<span style="color: #000000;">jdoe@ubuntu ~/Downloads $ sudo tar jxf igep-sdk-yocto-toolchain-*.tar.bz2 -C /</span>
- Make sure that binaries are installed correctly.
<span style="color: #808080;"><span style="color: #000000;">jdoe@ubuntu ~/Downloads $ ls /opt/poky/
1.2 1.2.1</span> </span>
Configure
Open a terminal and type:
<span style="color: #000000;"> export PATH=/opt/poky/1.2/sysroots/i686-pokysdk-linux/usr/bin/armv7a-vfp-neon-poky-linux-gnueabi:$PATH </span>
Compiled binaries
Binaries: latest stable kernel version IGEP OMAP3 devices is: 2.6.37-12 (20161206)
Build kernel from sources
Download the latest stable version sources and follow next steps:
<span style="color: #808080;">wget <a class="external free" href="http://downloads.isee.biz/pub/releases/linux_kernel/v2.6.37-12/linux-omap-2.6.37-12.tar.gz" target="_blank" rel="nofollow noreferrer noopener">http://downloads.isee.biz/pub/releases/linux_kernel/v2.6.37-12/linux-omap-2.6.37-12.tar.gz</a>
tar xzf linux-omap-2.6.37-12.tar.gz
cd linux-omap-2.6.37-12
</span>
Also, it could download from GIT Repositories (http://git.isee.biz/) and test the last unstable version at your own risk (see "Linux mainline tree (development)" chapter in [index.php/The_Linux_kernel The Linux kernel])
Important procedures
- Remove rootfs modules binaries from any previous Kernel
- If you switch to another configuration, clean kernel sources with command: make mrproper
<span style="color: #000000;">Para compilar el kernel se ha de seguir los siguientes pasos:</span>
1- Descargar la rama correspondiente con git
2- Configurar el kernel con la minima configuracion que nos ofrece
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- imx6_igep0046_defconfi
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3- Ejecutar el menuconfig para optimizar la configuracion a traves del menú.
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- menuconfig
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Guardar la configuracion del menuconfig en .config
4- Compilar la imagen los modulos y las dtb
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- zImage modules dtbs
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5- Instalar en el rootfs los modulos del kernel que son cargables ( es decir que no estan built-in)
sudo make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- modules_install INSTALL_MOD_PATH=/opt/nfs-server/rootfs/ubuntu-xenial-armhf-base
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Nota: Es muy importante que el INSTALL_MOD_PATH sea el correcto y de lugar justo al contenido que se esperaría en un sistema linux (usr, bin, etc, home, opt), este comando ademas se ha de ejecutar con sudo.
Si éste comando falla, es muy probable que instale los modulos en el Host PC pudiendo dejar inservible el actual SO.
Scenarios
Consider the following situations:
Scenario A. You have and IGEP0020 board plus IGEP0022 expansion board, then you should add in your [index.php/How_do_I_edit_my_kernel_command_line kernel command line]
<span style="color: #000000;">buddy=igep0022
</span>
Optionally, to enable the IGEP0022 modem which is disabled by default you should add in your [index.php/How_do_I_edit_my_kernel_command_line kernel command line]
<span style="color: #000000;">buddy=igep0022 buddy.modem=yes
</span>
NOTE: UART2 can be used for bluetooth OR modem in expansion board but NOT at same time. They are INCOMPATIBLE.
Scenario B. You have and IGEP0030 board plus BASE0010 expansion board, then you should add in your [index.php/How_do_I_edit_my_kernel_command_line kernel command line]
<span style="color: #000000;">buddy=base0010
</span>
Scenario C. You have and IGEP0030 board plus BASE0010 Rev. B expansion board, then you should add in your [index.php/How_do_I_edit_my_kernel_command_line kernel command line]
<span style="color: #000000;">buddy=base0010 buddy.revision=B
</span>
Scenario D. You have and IGEP0032 board plus BASE0010 Rev. B expansion board, then you should add in your [index.php/How_do_I_edit_my_kernel_command_line kernel command line]
<span style="color: #000000;">buddy=base0010 buddy.revision=B
</span>
Scenario E. You have and IGEP0030 board plus ILMS0015 expansion board, then you should add in your [index.php/How_do_I_edit_my_kernel_command_line kernel command line]
<span style="color: #000000;">buddy=ilms0015
</span>
Layout
Machine specific files are located in arch/arm/mach-omap2/ directory with name board-igep*.c :
- board-igep0020.c: For IGEP0020 machine
- board-igep0030.c: For IGEP0030 machine
- board-igep0032.c: For IGEP0032 machine
Expansion board files, also are located in arch/arm/mach-omap2/ directory with name exp-*.c :
- exp-igep0022.c: For IGEP0022 expansion board
- exp-base0010.c: For BASE0010 expansion board
- exp-ilms0015.c: For ILMS0015 expansion board
Adding New Expansion Boards
This chapter is meant to be a starting point for people to learn how to add your own expansion board in three steps.
Step 1: Add new expansion board file
As you can see in Layout chapter, an expansion board is called exp-.c and should be located in arch/arm/mach-omap2 directory, so the first step will be add a new file for your new expansion board. Following example creates a new expansion board file called exp-dummy.c (arch/arm/mach-omap2/exp-dummy.c)
<span style="color: #808080;"> #include <linux/kernel.h>
#include <linux/init.h>
void __init dummy_init(void)
{
pr_info("Initializing expansion board ... \n");
}
</span>
next, add the new file to be built
<span style="color: #808080;">diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
index 7505be9..a6572f2 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -156,6 +156,7 @@ obj-$(CONFIG_MACH_IGEP0020) += board-igep0020.o \
obj-$(CONFIG_MACH_IGEP0030) += board-igep0030.o \
board-igep00x0.o \
exp-base0010.o \
+ exp-dummy.o \
hsmmc.o
obj-$(CONFIG_MACH_OMAP3_TOUCHBOOK) += board-omap3touchbook.o \
hsmmc.o
</span>
Step 2: Register new expansion board
Now, edit board-igep00x0.h and add an identifier for the new expansion board, for example,
<span style="color: #808080;">diff --git a/arch/arm/mach-omap2/board-igep00x0.h b/arch/arm/mach-omap2/board-igep00x0.h
index 6b9b677..a2325d7 100644
--- a/arch/arm/mach-omap2/board-igep00x0.h
+++ b/arch/arm/mach-omap2/board-igep00x0.h
@@ -15,6 +15,7 @@
#define IGEP00X0_BUDDY_NONE 0x01
#define IGEP00X0_BUDDY_IGEP0022 0x01
#define IGEP00X0_BUDDY_BASE0010 0x02
+#define IGEP00X0_BUDDY_DUMMY 0x03
#define IGEP00X0_BUDDY_HWREV_A (1 << 0)
#define IGEP00X0_BUDDY_HWREV_B (1 << 1)
</span>
also, edit in board-igep00x0.c the buddy_early_param to add the new expansion board,
<span style="color: #808080;">diff --git a/arch/arm/mach-omap2/board-igep00x0.c b/arch/arm/mach-omap2/board-igep00x0.c
index 2a2d8eb..f2b5b27 100644
--- a/arch/arm/mach-omap2/board-igep00x0.c
+++ b/arch/arm/mach-omap2/board-igep00x0.c
@@ -192,6 +192,9 @@ static int __init buddy_early_param(char *str)
if (!strcmp(name, "base0010")) {
igep00x0_buddy_pdata.model = IGEP00X0_BUDDY_BASE0010;
pr_info("IGEP: IGEP0030 machine + BASE0010 (buddy)\n");
+ } else if (!strcmp(name, "dummy")) {
+ igep00x0_buddy_pdata.model = IGEP00X0_BUDDY_DUMMY;
+ pr_info("IGEP: IGEP0030 machine + DUMMY (buddy)\n");
} else
pr_err("IGEP: Unknown buddy for IGEP0030 machine\n");
}
</span>
Step 3: Run expansion board initialization
Finally, modify the machine file and add support for the new expansion board, for example:
<span style="color: #808080;">diff --git a/arch/arm/mach-omap2/board-igep0030.c b/arch/arm/mach-omap2/board-igep0030.c
index 2b97257..44b319d 100644
--- a/arch/arm/mach-omap2/board-igep0030.c
+++ b/arch/arm/mach-omap2/board-igep0030.c
@@ -204,6 +204,8 @@ static struct omap_board_mux board_mux[] __initdata = {
/* Expansion board: BASE0010 */
extern void __init base0010_init(struct twl4030_platform_data *pdata);
+/* Expansion board: DUMMY */
+extern void __init dummy_init(void);
static void __init igep0030_init(void)
{
@@ -223,6 +225,10 @@ static void __init igep0030_init(void)
/* - BASE0010 (adds twl4030_pdata) */
if (igep00x0_buddy_pdata.model == IGEP00X0_BUDDY_BASE0010)
base0010_init(&twl4030_pdata);
+ /* - DUMMY */
+ if (igep00x0_buddy_pdata.model == IGEP00X0_BUDDY_DUMMY)
+ dummy_init();
+
/* Add twl4030 common data */
omap3_pmic_get_config(&twl4030_pdata, TWL_COMMON_PDATA_USB |
</span>
Known issues
See http://processors.wiki.ti.com/index.php/AM35x-OMAP35x-PSP_04.02.00.07_Release_Notes#Known_Issues_-_AM.2FDM37x
modules are not installed correctly
Try to change rootfs owner from root to your username.
<span style="color: #808080;"> sudo chown -R /media/rootfs</span>
wlcore: Unknown symbol
Probably, you didn't erase old module binaries from rootfs. Open IGEP terminal and type:
<span style="color: #808080;">depmod -a
depmod -A </span>
Finally reboot the system
