N900 device tree conversion: how to do first step

Commit Message

Pavel Machek June 9, 2013, 4:47 p.m. UTC

On Sun 2013-06-09 11:24:40, Pali Rohár wrote:
> On Sunday 09 June 2013 03:59:44 Pavel Machek wrote:
> > Hi!
> > 
> > I'd like to convert Nokia N900 to device tree.
> > 
> > Unfortunately, serial port is not easily available (very
> > special cable would be needed, does someone know where to get
> > one?) and I don't have BDI (and very special cable would be
> > needed, too).
> > 
> 
> Hello,
> 
> I used serial port only in qemu for debugging. Maybe you can try
> to play with qemu first. Qemu has good n900 HW support.

Yes, qemu is helpful.

For the record: this is how you use it.

KERNEL=/data/l/linux-n900/zImage_dtb
./qflasher -m rx51 -x ./xloader-qemu.bin -s ./secondary-qemu.bin -k $KERNEL -o n900.img -p k=6072

> sd-empty
./qemu-system-arm -s -M n900 -mtdblock n900.img -sd sd-empty -serial
stdio -clock unix -redir tcp:5555:10.0.2.15:22

...and this patch is needed to make it past rx51_init.

Author: Pavel <[e-mail]>
Date:   Sun Jun 9 18:45:39 2013 +0200

    Comment out errata workaround that breaks qemu.

Comments

Pali Rohár June 9, 2013, 5:03 p.m. UTC | #1

On Sunday 09 June 2013 18:47:45 Pavel Machek wrote:
> On Sun 2013-06-09 11:24:40, Pali Rohár wrote:
> > On Sunday 09 June 2013 03:59:44 Pavel Machek wrote:
> > > Hi!
> > > 
> > > I'd like to convert Nokia N900 to device tree.
> > > 
> > > Unfortunately, serial port is not easily available (very
> > > special cable would be needed, does someone know where to
> > > get one?) and I don't have BDI (and very special cable
> > > would be needed, too).
> > 
> > Hello,
> > 
> > I used serial port only in qemu for debugging. Maybe you can
> > try to play with qemu first. Qemu has good n900 HW support.
> 
> Yes, qemu is helpful.
> 
> For the record: this is how you use it.
> 
> KERNEL=/data/l/linux-n900/zImage_dtb
> ./qflasher -m rx51 -x ./xloader-qemu.bin -s
> ./secondary-qemu.bin -k $KERNEL -o n900.img -p k=6072
> 
> > sd-empty
> 
> ./qemu-system-arm -s -M n900 -mtdblock n900.img -sd sd-empty
> -serial stdio -clock unix -redir tcp:5555:10.0.2.15:22
> 
> ...and this patch is needed to make it past rx51_init.
> 
> Author: Pavel <[e-mail]>
> Date:   Sun Jun 9 18:45:39 2013 +0200
> 
>     Comment out errata workaround that breaks qemu.
> 
> diff --git a/arch/arm/mach-omap2/board-rx51.c
> b/arch/arm/mach-omap2/board-rx51.c index 938e46f..0ffd7d3
> 100644
> --- a/arch/arm/mach-omap2/board-rx51.c
> +++ b/arch/arm/mach-omap2/board-rx51.c
> @@ -108,11 +108,13 @@ static void __init rx51_init(void)
>  	rx51_peripherals_init();
>  	rx51_camera_init();
> 
> +#if 0
>  #ifdef CONFIG_ARM_ERRATA_430973
>  	printk(KERN_INFO "RX-51: Enabling ARM errata 430973
> workaround.\n"); /* set IBE to 1 */
>  	rx51_secure_update_aux_cr(1 << 6, 0);
>  #endif
> +#endif
> 
>  	/* Ensure SDRC pins are mux'd for self-refresh */
>  	omap_mux_init_signal("sdrc_cke0", OMAP_PIN_OUTPUT);

Hm, right qemu not running in omap secure mode, so it can really 
break booting. So before calling secure code it is needed to 
check if we are really on secure device. I think this code help:

if (omap_type() == OMAP2_DEVICE_TYPE_SEC)

Can somebody confirm if above check is correct for OMAP3 HS 
device? And also if it does not pass in qemu?

Patch

diff --git a/arch/arm/mach-omap2/board-rx51.c b/arch/arm/mach-omap2/board-rx51.c
index 938e46f..0ffd7d3 100644
--- a/arch/arm/mach-omap2/board-rx51.c
+++ b/arch/arm/mach-omap2/board-rx51.c
@@ -108,11 +108,13 @@  static void __init rx51_init(void)
 	rx51_peripherals_init();
 	rx51_camera_init();
 
+#if 0
 #ifdef CONFIG_ARM_ERRATA_430973
 	printk(KERN_INFO "RX-51: Enabling ARM errata 430973 workaround.\n");
 	/* set IBE to 1 */
 	rx51_secure_update_aux_cr(1 << 6, 0);
 #endif
+#endif
 
 	/* Ensure SDRC pins are mux'd for self-refresh */
 	omap_mux_init_signal("sdrc_cke0", OMAP_PIN_OUTPUT);