[U-Boot] [PATCH] imx: mx7: Add support for USB boot mode

[Troy Kisky]

On 8/29/2017 7:37 AM, Eric Nelson wrote:
> Hi Troy,
> 
> On 08/28/2017 09:42 AM, Troy Kisky wrote:
>> On 8/27/2017 3:04 PM, Eric Nelson wrote:
>>> This adds support for USB boot mode on the i.MX7D SoC, which
>>> is most useful when doing U-Boot development on this chip.
>>>
>>> i.e., it enables you to enter the ROM boot loader's serial
>>> download protocol using the command:
>>>
>>> => bmode usb
>>>
>>> Signed-off-by: Eric Nelson <eric at nelint.com>
>>> ---
>>>   arch/arm/mach-imx/mx7/soc.c | 2 ++
>>>   1 file changed, 2 insertions(+)
>>>
>>> diff --git a/arch/arm/mach-imx/mx7/soc.c b/arch/arm/mach-imx/mx7/soc.c
>>> index 87bf105..63ee59f 100644
>>> --- a/arch/arm/mach-imx/mx7/soc.c
>>> +++ b/arch/arm/mach-imx/mx7/soc.c
>>> @@ -372,6 +372,8 @@ void set_wdog_reset(struct wdog_regs *wdog)
>>>    * to SBMR1, which will determine the boot device.
>>>    */
>>>   const struct boot_mode soc_boot_modes[] = {
>>
>> You might want to add
>>
>> +       {"normal",      MAKE_CFGVAL(0x00, 0x00, 0x00, 0x00)},
>>
>>
>> while you're at it, to undo with "bmode normal"
>>
> 
> Normal, meaning "don't override"?
> 
> Why would you want to do this?
> 
> Please advise,

Hi Eric!


If you do "bmode usb" and then use "imx_usb" to load a new u-boot.
You may want to do "bmode normal", so that a watchdog reset from
the linux kernel or from u-boot will work as expected, instead of
starting the ROM USB downloader again.

BR

Troy