Message ID | 566592F4.4090901@nelint.com |
---|---|
State | Not Applicable |
Delegated to: | Stefano Babic |
Headers | show |
Hi Eric, On 07/12/2015 15:08, Eric Nelson wrote: >> I agree with you, in fact it does not work - but I do not see a way to >> inform the ROM that next time it should run with USB as boot device. >> From the fusemap, I tried to set BOOT_CFG4 as 0x40 ("Reserved for serial >> ROM"), and fixing BOOT_CFG1 to 0x30, but it was only a try. In fact, we >> need to change BMODE from internal to serial, and I do not see a way in >> the "official" documentation. >> > > It doesn't help that all of this is undocumented :), but reverse- > engineering the bmode command :-) > > The "bmode usb" command sets gpr9 to 1, which isn't used for anything > else, so something like this will work: > > diff --git a/arch/arm/imx-common/spl.c b/arch/arm/imx-common/spl.c > index 28217d2..54f22e6 100644 > --- a/arch/arm/imx-common/spl.c > +++ b/arch/arm/imx-common/spl.c > @@ -26,8 +26,10 @@ u32 spl_boot_device(void) > * Check for BMODE if serial downloader is enabled > * BOOT_MODE - see IMX6DQRM Table 8-1 > */ > - if ((bmode >> 24) == 0x01) /* Serial Downloader */ > + if (((bmode >> 24) == 0x01) /* Serial Downloader */ > + || (gpr10_boot && (1 == reg))) > return BOOT_DEVICE_UART; > > AFAIK, there isn't any other way to get a value of 1 into GPR9, > so the test is safe. > This is a nice trick - I cannot see as well any combination for obtaining a 0x01 in GPR9. > Secondarily, since the low four bits are discarded in the switch(), > this prevents an almost-always-wrong interpretation of 1 as > OneNAND/NOR (I think there are very few if any i.MX6 boards using > OneNAND or NOR for boot). Agree. I add your proposal in V2, thanks ! Best regards, Stefano
diff --git a/arch/arm/imx-common/spl.c b/arch/arm/imx-common/spl.c index 28217d2..54f22e6 100644 --- a/arch/arm/imx-common/spl.c +++ b/arch/arm/imx-common/spl.c @@ -26,8 +26,10 @@ u32 spl_boot_device(void) * Check for BMODE if serial downloader is enabled * BOOT_MODE - see IMX6DQRM Table 8-1 */ - if ((bmode >> 24) == 0x01) /* Serial Downloader */ + if (((bmode >> 24) == 0x01) /* Serial Downloader */ + || (gpr10_boot && (1 == reg))) return BOOT_DEVICE_UART; AFAIK, there isn't any other way to get a value of 1 into GPR9, so the test is safe.