Hi Paul, Tom,
i am failing bring up my AM335x boards (tseries, kwb) with bare UART connection since introducing this change.
-- U-Boot SPL 2015.10-rc2-00079-g35f2192-dirty (Aug 25 2015 - 07:34:24) boot device - 0 SPL: Unsupported Boot Device (0)! ### ERROR ### Please RESET the board ### ---
The source of my problem is the __weak function in omap-common/boot-common.c
__weak u32 omap_sys_boot_device(void) { return BOOT_DEVICE_NONE; }
which one is called on line #82
For my understanding this function should be called allways if chip has basically support for some BOOT_DEVICE_x __AND__ there is no implementation for it - the function should prevent target from stalling with selecting another (hopefully working) boot-device. Right ?
I am not sure at this time how to deal with the facts ... i see several possibilities:
a) i have to implement some "omap_sys_boot_device" function in my boards - this would maybe sometimes comfortable but i think this is not inventors mind. It would be more convenient to implement it in some common place for AM335x or OMAP. But what do with the information about SYS_BOOT pins ? they always represent a boot-order ... which boot-device should it take ?
b) and/or something is wrong with the #ifdef ... construct at line #67 - In fact there is a problem with / defined(BOOT_DEVICE_USBETH) && !defined(CONFIG_SPL_USBETH_SUPPORT)/
basicaly BOOT_DEVICE_USBETH is defined in spl.h but in my configuration there is no #define for CONFIG_SPL_USBETH_SUPPORT and so the following switch/case calls in case of BOOT_DEVICE_UART this weak function.
further i think that this construct isn't complete yet, because it wants to handle all peripheral booting on AM335x or OMAP in general.
following peripherals are currently handled:
BOOT_DEVICE_UART BOOT_DEVICE_USB BOOT_DEVICE_USBETH
but there is also BOOT_DEVICE_CPGMAC
Summary i think this changeset isn't complete.
How we want to deal with this facts ?
best regards, Hannes
On 28.07.2015 16:59, Tom Rini wrote:
On Wed, Jul 15, 2015 at 04:02:23PM +0200, Paul Kocialkowski wrote:
OMAP devices might boot from peripheral devices, such as UART or USB. When that happens, the U-Boot SPL tries to boot the next stage (complete U-Boot) from that peripheral device, but in most cases, this is not a valid boot device.
This introduces a fallback option that reads the SYS_BOOT pins, that are used by the bootrom to determine which device to boot from. It is intended for the SYS_BOOT value to be interpreted in the memory-preferred scheme, so that the U-Boot SPL can load the next stage from a valid location.
Practically, this options allows loading the U-Boot SPL through USB and have it load the next stage according to the memory device selected by SYS_BOOT instead of stalling.
Signed-off-by: Paul Kocialkowski contact@paulk.fr
Applied to u-boot/master, thanks!
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