[U-Boot-Users] U-boot reset command on MPC8548CDS
Hi,
I have u-boot 1.1.6 running on my MPC8548CDS board. When trying the u-boot 'reset' command, the board hangs after RAM initialization. Stepping through the code showed, that the board hangs when accessing the DDR RAM during relocation. Accessing RAM isn't also possible with my BDI2000 in that state.
Is this a known issue? Why is the RAM not longer accessible after the 2nd initialization?
Best regards,
Thomas Schafer
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Kontron Modular Computers GmbH
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Tel.: + 49 (0)681 / 95916 - 203 Fax: + 49 (0)681 / 95916 - 100 E-mail: thomas.schaefer@kontron.com
Thomas Schafer wrote:
Hi,
I have u-boot 1.1.6 running on my MPC8548CDS board. When trying the u-boot 'reset' command, the board hangs after RAM initialization. Stepping through the code showed, that the board hangs when accessing the DDR RAM during relocation. Accessing RAM isn't also possible with my BDI2000 in that state.
Is this a known issue? Why is the RAM not longer accessible after the 2nd initialization?
Does this happen with earlier versions of U-Boot? The reason I ask is that the I2C code for 85xx was recently changed (see fsl_i2c.c), and I2C is used to initialize DDR.
On Nov 15, 2006, at 12:14 PM, Thomas Schafer wrote:
Is this a known issue? Why is the RAM not longer accessible after the 2nd initialization?
The software 'reset' in u-boot only causes the e500 core to reset, none of the peripherals nor memory controllers. Whacking the DDR setup again in this state just makes a big mess.
The only proper way to do this is with a board design where you can drive the external reset out of the processor, with external hardware that will then "loop" this back as a hard reset. See HRESET_REQ in the RSTCR. It's a simple patch that I guess I could submit :-) Not all board designs support this, though.
Thanks.
-- Dan
participants (3)
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Dan Malek -
Thomas Schafer -
Timur Tabi