xref: /openbmc/u-boot/board/congatec/conga-qeval20-qa3-e3845/README (revision 5ebd27d860ec0c6e36f1b0f973653fe66a7360be)
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2*df233e73SStefan RoeseU-Boot console UART selection:
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5*df233e73SStefan RoeseThe U-Boot port for this congatec board currently supports two different
6*df233e73SStefan Roeseconfigurations (defconfig files). The only difference is the UART that
7*df233e73SStefan Roeseis used as the U-Boot console UART. The default defconfig file:
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9*df233e73SStefan Roeseconga-qeval20-qa3-e3845_defconfig
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11*df233e73SStefan Roeseprovides this console on the UART0 which is provided via a Winbond
12*df233e73SStefan RoeseSuper-IO chip connected on the congatec Qseven 2.0 evaluation carrier
13*df233e73SStefan Roeseboard (conga-QEVAL). This UART is the one provided with a SubD9
14*df233e73SStefan Roeseconnector on the mainboard (the low one). The 2nd defconfig file:
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16*df233e73SStefan Roeseconga-qeval20-qa3-e3845-internal-uart_defconfig
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18*df233e73SStefan Roeseprovides the U-Boot console on the BayTrail internal legacy UART,
19*df233e73SStefan Roesewhich is routed from the QSeven SoM to the X300 connector on the
20*df233e73SStefan Roesebaseboard. Here is called COM2. The baseboard already provides the
21*df233e73SStefan RoeseRS232 level shifters. So a TTL-USB UART adapter does not work in
22*df233e73SStefan Roesethis case. The signals need to get connected directly to the
23*df233e73SStefan RoeseRS232 level signals of the PC UART via some adapter cable.
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