xref: /OK3568_Linux_fs/u-boot/board/congatec/conga-qeval20-qa3-e3845/README (revision 4882a59341e53eb6f0b4789bf948001014eff981)
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2*4882a593SmuzhiyunU-Boot console UART selection:
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5*4882a593SmuzhiyunThe U-Boot port for this congatec board currently supports two different
6*4882a593Smuzhiyunconfigurations (defconfig files). The only difference is the UART that
7*4882a593Smuzhiyunis used as the U-Boot console UART. The default defconfig file:
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9*4882a593Smuzhiyunconga-qeval20-qa3-e3845_defconfig
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11*4882a593Smuzhiyunprovides this console on the UART0 which is provided via a Winbond
12*4882a593SmuzhiyunSuper-IO chip connected on the congatec Qseven 2.0 evaluation carrier
13*4882a593Smuzhiyunboard (conga-QEVAL). This UART is the one provided with a SubD9
14*4882a593Smuzhiyunconnector on the mainboard (the low one). The 2nd defconfig file:
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16*4882a593Smuzhiyunconga-qeval20-qa3-e3845-internal-uart_defconfig
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18*4882a593Smuzhiyunprovides the U-Boot console on the BayTrail internal legacy UART,
19*4882a593Smuzhiyunwhich is routed from the QSeven SoM to the X300 connector on the
20*4882a593Smuzhiyunbaseboard. Here is called COM2. The baseboard already provides the
21*4882a593SmuzhiyunRS232 level shifters. So a TTL-USB UART adapter does not work in
22*4882a593Smuzhiyunthis case. The signals need to get connected directly to the
23*4882a593SmuzhiyunRS232 level signals of the PC UART via some adapter cable.
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