RFC: Device Tree support #679
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Prepare Device Tree support (CFG_DT=y). Import libfdt code from https://git.kernel.org/cgit/utils/dtc/dtc.git commit 53bf130b1cdd ("libfdt: simplify fdt_node_check_compatible()"). Some build flags are removed as needed to build a few source files. The '-pedantic' flag, however, is removed for the whole TEE core because it causes errors in <libfdt.h> which may be included from anywhere. Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
When CFG_DT=y, OP-TEE expects to find the address of the Flattened Device Tree (FDT) binary in r2. The bootloader has to take care of this. r2 is not used when CFG_DT=n. Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
When CFG_DT=y a linker section is created (.rodata.dtdrv) to hold all the DT-compatible drivers. The table can later be queried at runtime. Some manipulation functions are exported in <kernel/dt.h>. Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Add a common interface for UART drivers. Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
When CFG_DT=y, look for console UART parameters from DT properties: /chosen/secure-stdout-path and /chosen/stdout-path. Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
The PL011 driver is extended to register a struct serial_driver interface through the dt_driver struct when CFG_DT=y. Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
When DT is enabled, memory has to be reserved for the console code to be able to configure any UART because console_init() has no way to do dynamically currently. Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
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Over all this looks good, definitely the right direction. What's next step, a full review? |
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@jenswi-linaro I'd like to get some feedback at Linaro Connect next week. Also if possible involve the ARM-TF maintainers and see what they think, bearing in mind that some ARM-TF patches depend on things that are not 100% upstream (OP-TEE dispatcher and HiKey support). |
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Overall looks good to me too. |
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Replaced by #1388. |
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This is a proof-of-concept showing how OP-TEE can get information from the Device Tree to configure its console, i.e.,
/chosen/secure-stdout-pathor/chosen/stdout-path.Tested on HiKey. Build with
make PLATFORM=hikey CFG_TEE_CORE_LOG_LEVEL=3 CFG_DT=y.Depends on https://github.com/jforissier/arm-trusted-firmware/tree/dt.