[coreboot-gerrit] [S] Change in coreboot[main]: payloads/external/iPXE: introduce support for named configurations

[Krystian Hebel (Code Review)]

Attention is currently required from: Felix Singer, Filip Lewiński, Martin L Roth, Michał Kopeć.

Krystian Hebel has posted comments on this change by Filip Lewiński. ( https://review.coreboot.org/c/coreboot/+/82041?usp=email )

Change subject: payloads/external/iPXE: introduce support for named configurations
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Patch Set 9:

(1 comment)

File payloads/external/iPXE/Makefile:

https://review.coreboot.org/c/coreboot/+/82041/comment/b59f0495_c793a836?usp... :
PS9, Line 55: config: checkout apply_named_config
This is different from what I had in mind, and it doesn't solve the original problem of modified files in git directory if `make build` fails.

I was thinking about using named config unconditionally (i.e. no Kconfig option), and, in this `make` target, creating files in the directory of named config, with possible `#undef`s if needed. For example, for serial (I hope I haven't made any typos):

```
    cp "$(project_dir)/src/config/local/"*.h "$(NAMED_CONFIG_SRC_DIR)/"
ifeq ($(CONSOLE_SERIAL),yy)
    echo "#define CONSOLE_SERIAL" >> "$(NAMED_CONFIG_SRC_DIR)/console.h"
    echo "#undef COMCONSOLE" >> "$(NAMED_CONFIG_SRC_DIR)/serial.h"
    echo "#define COMCONSOLE $(IPXE_UART)" >> "$(NAMED_CONFIG_SRC_DIR)/serial.h"
    echo "#undef COMSPEED" >> "$(NAMED_CONFIG_SRC_DIR)/serial.h"
    echo "#define COMSPEED $(CONFIG_TTYS0_BAUD)" >> "$(NAMED_CONFIG_SRC_DIR)/serial.h"
endif
```

Similarly for remaining options below.