Change in coreboot[master]: cbfs: Add helper functions to look up size and type of a file

[Jakub Czapiga (Code Review)]

Attention is currently required from: Julius Werner, Werner Zeh.
Jakub Czapiga has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/59312 )

Change subject: cbfs: Add helper functions to look up size and type of a file
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Patch Set 1:

(3 comments)

File src/include/cbfs.h:

https://review.coreboot.org/c/coreboot/+/59312/comment/ea65afe8_e0a0a501 
PS1, Line 134: static inline bool cbfs_file_exists(const char *name);
             : static inline bool cbfs_ro_file_exists(const char *name);
I wonder, if we actually need these functions. cbfs_load() will return CB_CBFS_NOT_FOUND (or other error code) if file does not exist. Are there real use cases for this function? The only one I can think of is with cbfs_map(), but it also returns NULL if file does not exist.

https://review.coreboot.org/c/coreboot/+/59312/comment/50b07fca_316e6012 
PS1, Line 308: static inline size_t cbfs_get_size(const char *name)
Should not these functions be inaccessible for code running in CAR mode and similar? This might make stack big because of cbfs_mdata, which is pretty big. Do early stages have enough stack memory? Or does GCC/Clang optimize it enough?

File src/lib/cbfs.c:

https://review.coreboot.org/c/coreboot/+/59312/comment/396b322e_9f9351ab 
PS1, Line 528: if ((err = _cbfs_boot_lookup(prog_name(pstage), false, &mdata, &rdev)))
Would not it be cleaner to set err value in a separate line above? Personally I find assign-and-check pattern a anti-pattern.