image.h: isolate android_image_* functions from tooling
On Feb. 16, 2020, Tom reported [1] build failure of U-Boot in-tree
tooling after applying https://patchwork.ozlabs.org/cover/1229663/
("[v6,0/7] rsa: extend rsa_verify() for UEFI secure boot").
Later on, Heinrich stressed the urgency of the issue in
https://patchwork.ozlabs.org/patch/1250858/#2379069:
>>>>>>>>>
We should finalize the topic as it stops EFI patches from being merged
>>>>>>>>>
On the surface, the problem is caused by U-Boot commits [2-3], which
employed 'u32' in 'include/image.h', while historically U-Boot tooling
stayed agnostic on the {u,s}{8,16,32} types.
Thanks to Tom, Yamada-san and Heinrich, the following solutions have
been put head-to-head ('+' pros, '-' cons):
A. Use an equivalent fixed-size type, i.e. s/u32/uint32_t/ in both
android function prototypes (image.h) and definitions (c file):
+ quick and low-line-count
- creates a 'soup' of fixed-sized types in the Android C file
- will confuse contributors
- is going against Linux kernel best practices [4]
B. Guard Android functions by '!defined(USE_HOSTCC)' in image.h:
+ quick and low-line-count
+ reflects the reality (no android function is used by tooling)
+ zero impact on other subsystems
- ifdeffery may look annoying (pre-existing problem of image.h)
C. Make {u8,u16,u32} available in U-Boot tooling:
+ quick and low-line-count
+ [Yamada-san][5]:
* forbidding u32 for tools is questionable to me
* Linux kernel and Barebox use {u8,u16,u32} for the tools space
- breaks U-Boot tradition?
- has larger impact than [A] and [B]
- adds type complexity/inconsistency in the tooling space
D. [Yamada-san] Refactor the headers to minimize the code shared
between U-Boot space and tooling space:
+ probably the long-term solution
- high effort
- can be seen/done as an incremental update on top of [B]
Looking at the above, [B] looks like the natural way to go forward.
[1] https://patchwork.ozlabs.org/patch/1238245/#2363052
[2] commit 7f2531502c74c0 ("image: android: Add routine to get dtbo params")
[3] commit c3bfad825a71ea ("image: android: Add functions for handling dtb field")
[4] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e6176fa4728fb6d
("checkpatch: add --strict warning for c99 fixed size typedefs : int<size>_t")
[5] https://patchwork.ozlabs.org/patch/1238245/#2363340
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Sam Protsenko <joe.skb7@gmail.com>
Cc: Lokesh Vutla <lokeshvutla@ti.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reported-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Tested-by: Heinrich Schuchardt <xpyron.glpk@gmx.de>
1 file changed