Special yield() variant for thunk'ed functions

[mcspr]

cont_suspend() wants stack pointer to be within cont.stack[] and panic()s otherwise esp8266/Arduino#9170 (comment)

stack_thunk_yield() func then gets added from the Core side, which should do 'SP store -> can_yield && yield() -> SP restore' with known stack thunk values esp8266/Arduino@master...mcspr:esp8266-Arduino:bssl/9170-thunk
(maybe with less inline asm though)

[mcspr]

ping @earlephilhower

[earlephilhower]

Sorry, @mcspr . I must have missed this. I'll build on the rp2040 and then merge this morning my time.

[earlephilhower]

Are you going to rebuild the 8266 library, or do you want me to do it?

[mcspr]

Are you going to rebuild the 8266 library, or do you want me to do it?

Will build some time later w/ github actions builder, not a problem

[mcspr]

Will build some time later w/ github actions builder, not a problem

Just to verify... Looking at README, build instructions are make CONF=esp8266 & cp esp8266/libbearssl.a to tools/sdk/lib/ with xtensa toolchain in $PATH. Build works, I see the lib file actually changed

https://github.com/mcspr/esp8266-Arduino/blob/bearssl/build-2024_08_09T13_04_00_00/tools/sdk/lib/libbearssl.a

Why there are extra symbols, though? Something wrong with the config or its safe to ignore?

~/.p/p/f/t/s/lib (master) [0|1]> nm -C libbearssl.a | grep br_ec_c25519
         U br_ec_c25519_m15
00000000 R br_ec_c25519_i15
00000000 R br_ec_c25519_m15
~/.p/p/f/t/s/lib (master)> nm -C libbearssl2.a | grep br_ec_c25519
         U br_ec_c25519_m15
         U br_ec_c25519_m31
00000000 R br_ec_c25519_i15
00000000 R br_ec_c25519_i31
00000000 R br_ec_c25519_m15
00000000 R br_ec_c25519_m31
00000000 T br_ec_c25519_m62_get
00000000 T br_ec_c25519_m64_get

And some extra symbols with i31, m31, m62, m64 in names

[mcspr]

Ah, damn. I see tools/sdk/ssl/Makefile now. nvm then :)