Just out of curiosity, i tried make BOARD=pico2. The build fails with:
So one of the items that will need changing is the real time clock. I don't know what else might fail.
Whereas for a BOARD=pico2 compilation it gives:
So the pico2 code knows that it can do unaligned access, but the optimiser is not smart enough to eliminate the test for an aligned pointer.
Code:
[ 5%] Building C object CMakeFiles/bbcbasic.dir/home/pi/pico/PicoBB/src/bbpico.c.obj/home/pi/pico/PicoBB/src/bbpico.c:180:10: fatal error: hardware/rtc.h: No such file or directory #include <hardware/rtc.h> ^~~~~~~~~~~~~~~~compilation terminated.make[2]: *** [CMakeFiles/bbcbasic.dir/build.make:113: CMakeFiles/bbcbasic.dir/home/pi/pico/PicoBB/src/bbpico.c.obj] Error 1Doing an objdump -S on bbeval.c.obj gives, for a BOARD=pico compilation:Whether it does or not will depend on how GCC handles this when targetting the Pico 2:Hopefully on the Pico 2 (unaligned_int*)p and (int*)p will be identical, the compiler will realise that the conditional test is therefore doing nothing, and the whole thing will be simplified as *((int*)p). But ideally this should be checked.Code:
typedef __attribute__((aligned(1))) int unaligned_int;static inline int ILOAD(void* p){ return (intptr_t)p&3 ? *((unaligned_int*)p) : *((int*)p); }
It will certainly be very important that GCC is passed the correct switches so that it knows not to emit code to handle unaligned memory accesses, if this is now unnecessary.
Code:
// Helper macros to fix alignment problem:#ifdef PICOstatic inline int ILOAD(void* p){ return (intptr_t)p&3 ? *((unaligned_int*)p) : *((int*)p); } 38:078b lslsr3, r1, #30 3a:d00d beq.n58 <loadn+0x58> 3c:780b ldrbr3, [r1, #0] 3e:784a ldrbr2, [r1, #1] 40:0212 lslsr2, r2, #8 42:431a orrsr2, r3 44:788b ldrbr3, [r1, #2] 46:041b lslsr3, r3, #16 48:431a orrsr2, r3 4a:78cb ldrbr3, [r1, #3] 4c:061b lslsr3, r3, #24 4e:4313 orrsr3, r2v.i.n = ILOAD(ptr) ; 50:9300 strr3, [sp, #0] 52:17db asrsr3, r3, #31 54:9301 strr3, [sp, #4]Code:
// Helper macros to fix alignment problem:#ifdef PICOstatic inline int ILOAD(void* p){ return (intptr_t)p&3 ? *((unaligned_int*)p) : *((int*)p); } 5e:f013 0f03 tst.wr3, #3 62:bf14 itene 64:681a ldrner2, [r3, #0] 66:681a ldreqr2, [r3, #0]v.i.n = ILOAD(ptr) ; 68:17d3 asrsr3, r2, #31 6a:e9cd 2300 strdr2, r3, [sp]Statistics: Posted by Memotech Bill — Mon Aug 19, 2024 7:11 pm