fix LLVM

+ Anything extern is right out as LLVM doesn't produce correct code for
  them. Maybe if I added some extra attributes but I'm skeptical.
  Replaced with static variables and getters/setters.

+ Inline ASM is apparently a bit buggy, so use an assembly stub when jumping to init.

+ Minimize work done in main() to minimize chance of LLVM doing something silly.
  Still not 100% certain that I shouldn't just write the main() as an assembly stub
  in arch/riscv64 to be absolutely sure everything works as intended.

+ Make .kernel.start section SHF_ALLOC, otherwise lld complains about
  pc-relative addressing

Probably some other stuff as well that I'm forgetting right now. But at least with
LLVM14 LTO seems to work, which is pretty cool?

1 files changed, 3 insertions, 3 deletions

diff --git a/arch/riscv64/kernel/smp.c b/arch/riscv64/kernel/smp.c
index e48a216..425d3ce 100644
--- a/arch/riscv64/kernel/smp.c
+++ b/arch/riscv64/kernel/smp.c
@@ -59,7 +59,7 @@ void smp_bringup(struct vmem *b, void *fdt)
 	extern void riscv_bringup(void);
 
 	/* mark first hart available */
-	cpuid_to_hartid(0) = -1;
+	set_hartid(0, -1);
 
 	/* assume we're in default Sv mode, in the future this will have to be
 	 * fixed if we start implementing Sv48 etc. */
@@ -87,12 +87,12 @@ void smp_bringup(struct vmem *b, void *fdt)
 		if (r.value == SBI_HART_STARTED) {
 			/* there should ever only be one started hart */
 			assert(cpuid_to_hartid(0) == -1);
-			cpuid_to_hartid(0) = hartid;
+			set_hartid(0, hartid);
 			continue;
 		}
 
 		/** @todo should check that cpus doesn't go over MAX_CPUS */
-		cpuid_to_hartid(cpus++) = hartid;
+		set_hartid(cpus++, hartid);
 
 		/** @todo try to remember to free these as well */
 		smp_init_stacks[hartid] = (void *)alloc_page(BASE_PAGE) +