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, 12 insertions, 1 deletions

diff --git a/arch/riscv64/kernel/arch.c b/arch/riscv64/kernel/arch.c
index 4561d8b..5dc50cf 100644
--- a/arch/riscv64/kernel/arch.c
+++ b/arch/riscv64/kernel/arch.c
@@ -13,7 +13,18 @@
 #include "csr.h"
 #include "arch.h"
 
-id_t __cpuid_to_hartid[MAX_CPUS];
+/** Array where indexing is done with CPU IDs, giving the corresponding hart ID. */
+static id_t __cpuid_to_hartid[MAX_CPUS];
+
+id_t cpuid_to_hartid(id_t cpu)
+{
+	return __cpuid_to_hartid[cpu];
+}
+
+void set_hartid(id_t cpu, id_t hartid)
+{
+	__cpuid_to_hartid[cpu] = hartid;
+}
 
 id_t hartid_to_cpuid(id_t hart)
 {