initial implementation of swap

+ Slightly unsure if it should be a syscall, or if assign would be
  enough. Also, which thread should run in a fork/spawn? For now, old
  thread, though this might increase latency. Or add swap flag to these
  calls?

1 files changed, 19 insertions, 9 deletions

diff --git a/arch/riscv64/kernel/proc.c b/arch/riscv64/kernel/proc.c
index f85f597..10f8bfa 100644
--- a/arch/riscv64/kernel/proc.c
+++ b/arch/riscv64/kernel/proc.c
@@ -8,10 +8,13 @@
 
 #include <apos/tcb.h>
 #include <apos/elf.h>
+
+#include <arch/proc.h>
+
 #include "regs.h"
 #include "csr.h"
 
-stat_t run_init(struct tcb *t, void *fdt)
+void run_init(struct tcb *t, void *fdt)
 {
 	/** \todo actually map fdt into the target address space */
 	csr_write(CSR_SSCRATCH, t);
@@ -20,18 +23,27 @@ stat_t run_init(struct tcb *t, void *fdt)
 	__asm__ volatile ("mv a0, %0\n" : : "r" (fdt) : );
 	__asm__ volatile ("sret\n" ::: "memory");
 	/* we should never reach this */
-	return ERR_ADDR;
+	unreachable();
 }
 
-stat_t set_ipc(struct tcb *t, id_t pid, id_t tid)
+void set_args(struct tcb *t, struct sys_ret a)
 {
 	struct riscv_regs *r = (struct riscv_regs *)(--t);
-	r->a2 = (long)pid;
-	r->a3 = (long)tid;
-	return OK;
+	r->a0 = a.s;
+	r->a1 = a.ar0;
+	r->a2 = a.ar1;
+	r->a3 = a.ar2;
+	r->a4 = a.ar3;
+	r->a5 = a.ar4;
 }
 
-stat_t set_thread(struct tcb *t)
+struct sys_ret get_args(struct tcb *t)
+{
+	struct riscv_regs *r = (struct riscv_regs *)(--t);
+	return (struct sys_ret){r->a0, r->a1, r->a2, r->a3, r->a4, r->a5};
+}
+
+void set_thread(struct tcb *t)
 {
 	/* get location of registers in memory */
 	/** \todo check alignment, should be fine but just to be sure */
@@ -40,6 +52,4 @@ stat_t set_thread(struct tcb *t)
 	/* insert important values into register slots */
 	r->sp = (long)t->thread_stack_top;
 	r->tp = (long)t->thread_storage;
-
-	return OK;
 }