diff options
Diffstat (limited to 'user')
| -rw-r--r-- | user/uthread.c | 33 | ||||
| -rw-r--r-- | user/uthread_switch.S | 30 |
2 files changed, 57 insertions, 6 deletions
diff --git a/user/uthread.c b/user/uthread.c index 18b773d..7641d77 100644 --- a/user/uthread.c +++ b/user/uthread.c @@ -11,9 +11,30 @@ #define MAX_THREAD 4 +// Saved registers for kernel context switches. +struct context { + uint64 ra; + uint64 sp; + + // callee-saved + uint64 s0; + uint64 s1; + uint64 s2; + uint64 s3; + uint64 s4; + uint64 s5; + uint64 s6; + uint64 s7; + uint64 s8; + uint64 s9; + uint64 s10; + uint64 s11; +}; + struct thread { char stack[STACK_SIZE]; /* the thread's stack */ int state; /* FREE, RUNNING, RUNNABLE */ + struct context context; /* saved registers to switch thru threads */ }; struct thread all_thread[MAX_THREAD]; struct thread *current_thread; @@ -56,10 +77,8 @@ thread_schedule(void) next_thread->state = RUNNING; t = current_thread; current_thread = next_thread; - /* YOUR CODE HERE - * Invoke thread_switch to switch from t to next_thread: - * thread_switch(??, ??); - */ + // Invoke thread_switch to switch from t to next_thread: + thread_switch((uint64)&t->context, (uint64)&next_thread->context); } else next_thread = 0; } @@ -73,7 +92,11 @@ thread_create(void (*func)()) if (t->state == FREE) break; } t->state = RUNNABLE; - // YOUR CODE HERE + // Set up new context to start executing at func + memset(&t->context, 0, sizeof(struct context)); + t->context.ra = (uint64)func; + // stack grows downward, set sp at the highest stack address in out thread + t->context.sp = (uint64)t->stack + STACK_SIZE; } void diff --git a/user/uthread_switch.S b/user/uthread_switch.S index 5defb12..19cc400 100644 --- a/user/uthread_switch.S +++ b/user/uthread_switch.S @@ -7,5 +7,33 @@ .globl thread_switch thread_switch: - /* YOUR CODE HERE */ + sd ra, 0(a0) + sd sp, 8(a0) + sd s0, 16(a0) + sd s1, 24(a0) + sd s2, 32(a0) + sd s3, 40(a0) + sd s4, 48(a0) + sd s5, 56(a0) + sd s6, 64(a0) + sd s7, 72(a0) + sd s8, 80(a0) + sd s9, 88(a0) + sd s10, 96(a0) + sd s11, 104(a0) + + ld ra, 0(a1) + ld sp, 8(a1) + ld s0, 16(a1) + ld s1, 24(a1) + ld s2, 32(a1) + ld s3, 40(a1) + ld s4, 48(a1) + ld s5, 56(a1) + ld s6, 64(a1) + ld s7, 72(a1) + ld s8, 80(a1) + ld s9, 88(a1) + ld s10, 96(a1) + ld s11, 104(a1) ret /* return to ra */ |