add basic SMP support, just jumping to smp_start

arch/aarch64/kernel/entry.S

@@ -209,7 +209,16 @@ mmu_on:
   /* Test core ID */
   mrs x0, mpidr_el1
 
+  ldr x0, =cpu_online
+  ldr x0, [x0]
+  cmp x0, 0
+  b.ne smp_start
+
   bl hermit_main
+  bl halt
+
+smp:
+  bl smp_main
 
   /* halt */
 halt:
@@ -273,6 +282,11 @@ _setup_cpu:
     ret
 
 _setup_pgtable:
+    ldr     x0, =cpu_online
+    ldr     x0, [x0]
+    cmp     x0, 0
+    b.ne    4f
+
     ldr     x0, =kernel_end
     /* align to a 16KByte boundary */
     add     x0, x0, 0x10000
@@ -320,6 +334,7 @@ _setup_pgtable:
     cmp     x7, 511*PAGE_SIZE
     b.lo    3b
 
+4:
     ret
 
 //_calc_offset:

arch/aarch64/kernel/tasks.c

@@ -37,6 +37,8 @@
 #define TSL_ALIGNMASK		((~0L) << TLS_ALIGNBITS)
 #define TLS_FLOOR(addr)		((((size_t)addr) + TLS_ALIGNSIZE - 1) & TSL_ALIGNMASK)
 
+extern int smp_main(void);
+
 /*
  * Note that linker symbols are not variables, they have no memory allocated for
  * maintaining a value, rather their address is their value.
@@ -45,6 +47,7 @@ extern const void tls_start;
 extern const void tls_end;
 
 extern atomic_int32_t cpu_online;
+extern atomic_int32_t current_boot_id;
 
 static char tls[16][DEFAULT_STACK_SIZE];
 static int id = 0;
@@ -167,6 +170,19 @@ int create_default_frame(task_t* task, entry_point_t ep, void* arg, uint32_t cor
 	return 0;
 }
 
+#if MAX_CORES > 1
+int smp_start(void)
+{
+	int32_t core_id = atomic_int32_read(&current_boot_id);
+
+	LOG_INFO("Try to initialize processor (local id %d)\n", core_id);
+
+	atomic_int32_inc(&cpu_online);
+
+	return smp_main();
+}
+#endif
+
 int is_proxy(void)
 {
 	return 0;

arch/aarch64/kernel/timer.c

@@ -175,6 +175,9 @@ int timer_wait(unsigned int ticks)
 int timer_init(void)
 {
 #ifdef DYNAMIC_TICKS
+	if (boot_tsc)
+		return 0;
+
 	boot_tsc = get_cntpct();
 	set_per_core(last_tsc, boot_tsc);
 #endif