From 95a05dcc6df30945723056e0110b3ce686f0a1b3 Mon Sep 17 00:00:00 2001
From: Luca Valente <luca.valente2@unibo.it>
Date: Thu, 23 Mar 2023 22:52:21 +0100
Subject: [PATCH] Clean-up `crt0.S`

---
 kernel/cluster.c |  9 +--------
 kernel/crt0.S    | 44 +++++++++++++++++---------------------------
 kernel/init.c    |  1 +
 3 files changed, 19 insertions(+), 35 deletions(-)

diff --git a/kernel/cluster.c b/kernel/cluster.c
index 94040fa..9c9072e 100644
--- a/kernel/cluster.c
+++ b/kernel/cluster.c
@@ -45,18 +45,12 @@ static void cluster_core_init()
     eu_bar_setup(eu_bar_addr(0), (1<<ARCHI_CLUSTER_NB_PE) - 1);
 }
 
+
 void cluster_entry_stub()
 {
     cluster_core_init();
 
-    #ifdef ARCHI_NO_FC
     synch_barrier();
-
-    if(hal_core_id()==0)
-      cluster_start(hal_cluster_id(), main);
-
-    synch_barrier();
-    #endif
     
     int retval = ((int (*)())cluster_entry)();
 
@@ -69,7 +63,6 @@ void cluster_entry_stub()
         cluster_retval = retval;
         cluster_running = 0;
         #ifdef ARCHI_NO_FC
-        pos_init_stop();
         exit(cluster_retval);
         #endif
     }
diff --git a/kernel/crt0.S b/kernel/crt0.S
index 135b526..08aa06f 100644
--- a/kernel/crt0.S
+++ b/kernel/crt0.S
@@ -27,9 +27,11 @@ pos_init_entry:
     csrr    a0, 0xF14
     andi    a1, a0, 0x1f
 #ifdef ARCHI_NO_FC
-    # PEs from 1 to 7 will go to cluster_entry_stub. PE0 will reach them
+    # PEs from 1 to 7 will go to cluster_first_setup. PE0 will reach them
     # later after the pos_init_start
-    bnez    a0, cluster_entry_stub 
+    li t0, 0x10080000
+    sw x0, 0(t0)
+    bnez    a0,  sync_loop
 #else   
     srli    a0, a0, 5
 #ifdef ARCHI_CL_BOOT
@@ -47,18 +49,11 @@ pos_init_entry:
     bnez    a1, pe_start
 #endif
 #endif
-#endif
+  
 #endif
 
-
-#ifdef ARCHI_NO_FC
-    srli    a0, a0, 5  
-    li  x2, 0x10200000
-    li  x3, 0x1
-    la  x4, _start
-    sw  x4, 0x40(x2)
-    sw  x3, 8(x2)
 #endif
+
     # Clear the bss segment
     la      t0, _bss_start
     la      t1, _bss_end
@@ -70,16 +65,18 @@ pos_init_entry:
 
 
     # Stack initialization
-#ifndef ARCHI_NO_FC
     la   x2, stack
-#endif
-
 
     /* Do all other initializations from C code */
     jal  x1, pos_init_start
 
 #ifdef ARCHI_NO_FC
-    j cluster_entry_stub
+    csrr    a0, 0xF14
+    andi    a1, a0, 0x1f
+    li t0, 0x10080000
+    li t1, 0x1
+    sw t1, 0(t0)  
+    j pe_start
 #endif
 
 .section .text
@@ -149,11 +146,7 @@ pos_init_entry:
     .org 0x80
     .global _start
 _start:
-#ifdef ARCHI_NO_FC
-    jal x0, pe_start
-#else
     jal x0, pos_init_entry
-#endif
   
 pos_illegal_instr:
     j __rt_handle_illegal_instr
@@ -171,21 +164,13 @@ pos_semihosting_call:
 
 #if defined(ARCHI_HAS_CLUSTER)
 pe_start:
-#if defined(ARCHI_NO_FC)
-    csrr    a0, 0xF14
-    andi    a1, a0, 0x1f
-#endif
     la   x2, cluster_stacks
     lw   x2, 0(x2)
     li   x3, CLUSTER_STACK_SIZE
     addi a1, a1, 1
     mul  x1, x3, a1
     add  x2, x2, x1
-#if defined(ARCHI_NO_FC)
-    j    pos_init_entry 
-#else
     j    cluster_entry_stub 
-#endif 
 #endif
   
 do_cl_boot:
@@ -202,3 +187,8 @@ loop:
     sw x0, 0(x2)
     wfi
     j loop
+  
+sync_loop:
+    lw t1, 0(t0)
+    bnez    t1,  pe_start
+    j sync_loop
diff --git a/kernel/init.c b/kernel/init.c
index 2c4d083..eb37908 100644
--- a/kernel/init.c
+++ b/kernel/init.c
@@ -87,6 +87,7 @@ void pos_init_start()
   hal_irq_enable();
 
   #ifdef ARCHI_NO_FC
+  cluster_start(hal_cluster_id(), main);
   }
   #else
   if (!hal_is_fc())