cpu/vexriscv_smp: move smp_slave to crt0. Fixes bare metal demo compilation with VexRiscv-SMP.

litex/soc/cores/cpu/vexriscv_smp/boot-helper.S

@@ -3,7 +3,6 @@
 .global smp_lottery_target
 .global smp_lottery_lock
 .global smp_lottery_args
-.global smp_slave
 
 boot_helper:
 	sw x10, smp_lottery_args  , x14
@@ -14,16 +13,3 @@ boot_helper:
 	li x15, 1
 	sw x15, smp_lottery_lock, x14
 	jr x13
-	
-smp_slave:
-	lw a0, smp_lottery_lock
-	beqz a0, smp_slave
-	fence r, r
-
-	.word(0x100F) //i$ flush
-	lw x10, smp_lottery_args
-	lw x11, smp_lottery_args+4
-	lw x12, smp_lottery_args+8
-	lw x13, smp_lottery_target
-	jr x13
-

litex/soc/cores/cpu/vexriscv_smp/crt0.S

@@ -56,13 +56,13 @@ trap_entry:
   addi sp,sp,16*4
   mret
   .text
-  
+
 crt_init:
   la sp, _fstack + 4
   la a0, trap_entry
   csrw mtvec, a0
   sw x0, smp_lottery_lock, a1
-  
+
 data_init:
   la a0, _fdata
   la a1, _edata
@@ -75,13 +75,23 @@ data_loop:
   add a2,a2,4
   j data_loop
 data_done:
-  
+
 smp_tyranny:
   csrr a0, mhartid
   beqz a0, bss_init
   call smp_slave
 
+smp_slave:
+  lw a0, smp_lottery_lock
+  beqz a0, smp_slave
+  fence r, r
 
+  .word(0x100F) //i$ flush
+  lw x10, smp_lottery_args
+  lw x11, smp_lottery_args+4
+  lw x12, smp_lottery_args+8
+  lw x13, smp_lottery_target
+  jr x13
 
 bss_init:
   la a0, _fbss

litex/soc/software/demo/Makefile

@@ -18,7 +18,7 @@ demo.elf: $(OBJECTS)
 	$(LD) $(LDFLAGS) \
 		-T linker.ld \
 		-N -o $@ \
-		 $(BUILD_DIR)/software/libbase/crt0.o \
+		$(BUILD_DIR)/software/libbase/crt0.o \
 		$(OBJECTS) \
 		-L$(BUILD_DIR)/software/libbase \
 		-L$(BUILD_DIR)/software/libcompiler_rt \