Merge pull request #64 from sifive/multicore-scratchpad

Add support for multicore systems and scratchpad-only systems

18 files changed, 313 insertions, 10 deletions

diff --git a/.gitignore b/.gitignore
index 0b8d3e8..534c2dc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,15 @@
 *.a
 work/
 toolchain/
+
+software/coremark/coremark
+software/coreplexip_welcome/coreplexip_welcome
+software/demo_gpio/demo_gpio
+software/dhrystone/dhrystone
+software/double_tap_dontboot/double_tap_dontboot
+software/global_interrupts/global_interrupts
+software/hello/hello
+software/led_fade/led_fade
+software/local_interrupts/local_interrupts
+software/performance_counters/performance_counters
+software/smp/smp
diff --git a/Makefile b/Makefile
index eedb007..11f239f 100644
--- a/Makefile
+++ b/Makefile
@@ -14,6 +14,7 @@ endif
 # Default target
 BOARD ?= freedom-e300-hifive1
 PROGRAM ?= demo_gpio
+LINK_TARGET ?= flash
 GDB_PORT ?= 3333
 
 # Variables the user probably shouldn't override.
@@ -191,11 +192,11 @@ PROGRAM_ELF = software/$(PROGRAM)/$(PROGRAM)
 
 .PHONY: software_clean
 software_clean:
-	$(MAKE) -C $(PROGRAM_DIR) BSP_BASE=$(abspath bsp) BOARD=$(BOARD) clean
+	$(MAKE) -C $(PROGRAM_DIR) CC=$(RISCV_GCC) RISCV_ARCH=$(RISCV_ARCH) RISCV_ABI=$(RISCV_ABI) AR=$(RISCV_AR) BSP_BASE=$(abspath bsp) BOARD=$(BOARD) LINK_TARGET=$(LINK_TARGET) clean
 
 .PHONY: software
 software: software_clean
-	$(MAKE) -C $(PROGRAM_DIR) CC=$(RISCV_GCC) RISCV_ARCH=$(RISCV_ARCH) RISCV_ABI=$(RISCV_ABI) AR=$(RISCV_AR) BSP_BASE=$(abspath bsp) BOARD=$(BOARD)
+	$(MAKE) -C $(PROGRAM_DIR) CC=$(RISCV_GCC) RISCV_ARCH=$(RISCV_ARCH) RISCV_ABI=$(RISCV_ABI) AR=$(RISCV_AR) BSP_BASE=$(abspath bsp) BOARD=$(BOARD) LINK_TARGET=$(LINK_TARGET)
 
 dasm: software $(RISCV_OBJDUMP)
 	$(RISCV_OBJDUMP) -D $(PROGRAM_ELF)
diff --git a/bsp/env/common.mk b/bsp/env/common.mk
index 32703a6..4566b80 100644
--- a/bsp/env/common.mk
+++ b/bsp/env/common.mk
@@ -15,7 +15,7 @@ ASM_SRCS += $(ENV_DIR)/start.S
 ASM_SRCS += $(ENV_DIR)/entry.S
 C_SRCS += $(PLATFORM_DIR)/init.c
 
-LINKER_SCRIPT := $(PLATFORM_DIR)/link.lds
+LINKER_SCRIPT := $(PLATFORM_DIR)/$(LINK_TARGET).lds
 
 INCLUDES += -I$(BSP_BASE)/include
 INCLUDES += -I$(BSP_BASE)/drivers/
diff --git a/bsp/env/coreplexip-e31-arty/link.lds b/bsp/env/coreplexip-e31-arty/flash.lds
index 590c5b6..590c5b6 100644
--- a/bsp/env/coreplexip-e31-arty/link.lds
+++ b/bsp/env/coreplexip-e31-arty/flash.lds
diff --git a/bsp/env/coreplexip-e31-arty/init.c b/bsp/env/coreplexip-e31-arty/init.c
index 05b2b3e..84ae09e 100644
--- a/bsp/env/coreplexip-e31-arty/init.c
+++ b/bsp/env/coreplexip-e31-arty/init.c
@@ -6,12 +6,16 @@
 #include "platform.h"
 #include "encoding.h"
 
+#define CPU_FREQ 65000000
+#define XSTR(x) #x
+#define STR(x) XSTR(x)
+
 extern int main(int argc, char** argv);
 extern void trap_entry();
 
 static unsigned long get_cpu_freq()
 {
-  return 65000000;
+  return CPU_FREQ;
 }
 
 unsigned long get_timer_freq()
@@ -83,7 +87,7 @@ void _init()
   #ifndef NO_INIT
   uart_init(115200);
 
-  printf("core freq at %d Hz\n", get_cpu_freq());
+  puts("core freq at " STR(CPU_FREQ) " Hz\n");
 
   write_csr(mtvec, &trap_entry);
   #endif
diff --git a/bsp/env/coreplexip-e31-arty/scratchpad.lds b/bsp/env/coreplexip-e31-arty/scratchpad.lds
new file mode 100644
index 0000000..7887c13
--- /dev/null
+++ b/bsp/env/coreplexip-e31-arty/scratchpad.lds
@@ -0,0 +1,161 @@
+OUTPUT_ARCH( "riscv" )
+
+ENTRY( _start )
+
+MEMORY
+{
+  ram (wxa!ri) : ORIGIN = 0x80000000, LENGTH = 16K
+}
+
+PHDRS
+{
+  ram PT_LOAD;
+  ram_init PT_LOAD;
+  ram PT_NULL;
+}
+
+SECTIONS
+{
+  __stack_size = DEFINED(__stack_size) ? __stack_size : 1K;
+
+  .init           :
+  {
+    KEEP (*(SORT_NONE(.init)))
+  } >ram AT>ram :ram
+
+  .text           :
+  {
+    *(.text.unlikely .text.unlikely.*)
+    *(.text.startup .text.startup.*)
+    *(.text .text.*)
+    *(.gnu.linkonce.t.*)
+  } >ram AT>ram :ram
+
+  .fini           :
+  {
+    KEEP (*(SORT_NONE(.fini)))
+  } >ram AT>ram :ram
+
+  PROVIDE (__etext = .);
+  PROVIDE (_etext = .);
+  PROVIDE (etext = .);
+
+  .rodata         :
+  {
+    *(.rdata)
+    *(.rodata .rodata.*)
+    *(.gnu.linkonce.r.*)
+  } >ram AT>ram :ram
+
+  . = ALIGN(4);
+
+  .preinit_array  :
+  {
+    PROVIDE_HIDDEN (__preinit_array_start = .);
+    KEEP (*(.preinit_array))
+    PROVIDE_HIDDEN (__preinit_array_end = .);
+  } >ram AT>ram :ram
+
+  .init_array     :
+  {
+    PROVIDE_HIDDEN (__init_array_start = .);
+    KEEP (*(SORT_BY_INIT_PRIORITY(.init_array.*) SORT_BY_INIT_PRIORITY(.ctors.*)))
+    KEEP (*(.init_array EXCLUDE_FILE (*crtbegin.o *crtbegin?.o *crtend.o *crtend?.o ) .ctors))
+    PROVIDE_HIDDEN (__init_array_end = .);
+  } >ram AT>ram :ram
+
+  .fini_array     :
+  {
+    PROVIDE_HIDDEN (__fini_array_start = .);
+    KEEP (*(SORT_BY_INIT_PRIORITY(.fini_array.*) SORT_BY_INIT_PRIORITY(.dtors.*)))
+    KEEP (*(.fini_array EXCLUDE_FILE (*crtbegin.o *crtbegin?.o *crtend.o *crtend?.o ) .dtors))
+    PROVIDE_HIDDEN (__fini_array_end = .);
+  } >ram AT>ram :ram
+
+  .ctors          :
+  {
+    /* gcc uses crtbegin.o to find the start of
+       the constructors, so we make sure it is
+       first.  Because this is a wildcard, it
+       doesn't matter if the user does not
+       actually link against crtbegin.o; the
+       linker won't look for a file to match a
+       wildcard.  The wildcard also means that it
+       doesn't matter which directory crtbegin.o
+       is in.  */
+    KEEP (*crtbegin.o(.ctors))
+    KEEP (*crtbegin?.o(.ctors))
+    /* We don't want to include the .ctor section from
+       the crtend.o file until after the sorted ctors.
+       The .ctor section from the crtend file contains the
+       end of ctors marker and it must be last */
+    KEEP (*(EXCLUDE_FILE (*crtend.o *crtend?.o ) .ctors))
+    KEEP (*(SORT(.ctors.*)))
+    KEEP (*(.ctors))
+  } >ram AT>ram :ram
+
+  .dtors          :
+  {
+    KEEP (*crtbegin.o(.dtors))
+    KEEP (*crtbegin?.o(.dtors))
+    KEEP (*(EXCLUDE_FILE (*crtend.o *crtend?.o ) .dtors))
+    KEEP (*(SORT(.dtors.*)))
+    KEEP (*(.dtors))
+  } >ram AT>ram :ram
+
+  .lalign         :
+  {
+    . = ALIGN(4);
+    PROVIDE( _data_lma = . );
+  } >ram AT>ram :ram
+
+  .dalign         :
+  {
+    . = ALIGN(4);
+    PROVIDE( _data = . );
+  } >ram AT>ram :ram_init
+
+  .data          :
+  {
+    *(.data .data.*)
+    *(.gnu.linkonce.d.*)
+    . = ALIGN(8);
+    PROVIDE( __global_pointer$ = . + 0x800 );
+    *(.sdata .sdata.*)
+    *(.gnu.linkonce.s.*)
+    . = ALIGN(8);
+    *(.srodata.cst16)
+    *(.srodata.cst8)
+    *(.srodata.cst4)
+    *(.srodata.cst2)
+    *(.srodata .srodata.*)
+  } >ram AT>ram :ram_init
+
+  . = ALIGN(4);
+  PROVIDE( _edata = . );
+  PROVIDE( edata = . );
+
+  PROVIDE( _fbss = . );
+  PROVIDE( __bss_start = . );
+  .bss            :
+  {
+    *(.sbss*)
+    *(.gnu.linkonce.sb.*)
+    *(.bss .bss.*)
+    *(.gnu.linkonce.b.*)
+    *(COMMON)
+    . = ALIGN(4);
+  } >ram AT>ram :ram
+
+  . = ALIGN(8);
+  PROVIDE( _end = . );
+  PROVIDE( end = . );
+
+  .stack :
+  {
+    . = ALIGN(8);
+    . += __stack_size;
+    PROVIDE( _sp = . );
+    PROVIDE( _heap_end = . );
+  } >ram AT>ram :ram
+}
diff --git a/bsp/env/coreplexip-e51-arty/flash.lds b/bsp/env/coreplexip-e51-arty/flash.lds
new file mode 120000
index 0000000..54c1026
--- /dev/null
+++ b/bsp/env/coreplexip-e51-arty/flash.lds
@@ -0,0 +1 @@
+../coreplexip-e31-arty/flash.lds
\ No newline at end of file
diff --git a/bsp/env/coreplexip-e51-arty/link.lds b/bsp/env/coreplexip-e51-arty/link.lds
deleted file mode 120000
index f3e0254..0000000
--- a/bsp/env/coreplexip-e51-arty/link.lds
+++ /dev/null
@@ -1 +0,0 @@
-../coreplexip-e31-arty/link.lds
\ No newline at end of file
diff --git a/bsp/env/coreplexip-e51-arty/scratchpad.lds b/bsp/env/coreplexip-e51-arty/scratchpad.lds
new file mode 120000
index 0000000..7fbe10a
--- /dev/null
+++ b/bsp/env/coreplexip-e51-arty/scratchpad.lds
@@ -0,0 +1 @@
+../coreplexip-e31-arty/scratchpad.lds
\ No newline at end of file
diff --git a/bsp/env/freedom-e300-arty/flash.lds b/bsp/env/freedom-e300-arty/flash.lds
new file mode 120000
index 0000000..6441ce5
--- /dev/null
+++ b/bsp/env/freedom-e300-arty/flash.lds
@@ -0,0 +1 @@
+../freedom-e300-hifive1/flash.lds
\ No newline at end of file
diff --git a/bsp/env/freedom-e300-arty/link.lds b/bsp/env/freedom-e300-arty/link.lds
deleted file mode 120000
index 2c48449..0000000
--- a/bsp/env/freedom-e300-arty/link.lds
+++ /dev/null
@@ -1 +0,0 @@
-../freedom-e300-hifive1/link.lds
\ No newline at end of file
diff --git a/bsp/env/freedom-e300-hifive1/link.lds b/bsp/env/freedom-e300-hifive1/flash.lds
index 6b37141..6b37141 100644
--- a/bsp/env/freedom-e300-hifive1/link.lds
+++ b/bsp/env/freedom-e300-hifive1/flash.lds
diff --git a/bsp/env/start.S b/bsp/env/start.S
index e86105b..4e9f665 100644
--- a/bsp/env/start.S
+++ b/bsp/env/start.S
@@ -1,18 +1,27 @@
 // See LICENSE for license details.
+#include <sifive/smp.h>
 
-// See LICENSE for license details.
+/* This is defined in sifive/platform.h, but that can't be included from
+ * assembly. */
+#define CLINT_CTRL_ADDR 0x02000000
 
 	.section .init
 	.globl _start
 	.type _start,@function
 
 _start:
+	.cfi_startproc
+	.cfi_undefined ra
 .option push
 .option norelax
 	la gp, __global_pointer$
 .option pop
 	la sp, _sp
 
+#if defined(ENABLE_SMP)
+	smp_pause(t0, t1)
+#endif
+
 	/* Load data section */
 	la a0, _data_lma
 	la a1, _data
@@ -52,11 +61,51 @@ _start:
 1:
 #endif
 
+#if defined(ENABLE_SMP)
+	smp_resume(t0, t1)
+
+	csrr a0, mhartid
+	bnez a0, 2f
+#endif
+
+	auipc ra, 0
+	addi sp, sp, -16
+#if __riscv_xlen == 32
+	sw ra, 8(sp)
+#else
+	sd ra, 8(sp)
+#endif
+
 	/* argc = argv = 0 */
 	li a0, 0
 	li a1, 0
 	call main
 	tail exit
+1:
+	j 1b
+
+#if defined(ENABLE_SMP)
+2:
+	la t0, trap_entry
+	csrw mtvec, t0
+
+	csrr a0, mhartid
+	la t1, _sp
+	slli t0, a0, 10
+	sub sp, t1, t0
+
+	auipc ra, 0
+	addi sp, sp, -16
+#if __riscv_xlen == 32
+	sw ra, 8(sp)
+#else
+	sd ra, 8(sp)
+#endif
+
+	call secondary_main
+	tail exit
 
 1:
 	j 1b
+#endif
+	.cfi_endproc
diff --git a/software/hello/hello.c b/software/hello/hello.c
index 85c5d87..befc6ee 100644
--- a/software/hello/hello.c
+++ b/software/hello/hello.c
@@ -2,7 +2,7 @@
 
 int main()
 {
-  printf("hello world!\n");
+  puts("hello world!\n");
 
   return 0;
 }
diff --git a/software/led_fade/.unsupported-boards b/software/led_fade/.unsupported-boards
index ad80e34..f9e9897 100644
--- a/software/led_fade/.unsupported-boards
+++ b/software/led_fade/.unsupported-boards
@@ -1,4 +1,4 @@
 freedom-e300-arty
 coreplexip-e31-arty
 coreplexip-e51-arty
-
+freedom-e300-arty
diff --git a/software/smp/Makefile b/software/smp/Makefile
new file mode 100644
index 0000000..4131ffc
--- /dev/null
+++ b/software/smp/Makefile
@@ -0,0 +1,6 @@
+TARGET = smp
+C_SRCS += smp.c
+CFLAGS += -O2 -fno-builtin-printf -DENABLE_SMP
+
+BSP_BASE = ../../bsp
+include $(BSP_BASE)/env/common.mk
diff --git a/software/smp/atomic.h b/software/smp/atomic.h
new file mode 100644
index 0000000..074c6a2
--- /dev/null
+++ b/software/smp/atomic.h
@@ -0,0 +1,29 @@
+#ifndef SIFIVE_ATOMIC_H
+#define SIFIVE_ATOMIC_H
+
+#define ATOMIC_INIT(x)		\
+	{			\
+		.counter = (x),	\
+	}
+
+typedef struct {
+  int counter;
+} atomic_t;
+
+static inline int atomic_xchg(atomic_t *v, int n)
+{
+  register int c;
+
+  __asm__ __volatile__ (
+    "amoswap.w.aqrl %0, %2, %1"
+    : "=r" (c), "+A" (v->counter)
+    : "r" (n));
+  return c;
+}
+
+static inline void mb(void)
+{
+  __asm__ __volatile__ ("fence");
+}
+
+#endif
diff --git a/software/smp/smp.c b/software/smp/smp.c
new file mode 100644
index 0000000..36c9db9
--- /dev/null
+++ b/software/smp/smp.c
@@ -0,0 +1,40 @@
+#include <stdio.h>
+#include <unistd.h>
+#include "atomic.h"
+void write_hex(int, unsigned long);
+
+atomic_t tty_lock = ATOMIC_INIT(0);
+
+void get_lock(atomic_t *lock)
+{
+  while (atomic_xchg(lock, 1) == 1);
+  mb();
+}
+
+void put_lock(atomic_t *lock)
+{
+  mb();
+  atomic_xchg(lock, 0);
+}
+
+int secondary_main(int hartid)
+{
+  volatile int counter;
+
+  while (1) {
+    get_lock(&tty_lock);
+    write(1, "hello world from hart ", 22);
+    char s[] = {'0', '\n', '\0'};
+    s[0] += hartid;
+    write(1, s, 2);
+    put_lock(&tty_lock);
+
+    for (counter = 0; counter < 10000 + 100*hartid; ++counter)
+        mb();
+  }
+}
+
+int main()
+{
+  return secondary_main(0);
+}