Using newlib libc from riscv-tools in dhrystone benchmark

6 files changed, 262 insertions, 227 deletions

diff --git a/dhrystone/Makefile b/dhrystone/Makefile
index 255749d..3609a97 100644
--- a/dhrystone/Makefile
+++ b/dhrystone/Makefile
@@ -1,7 +1,14 @@
-
-OBJS = start.o dhry_1.o dhry_2.o stdlib.o
-CFLAGS = -MD -O3 -m32 -march=RV32IM -ffreestanding -nostdlib -DTIME -DRISCV
-TOOLCHAIN_PREFIX = riscv32-unknown-elf-
+USE_MYSTDLIB = 0
+OBJS = dhry_1.o dhry_2.o stdlib.o
+CFLAGS = -MD -O3 -m32 -march=RV32IM -DTIME -DRISCV
+TOOLCHAIN_PREFIX = /opt/riscv32im/bin/riscv32-unknown-elf-
+
+ifeq ($(USE_MYSTDLIB),1)
+CFLAGS += -DUSE_MYSTDLIB -ffreestanding -nostdlib
+OBJS += start.o
+else
+OBJS += syscalls.o
+endif
 
 test: testbench.vvp dhry.hex
 	vvp -N testbench.vvp
@@ -21,16 +28,18 @@ timing.vvp: testbench.v ../picorv32.v
 	iverilog -o timing.vvp -DTIMING testbench.v ../picorv32.v
 	chmod -x timing.vvp
 
-dhry.hex: dhry.bin ../firmware/makehex.py
-	python3 ../firmware/makehex.py $< 16384 > $@
+dhry.hex: dhry.elf
+	riscv32-unknown-elf-objcopy -O verilog $< $@
 
-dhry.bin: dhry.elf
-	$(TOOLCHAIN_PREFIX)objcopy -O binary $< $@
+ifeq ($(USE_MYSTDLIB),1)
+dhry.elf: $(OBJS) sections.lds
+	$(TOOLCHAIN_PREFIX)gcc $(CFLAGS) -Wl,-Bstatic,-T,sections.lds,-Map,dhry.map,--strip-debug -o $@ $(OBJS) -lgcc
 	chmod -x $@
-	
-dhry.elf: $(OBJS) ../firmware/sections.lds
-	$(TOOLCHAIN_PREFIX)gcc $(CFLAGS) -Wl,-Bstatic,-T,../firmware/sections.lds,-Map,dhry.map,--strip-debug -o $@ $(OBJS) -lgcc
+else
+dhry.elf: $(OBJS)
+	$(TOOLCHAIN_PREFIX)gcc $(CFLAGS) -Wl,-Bstatic,-Map,dhry.map,--strip-debug -o $@ $(OBJS) -lgcc -lc
 	chmod -x $@
+endif
 
 %.o: %.c
 	$(TOOLCHAIN_PREFIX)gcc -c $(CFLAGS) $<
diff --git a/dhrystone/dhry_1.c b/dhrystone/dhry_1.c
index 884c613..fa0d4d9 100644
--- a/dhrystone/dhry_1.c
+++ b/dhrystone/dhry_1.c
@@ -17,6 +17,13 @@
 
 #include "dhry.h"
 
+#ifdef USE_MYSTDLIB
+extern char     *malloc ();
+#else
+#  include <stdlib.h>
+#  include <string.h>
+#endif
+
 /* Global Variables: */
 
 Rec_Pointer     Ptr_Glob,
@@ -28,7 +35,6 @@ char            Ch_1_Glob,
 int             Arr_1_Glob [50];
 int             Arr_2_Glob [50] [50];
 
-extern char     *malloc ();
 Enumeration     Func_1 ();
   /* forward declaration necessary since Enumeration may not simply be int */
 
@@ -43,7 +49,7 @@ Enumeration     Func_1 ();
 
 /* variables for time measurement: */
 
-#ifdef TIMES
+#ifdef IGN_TIMES
 struct tms      time_info;
 extern  int     times ();
                 /* see library function "times" */
@@ -124,9 +130,9 @@ main ()
   }
   printf ("Please give the number of runs through the benchmark: ");
   {
-    int n;
-    scanf ("%d", &n);
-    Number_Of_Runs = n;
+    // int n;
+    // scanf ("%d", &n);
+    Number_Of_Runs = 100;
   }
   printf ("\n");
 
@@ -136,7 +142,7 @@ main ()
   /* Start timer */
   /***************/
 
-#ifdef TIMES
+#ifdef IGN_TIMES
   times (&time_info);
   Begin_Time = (long) time_info.tms_utime;
 #endif
@@ -197,7 +203,7 @@ main ()
   /* Stop timer */
   /**************/
 
-#ifdef TIMES
+#ifdef IGN_TIMES
   times (&time_info);
   End_Time = (long) time_info.tms_utime;
 #endif
diff --git a/dhrystone/sections.lds b/dhrystone/sections.lds
new file mode 100644
index 0000000..3efb873
--- /dev/null
+++ b/dhrystone/sections.lds
@@ -0,0 +1,18 @@
+/*
+This is free and unencumbered software released into the public domain.
+
+Anyone is free to copy, modify, publish, use, compile, sell, or
+distribute this software, either in source code form or as a compiled
+binary, for any purpose, commercial or non-commercial, and by any
+means.
+*/
+
+SECTIONS {
+	.memory : {
+		. = 0x10000;
+		start*(.text);
+		*(.text);
+		*(*);
+		end = .;
+	}
+}
diff --git a/dhrystone/stdlib.c b/dhrystone/stdlib.c
index b4d2a2f..55150a7 100644
--- a/dhrystone/stdlib.c
+++ b/dhrystone/stdlib.c
@@ -1,18 +1,27 @@
+// This is free and unencumbered software released into the public domain.
+//
+// Anyone is free to copy, modify, publish, use, compile, sell, or
+// distribute this software, either in source code form or as a compiled
+// binary, for any purpose, commercial or non-commercial, and by any
+// means.
+
 #include <stdarg.h>
+#include <stdint.h>
 
 extern long time();
 extern long insn();
+
+#ifdef USE_MYSTDLIB
 extern char *malloc();
 extern int printf(const char *format, ...);
-extern int scanf(const char *format, ...);
 
-// implementations are copy&paste from riscv newlib
 extern void *memcpy(void *dest, const void *src, long n);
 extern char *strcpy(char *dest, const char *src);
 extern int strcmp(const char *s1, const char *s2);
 
 char heap_memory[1024];
 int heap_memory_used = 0;
+#endif
 
 long time()
 {
@@ -30,6 +39,7 @@ long insn()
 	return insns;
 }
 
+#ifdef USE_MYSTDLIB
 char *malloc(int size)
 {
 	char *p = heap_memory + heap_memory_used;
@@ -96,213 +106,105 @@ int printf(const char *format, ...)
 	va_end(ap);
 }
 
-int scanf(const char *format, ...)
+void *memcpy(void *aa, const void *bb, long n)
 {
-	// printf("[scanf(\"%s\")]\n", format);
-	va_list ap;
-	va_start(ap, format);
-	*va_arg(ap,int*) = 100;
-	va_end(ap);
-	return 0;
+	// printf("**MEMCPY**\n");
+	char *a = aa;
+	const char *b = bb;
+	while (n--) *(a++) = *(b++);
+	return aa;
 }
 
-// -------------------------------------------------------
-// Copy&paste from RISC-V newlib:
-
-void* memcpy(void* aa, const void* bb, long n)
+char *strcpy(char* dst, const char* src)
 {
-  #define BODY(a, b, t) { \
-    t tt = *b; \
-    a++, b++; \
-    *(a-1) = tt; \
-  }
-
-  char* a = (char*)aa;
-  const char* b = (const char*)bb;
-  char* end = a+n;
-  unsigned long msk = sizeof(long)-1;
-  if (__builtin_expect(((unsigned long)a & msk) != ((unsigned long)b & msk) || n < sizeof(long), 0))
-  {
-small:
-    if (__builtin_expect(a < end, 1))
-      while (a < end)
-        BODY(a, b, char);
-    return aa;
-  }
-
-  if (__builtin_expect(((unsigned long)a & msk) != 0, 0))
-    while ((unsigned long)a & msk)
-      BODY(a, b, char);
-
-  long* la = (long*)a;
-  const long* lb = (const long*)b;
-  long* lend = (long*)((unsigned long)end & ~msk);
-
-  if (__builtin_expect(la < lend-8, 0))
-  {
-    while (la < lend-8)
-    {
-      long b0 = *lb++;
-      long b1 = *lb++;
-      long b2 = *lb++;
-      long b3 = *lb++;
-      long b4 = *lb++;
-      long b5 = *lb++;
-      long b6 = *lb++;
-      long b7 = *lb++;
-      long b8 = *lb++;
-      *la++ = b0;
-      *la++ = b1;
-      *la++ = b2;
-      *la++ = b3;
-      *la++ = b4;
-      *la++ = b5;
-      *la++ = b6;
-      *la++ = b7;
-      *la++ = b8;
-    }
-  }
-
-  while (la < lend)
-    BODY(la, lb, long);
-
-  a = (char*)la;
-  b = (const char*)lb;
-  if (__builtin_expect(a < end, 0))
-    goto small;
-  return aa;
-}
+	char *r = dst;
 
-static inline unsigned long __libc_detect_null(unsigned long w)
-{
-  unsigned long mask = 0x7f7f7f7f;
-  if (sizeof(long) == 8)
-    mask = ((mask << 16) << 16) | mask;
-  return ~(((w & mask) + mask) | w | mask);
+	while ((((uint32_t)dst | (uint32_t)src) & 3) != 0)
+	{
+		char c = *(src++);
+		*(dst++) = c;
+		if (!c) return r;
+	}
+
+	while (1)
+	{
+		uint32_t v = *(uint32_t*)src;
+
+		if (__builtin_expect((((v) - 0x01010101UL) & ~(v) & 0x80808080UL), 0))
+		{
+			dst[0] = v & 0xff;
+			if ((v & 0xff) == 0)
+				return r;
+			v = v >> 8;
+
+			dst[1] = v & 0xff;
+			if ((v & 0xff) == 0)
+				return r;
+			v = v >> 8;
+
+			dst[2] = v & 0xff;
+			if ((v & 0xff) == 0)
+				return r;
+			v = v >> 8;
+
+			dst[3] = v & 0xff;
+			return r;
+		}
+
+		*(uint32_t*)dst = v;
+		src += 4;
+		dst += 4;
+	}
 }
 
-char* strcpy(char* dst, const char* src)
+int strcmp(const char *s1, const char *s2)
 {
-  char* dst0 = dst;
-
-#if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__)
-  int misaligned = ((unsigned long)dst | (unsigned long)src) & (sizeof(long)-1);
-  if (__builtin_expect(!misaligned, 1))
-  {
-    long* ldst = (long*)dst;
-    const long* lsrc = (const long*)src;
-
-    while (!__libc_detect_null(*lsrc))
-      *ldst++ = *lsrc++;
-
-    dst = (char*)ldst;
-    src = (const char*)lsrc;
-
-    char c0 = src[0];
-    char c1 = src[1];
-    char c2 = src[2];
-    if (!(*dst++ = c0)) return dst0;
-    if (!(*dst++ = c1)) return dst0;
-    char c3 = src[3];
-    if (!(*dst++ = c2)) return dst0;
-    if (sizeof(long) == 4) goto out;
-    char c4 = src[4];
-    if (!(*dst++ = c3)) return dst0;
-    char c5 = src[5];
-    if (!(*dst++ = c4)) return dst0;
-    char c6 = src[6];
-    if (!(*dst++ = c5)) return dst0;
-    if (!(*dst++ = c6)) return dst0;
-
-out:
-    *dst++ = 0;
-    return dst0;
-  }
-#endif /* not PREFER_SIZE_OVER_SPEED */
-
-  char ch;
-  do
-  {
-    ch = *src;
-    src++;
-    dst++;
-    *(dst-1) = ch;
-  } while(ch);
-
-  return dst0;
+	while ((((uint32_t)s1 | (uint32_t)s2) & 3) != 0)
+	{
+		char c1 = *(s1++);
+		char c2 = *(s2++);
+
+		if (c1 != c2)
+			return c1 < c2 ? -1 : +1;
+		else if (!c1)
+			return 0;
+	}
+
+	while (1)
+	{
+		uint32_t v1 = *(uint32_t*)s1;
+		uint32_t v2 = *(uint32_t*)s2;
+
+		if (__builtin_expect(v1 != v2, 0))
+		{
+			char c1, c2;
+
+			c1 = v1 & 0xff, c2 = v2 & 0xff;
+			if (c1 != c2) return c1 < c2 ? -1 : +1;
+			if (!c1) return 0;
+			v1 = v1 >> 8, v2 = v2 >> 8;
+
+			c1 = v1 & 0xff, c2 = v2 & 0xff;
+			if (c1 != c2) return c1 < c2 ? -1 : +1;
+			if (!c1) return 0;
+			v1 = v1 >> 8, v2 = v2 >> 8;
+
+			c1 = v1 & 0xff, c2 = v2 & 0xff;
+			if (c1 != c2) return c1 < c2 ? -1 : +1;
+			if (!c1) return 0;
+			v1 = v1 >> 8, v2 = v2 >> 8;
+
+			c1 = v1 & 0xff, c2 = v2 & 0xff;
+			if (c1 != c2) return c1 < c2 ? -1 : +1;
+			return 0;
+		}
+
+		if (__builtin_expect((((v1) - 0x01010101UL) & ~(v1) & 0x80808080UL), 0))
+			return 0;
+
+		s1 += 4;
+		s2 += 4;
+	}
 }
+#endif
 
-/* copy&paste from disassembled libc */
-// strcmp.S: Artisanally coded in California by A. Shell Waterman
-asm (
-"               .global strcmp;      "
-"  strcmp:      or      a4,a0,a1;    "
-"               li      t2,-1;       "
-"               andi    a4,a4,3;     "
-"               bnez    a4,.K1;      "
-"               lui     t3,0x7f7f8;  "
-"               addi    t3,t3,-129;  "
-"  .K6:         lw      a2,0(a0);    "
-"               lw      a3,0(a1);    "
-"               and     t0,a2,t3;    "
-"               or      t1,a2,t3;    "
-"               add     t0,t0,t3;    "
-"               or      t0,t0,t1;    "
-"               bne     t0,t2,.K2;   "
-"               bne     a2,a3,.K3;   "
-"               lw      a2,4(a0);    "
-"               lw      a3,4(a1);    "
-"               and     t0,a2,t3;    "
-"               or      t1,a2,t3;    "
-"               add     t0,t0,t3;    "
-"               or      t0,t0,t1;    "
-"               bne     t0,t2,.K4;   "
-"               bne     a2,a3,.K3;   "
-"               lw      a2,8(a0);    "
-"               lw      a3,8(a1);    "
-"               and     t0,a2,t3;    "
-"               or      t1,a2,t3;    "
-"               add     t0,t0,t3;    "
-"               or      t0,t0,t1;    "
-"               bne     t0,t2,.K5;   "
-"               addi    a0,a0,12;    "
-"               addi    a1,a1,12;    "
-"               beq     a2,a3,.K6;   "
-"  .K3:         slli    a4,a2,0x10;  "
-"               slli    a5,a3,0x10;  "
-"               bne     a4,a5,.K7;   "
-"               srli    a4,a2,0x10;  "
-"               srli    a5,a3,0x10;  "
-"               sub     a0,a4,a5;    "
-"               andi    a1,a0,255;   "
-"               bnez    a1,.K8;      "
-"               ret;                 "
-"  .K7:         srli    a4,a4,0x10;  "
-"               srli    a5,a5,0x10;  "
-"               sub     a0,a4,a5;    "
-"               andi    a1,a0,255;   "
-"               bnez    a1,.K8;      "
-"               ret;                 "
-"  .K8:         andi    a4,a4,255;   "
-"               andi    a5,a5,255;   "
-"               sub     a0,a4,a5;    "
-"               ret;                 "
-"  .K1:         lbu     a2,0(a0);    "
-"               lbu     a3,0(a1);    "
-"               addi    a0,a0,1;     "
-"               addi    a1,a1,1;     "
-"               bne     a2,a3,.K9;   "
-"               bnez    a2,.K1;      "
-"  .K9:         sub     a0,a2,a3;    "
-"               ret;                 "
-"  .K4:         addi    a0,a0,4;     "
-"               addi    a1,a1,4;     "
-"  .K2:         bne     a2,a3,.K1;   "
-"               li      a0,0;        "
-"               ret;                 "
-"  .K5:         addi    a0,a0,8;     "
-"               addi    a1,a1,8;     "
-"               bne     a2,a3,.K1;   "
-"               li      a0,0;        "
-"               ret;                 "
-);
diff --git a/dhrystone/syscalls.c b/dhrystone/syscalls.c
new file mode 100644
index 0000000..cdf872f
--- /dev/null
+++ b/dhrystone/syscalls.c
@@ -0,0 +1,95 @@
+// An extremely minimalist syscalls.c for newlib
+// Based on riscv newlib libgloss/riscv/machine/syscall.h
+// Written by Clifford Wolf.
+
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+
+#define UNIMPL_FUNC(_f) ".globl " #_f "\n.type " #_f ", @function\n" #_f ":\n"
+
+asm (
+	".text\n"
+	".align 2\n"
+	UNIMPL_FUNC(open)
+	UNIMPL_FUNC(openat)
+	UNIMPL_FUNC(lseek)
+	UNIMPL_FUNC(stat)
+	UNIMPL_FUNC(lstat)
+	UNIMPL_FUNC(fstatat)
+	UNIMPL_FUNC(isatty)
+	UNIMPL_FUNC(access)
+	UNIMPL_FUNC(faccessat)
+	UNIMPL_FUNC(link)
+	UNIMPL_FUNC(unlink)
+	UNIMPL_FUNC(execve)
+	UNIMPL_FUNC(getpid)
+	UNIMPL_FUNC(fork)
+	UNIMPL_FUNC(kill)
+	UNIMPL_FUNC(wait)
+	UNIMPL_FUNC(times)
+	UNIMPL_FUNC(gettimeofday)
+	UNIMPL_FUNC(ftime)
+	UNIMPL_FUNC(utime)
+	UNIMPL_FUNC(chown)
+	UNIMPL_FUNC(chmod)
+	UNIMPL_FUNC(chdir)
+	UNIMPL_FUNC(getcwd)
+	UNIMPL_FUNC(sysconf)
+	"j unimplemented_syscall\n"
+);
+
+void unimplemented_syscall()
+{
+	const char *p = "Unimplemented system call called!\n";
+	while (*p)
+		*(volatile int*)0x10000000 = *(p++);
+	asm volatile ("ebreak");
+	__builtin_unreachable();
+}
+
+ssize_t read(int file, void *ptr, size_t len)
+{
+	// always EOF
+	return 0;
+}
+
+ssize_t write(int file, const void *ptr, size_t len)
+{
+	const void *eptr = ptr + len;
+	while (ptr != eptr)
+		*(volatile int*)0x10000000 = *(char*)(ptr++);
+	return len;
+}
+
+int close(int file) 
+{
+	// close is called before _exit()
+	return 0;
+}
+
+int fstat(int file, struct stat *st)
+{
+	// fstat is called during libc startup
+	errno = ENOENT;
+	return -1;
+}
+
+void *sbrk(ptrdiff_t incr)
+{
+	extern unsigned char _end[];	// Defined by linker
+	static unsigned long heap_end;
+
+	if (heap_end == 0)
+		heap_end = (long)_end;
+
+	heap_end += incr;
+	return (void *)(heap_end - incr);
+}
+
+void _exit(int exit_status)
+{
+	asm volatile ("ebreak");
+	__builtin_unreachable();
+}
+
diff --git a/dhrystone/testbench.v b/dhrystone/testbench.v
index a00e8f4..2d985d6 100644
--- a/dhrystone/testbench.v
+++ b/dhrystone/testbench.v
@@ -29,7 +29,9 @@ module testbench;
 	picorv32 #(
 		.BARREL_SHIFTER(1),
 		.ENABLE_MUL(1),
-		.ENABLE_DIV(1)
+		.ENABLE_DIV(1),
+		.PROGADDR_RESET('h10000),
+		.STACKADDR('h10000)
 	) uut (
 		.clk         (clk        ),
 		.resetn      (resetn     ),
@@ -48,13 +50,16 @@ module testbench;
 		.mem_la_wstrb(mem_la_wstrb)
 	);
 
-	reg [31:0] memory [0:64*1024/4-1];
+	reg [7:0] memory [0:256*1024-1];
 	initial $readmemh("dhry.hex", memory);
 
 	assign mem_ready = 1;
 
 	always @(posedge clk) begin
-		mem_rdata <= mem_la_read ? memory[mem_la_addr >> 2] : 'bx;
+		mem_rdata[ 7: 0] <= mem_la_read ? memory[mem_la_addr + 0] : 'bx;
+		mem_rdata[15: 8] <= mem_la_read ? memory[mem_la_addr + 1] : 'bx;
+		mem_rdata[23:16] <= mem_la_read ? memory[mem_la_addr + 2] : 'bx;
+		mem_rdata[31:24] <= mem_la_read ? memory[mem_la_addr + 3] : 'bx;
 		if (mem_la_write) begin
 			case (mem_la_addr)
 				32'h1000_0000: begin
@@ -64,10 +69,10 @@ module testbench;
 `endif
 				end
 				default: begin
-					if (mem_la_wstrb[0]) memory[mem_la_addr >> 2][ 7: 0] <= mem_la_wdata[ 7: 0];
-					if (mem_la_wstrb[1]) memory[mem_la_addr >> 2][15: 8] <= mem_la_wdata[15: 8];
-					if (mem_la_wstrb[2]) memory[mem_la_addr >> 2][23:16] <= mem_la_wdata[23:16];
-					if (mem_la_wstrb[3]) memory[mem_la_addr >> 2][31:24] <= mem_la_wdata[31:24];
+					if (mem_la_wstrb[0]) memory[mem_la_addr + 0] <= mem_la_wdata[ 7: 0];
+					if (mem_la_wstrb[1]) memory[mem_la_addr + 1] <= mem_la_wdata[15: 8];
+					if (mem_la_wstrb[2]) memory[mem_la_addr + 2] <= mem_la_wdata[23:16];
+					if (mem_la_wstrb[3]) memory[mem_la_addr + 3] <= mem_la_wdata[31:24];
 				end
 			endcase
 		end