ports/qemu-{arm,riscv}: Use Picolibc 1.7.5 --crt0=semihost

This new crt0 provides argc/argv from the semihost command line rather than requiring parsing inside the application. Version 1.7.5 also provides a working gettimeofday. Signed-off-by: Keith Packard <keithp@keithp.com>
keith-packard · Mar 27, 2022 · 53a3d3c · 53a3d3c
1 parent 74e19c3
commit 53a3d3c
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Showing 4 changed files with 39 additions and 43 deletions.
diff --git a/chips/qemu/snek-qemu.c b/chips/qemu/snek-qemu.c
@@ -36,8 +36,12 @@
 #include <snek.h>
 #include <snek-io.h>
 #ifdef HAVE_SEMIHOST
+#define _HAVE_SEMIHOST
+#endif
+#ifdef _HAVE_SEMIHOST
 #include <semihost.h>
 #endif
+#include <sys/time.h>
 
 snek_poly_t
 snek_builtin_exit(snek_poly_t a)
@@ -84,42 +88,36 @@ snek_builtin_random_randrange(snek_poly_t a)
 	return snek_float_to_poly(random_x % mod);
 }
 
-#ifdef HAVE_SEMIHOST
 static uint32_t
 centisecs(void)
 {
-	/* QEMU uses real time for elapsed, but CPU time for clock */
-	uint64_t elapsed = sys_semihost_elapsed();
-	uint64_t tickfreq = sys_semihost_tickfreq();
+#ifdef _HAVE_SEMIHOST
+	return (uint32_t) (sys_semihost_elapsed() / (sys_semihost_tickfreq()/100));
+#else
+	struct timeval tv;
+	gettimeofday(&tv, NULL);
 
-	return (uint32_t) (elapsed / (tickfreq / 100));
-}
+	uint32_t centi = tv.tv_sec * 100 + tv.tv_usec / 10000;
+	return centi;
 #endif
+}
 
 snek_poly_t
 snek_builtin_time_monotonic(void)
 {
-#ifdef HAVE_SEMIHOST
 	return snek_float_to_poly((float) centisecs() * 0.01f);
-#else
-	static float now;
-	now += 0.01;
-	return snek_float_to_poly(now);
-#endif
 }
 
 snek_poly_t
 snek_builtin_time_sleep(snek_poly_t a)
 {
-#ifdef  HAVE_SEMIHOST
 	if (snek_poly_type(a) == snek_float) {
 		int32_t csecs = floorf(snek_poly_to_float(a) * 100.0f);
 		uint32_t then = centisecs() + csecs;
 
 		while ((int32_t) (then - centisecs()) > 0)
 			;
 	}
-#endif
 	return SNEK_NULL;
 }
 
@@ -133,29 +131,15 @@ int snek_qemu_getc(void)
 	return snek_io_getc(stdin);
 }
 
-#ifdef HAVE_SEMIHOST
-#define CMDLINE_SIZE 128
-static char cmdline[CMDLINE_SIZE];
-#endif
-
 int
-main(void)
+main(int argc, char **argv)
 {
 	snek_init();
 
-#ifdef HAVE_SEMIHOST
 	char *file = NULL;
 
-	/* This returns the whole command line, including  argv[0] */
-	if (sys_semihost_get_cmdline(cmdline, CMDLINE_SIZE - 1) == 0) {
-
-		/* Skip to the first argument. This assumes there
-		 * are no spaces in the command name
-		 */
-		file = strchr(cmdline, ' ');
-		if (file)
-			file++;
-	}
+	if (argc > 1)
+		file = argv[1];
 
 	if (file) {
 		snek_file = file;
@@ -164,9 +148,7 @@ main(void)
 			printf("\"%s\": cannot open\n", file);
 			exit(1);
 		}
-	} else
-#endif
-	{
+	} else {
 		snek_interactive = true;
 		printf("Welcome to snek " SNEK_VERSION "\n");
 	}

diff --git a/chips/qemu/snek-qemu.defs b/chips/qemu/snek-qemu.defs
@@ -36,7 +36,7 @@ PICOLIBC_CFLAGS= \
 
 OPT?=-Os
 
-CFLAGS=$(ARCH_CFLAGS) --oslib=semihost \
+CFLAGS=$(ARCH_CFLAGS) --oslib=semihost --crt0=semihost \
 	-std=gnu99 $(OPT) -g \
 	-I. -I$(SNEK_QEMU) -I$(SNEK_ROOT) $(PICOLIBC_CFLAGS) $(SNEK_CFLAGS)
 

diff --git a/ports/qemu-arm/snek-arm.in b/ports/qemu-arm/snek-arm.in
@@ -1,14 +1,21 @@
 #!/bin/sh
 here=`dirname $0`
-args="arg='snek'"
+args=""
 extra=""
 for i in "$@"; do
     case "$i" in
 	-*)
 	    extra="$extra $i"
 	    ;;
 	*)
-	    args="$args,arg=$i"
+	    case "$args" in
+		"")
+		    args="$i"
+		    ;;
+		*)
+		    args="$args $i"
+		    ;;
+	    esac
 	    ;;
     esac
 done
@@ -19,5 +26,5 @@ cpu=cortex-m3
 chardev="-chardev stdio,mux=on,id=stdio0"
 serial="-serial none"
 mon="-monitor none"
-semihost="-semihosting-config enable=on,chardev=stdio0,$args"
-$qemu $chardev $serial $mon $semihost -machine $machine -cpu $cpu -kernel $elf -nographic -bios none $extra
+semihost="enable=on,chardev=stdio0,arg=$args"
+$qemu $chardev $serial $mon -semihosting-config "$semihost" -machine $machine -cpu $cpu -kernel $elf -nographic -bios none $extra
diff --git a/ports/qemu-riscv/snek-riscv.in b/ports/qemu-riscv/snek-riscv.in
@@ -1,14 +1,21 @@
 #!/bin/sh
 here=`dirname $0`
-args="arg='snek'"
+args=""
 extra=""
 for i in "$@"; do
     case "$i" in
 	-*)
 	    extra="$extra $i"
 	    ;;
 	*)
-	    args="$args,arg=$i"
+	    case "$args" in
+		"")
+		    args="$i"
+		    ;;
+		*)
+		    args="$args $i"
+		    ;;
+	    esac
 	    ;;
     esac
 done
@@ -19,5 +26,5 @@ cpu=sifive-e31
 chardev="-chardev stdio,mux=on,id=stdio0"
 serial="-serial none"
 mon="-monitor none"
-semihost="-semihosting-config enable=on,chardev=stdio0,$args"
-$qemu $chardev $serial $mon $semihost -machine $machine -cpu $cpu -kernel $elf -nographic -bios none $extra
+semihost="enable=on,chardev=stdio0,arg=$args"
+$qemu $chardev $serial $mon -semihosting-config "$semihost" -machine $machine -cpu $cpu -kernel $elf -nographic -bios none $extra