Use speed from device tree for serial console. Makes it possible to boot

and install systems where the firmware uses a non-standard speed.  This is
important for various boards that use a Rockchip SoC where the vendor thinks
using 1500000 bps as the serial console speed is a good idea (it isn't).

ok deraadt@, visa@, patrick@

3 files changed, 35 insertions, 7 deletions

diff --git a/sys/arch/arm64/arm64/machdep.c b/sys/arch/arm64/arm64/machdep.c
index efb99c6e626..cebcdec787f 100644
--- a/sys/arch/arm64/arm64/machdep.c
+++ b/sys/arch/arm64/arm64/machdep.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: machdep.c,v 1.31 2018/03/29 21:35:23 patrick Exp $ */
+/* $OpenBSD: machdep.c,v 1.32 2018/05/06 17:16:48 kettenis Exp $ */
 /*
  * Copyright (c) 2014 Patrick Wildt <patrick@blueri.se>
  *
@@ -56,7 +56,8 @@ uint8_t *bootmac = NULL;
 
 extern uint64_t esym;
 
-int stdout_node = 0;
+int stdout_node;
+int stdout_speed;
 
 void (*cpuresetfn)(void);
 void (*powerdownfn)(void);
@@ -150,6 +151,30 @@ inittodr(time_t base)
 	printf("WARNING: CHECK AND RESET THE DATE!\n");
 }
 
+static int
+atoi(const char *s)
+{
+	int n, neg;
+
+	n = 0;
+	neg = 0;
+
+	while (*s == '-') {
+		s++;
+		neg = !neg;
+	}
+
+	while (*s != '\0') {
+		if (*s < '0' || *s > '9')
+			break;
+
+		n = (10 * n) + (*s - '0');
+		s++;
+	}
+
+	return (neg ? -n : n);
+}
+
 void *
 fdt_find_cons(const char *name)
 {
@@ -165,8 +190,10 @@ fdt_find_cons(const char *name)
 		if (fdt_node_property(node, "stdout-path", &stdout) > 0) {
 			if (strchr(stdout, ':') != NULL) {
 				strlcpy(buf, stdout, sizeof(buf));
-				if ((p = strchr(buf, ':')) != NULL)
-					*p = '\0';
+				if ((p = strchr(buf, ':')) != NULL) {
+					*p++ = '\0';
+					stdout_speed = atoi(p);
+				}
 				stdout = buf;
 			}
 			if (stdout[0] != '/') {
diff --git a/sys/arch/arm64/dev/com_fdt.c b/sys/arch/arm64/dev/com_fdt.c
index 0b0e08f0a00..3a9b925e67d 100644
--- a/sys/arch/arm64/dev/com_fdt.c
+++ b/sys/arch/arm64/dev/com_fdt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: com_fdt.c,v 1.4 2018/04/02 12:59:39 kettenis Exp $ */
+/* $OpenBSD: com_fdt.c,v 1.5 2018/05/06 17:16:48 kettenis Exp $ */
 /*
  * Copyright (c) 2016 Patrick Wildt <patrick@blueri.se>
  *
@@ -80,7 +80,6 @@ com_fdt_init_cons(void)
 	if (bus_space_map(comconsiot, reg.addr, reg.size, 0, &comconsioh))
 		return;
 
-	comconsrate = B115200;
 	cn_tab = &com_fdt_cons;
 }
 
@@ -136,6 +135,7 @@ com_fdt_attach(struct device *parent, struct device *self, void *aux)
 		SET(sc->sc_hwflags, COM_HW_CONSOLE);
 		SET(sc->sc_swflags, COM_SW_SOFTCAR);
 		comconsfreq = sc->sc_frequency;
+		comconsrate = stdout_speed ? stdout_speed : B115200;
 	}
 
 	if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
diff --git a/sys/arch/arm64/include/fdt.h b/sys/arch/arm64/include/fdt.h
index b60077ca82e..2ec9cc06b65 100644
--- a/sys/arch/arm64/include/fdt.h
+++ b/sys/arch/arm64/include/fdt.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: fdt.h,v 1.3 2018/03/20 23:04:48 patrick Exp $ */
+/* $OpenBSD: fdt.h,v 1.4 2018/05/06 17:16:48 kettenis Exp $ */
 /*
  * Copyright (c) 2016 Patrick Wildt <patrick@blueri.se>
  *
@@ -35,6 +35,7 @@ struct fdt_attach_args {
 };
 
 extern int stdout_node;
+extern int stdout_speed;
 extern bus_space_tag_t fdt_cons_bs_tag;
 
 void *fdt_find_cons(const char *);