Split /dev/nvram driver out of isa/clock.c for i386 and amd64. I have not

refactored it to be a generic device.
Instead of being part of the standard kernel, there is now a 'nvram' device
for i386/amd64.  It is in DEFAULTS like io and mem, and can be turned off
with 'nodevice nvram'.  This matches the previous behavior when it was
first committed.

sys/amd64/conf/DEFAULTS

@@ -11,6 +11,7 @@ device		isa
 # Pseudo devices.
 device		mem		# Memory and kernel memory devices
 device		io		# I/O device
+device		nvram		# Access to rtc cmos via /dev/nvram
 
 # UART chips on this platform
 device		uart_ns8250

sys/amd64/include/clock.h

@@ -31,7 +31,8 @@ void	i8254_init(void);
 
 int	acquire_timer2(int mode);
 int	release_timer2(void);
-int	rtcin(int val);
+int	rtcin(int reg);
+void	writertc(int reg, unsigned char val);
 int	sysbeep(int pitch, int period);
 void	init_TSC(void);
 void	init_TSC_tc(void);

sys/amd64/isa/clock.c

@@ -433,7 +433,7 @@ rtcin(reg)
 	return (val);
 }
 
-static void
+void
 writertc(int reg, u_char val)
 {
 
@@ -934,99 +934,4 @@ static devclass_t attimer_devclass;
 DRIVER_MODULE(attimer, isa, attimer_driver, attimer_devclass, 0, 0);
 DRIVER_MODULE(attimer, acpi, attimer_driver, attimer_devclass, 0, 0);
 
-/*
- * Linux-style /dev/nvram driver
- *
- * cmos ram starts at bytes 14 through 128, for a total of 114 bytes.
- * bytes 16 through 31 are checksummed at byte 32.
- * Unlike Linux, you have to take care of the checksums yourself.
- * The driver exposes byte 14 as file offset 0.
- */
-
-#define NVRAM_FIRST	RTC_DIAG	/* 14 */
-#define NVRAM_LAST	128
-
-static d_open_t		nvram_open;
-static d_read_t		nvram_read;
-static d_write_t	nvram_write;
-
-static struct cdev *nvram_dev;
-
-static struct cdevsw nvram_cdevsw = {
-	.d_version =	D_VERSION,
-	.d_flags =	D_NEEDGIANT,
-	.d_open =	nvram_open,
-	.d_read =	nvram_read,
-	.d_write =	nvram_write,
-	.d_name =	"nvram",
-};
-
-static int
-nvram_open(struct cdev *dev __unused, int flags, int fmt __unused,
-    struct thread *td)
-{
-	int error = 0;
-
-	if (flags & FWRITE)
-		error = securelevel_gt(td->td_ucred, 0);
-
-	return (error);
-}
-
-static int
-nvram_read(struct cdev *dev, struct uio *uio, int flags)
-{
-	int nv_off;
-	u_char v;
-	int error = 0;
-
-	while (uio->uio_resid > 0 && error == 0) {
-		nv_off = uio->uio_offset + NVRAM_FIRST;
-		if (nv_off < NVRAM_FIRST || nv_off >= NVRAM_LAST)
-			return (0);	/* Signal EOF */
-		/* Single byte at a time */
-		v = rtcin(nv_off);
-		error = uiomove(&v, 1, uio);
-	}
-	return (error);
-
-}
-
-static int
-nvram_write(struct cdev *dev, struct uio *uio, int flags)
-{
-	int nv_off;
-	u_char v;
-	int error = 0;
-
-	while (uio->uio_resid > 0 && error == 0) {
-		nv_off = uio->uio_offset + NVRAM_FIRST;
-		if (nv_off < NVRAM_FIRST || nv_off >= NVRAM_LAST)
-			return (0);	/* Signal EOF */
-		/* Single byte at a time */
-		error = uiomove(&v, 1, uio);
-		writertc(nv_off, v);
-	}
-	return (error);
-}
-
-static int
-nvram_modevent(module_t mod __unused, int type, void *data __unused)
-{
-	switch (type) {
-	case MOD_LOAD:
-		nvram_dev = make_dev(&nvram_cdevsw, 0,
-		    UID_ROOT, GID_KMEM, 0640, "nvram");
-		break;
-	case MOD_UNLOAD:
-	case MOD_SHUTDOWN:
-		destroy_dev(nvram_dev);
-		break;
-	default:
-		return (EOPNOTSUPP);
-	}
-	return (0);
-}
-DEV_MODULE(nvram, nvram_modevent, NULL);
-
 #endif /* DEV_ISA */

sys/conf/files.amd64

@@ -185,6 +185,7 @@ dev/kbd/kbd.c			optional	atkbd | sc | ukbd
 dev/mem/memutil.c		optional	mem
 dev/nfe/if_nfe.c		optional	nfe pci
 dev/nve/if_nve.c		optional	nve pci
+dev/nvram/nvram.c		optional	nvram isa
 dev/rr232x/os_bsd.c		optional	rr232x
 dev/rr232x/osm_bsd.c		optional	rr232x
 dev/rr232x/rr232x_config.c	optional	rr232x

sys/conf/files.i386

@@ -211,6 +211,7 @@ dev/mse/mse.c			optional mse
 dev/mse/mse_isa.c		optional mse isa
 dev/nfe/if_nfe.c		optional nfe pci
 dev/nve/if_nve.c		optional nve pci
+dev/nvram/nvram.c		optional nvram isa
 dev/pcf/pcf_isa.c		optional pcf
 dev/random/nehemiah.c		optional random
 dev/rr232x/os_bsd.c		optional rr232x

sys/dev/nvram/nvram.c

@@ -0,0 +1,159 @@
+/*-
+ * Copyright (c) 2007 Peter Wemm
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/conf.h>
+#include <sys/fcntl.h>
+#include <sys/proc.h>
+#include <sys/uio.h>
+#include <sys/module.h>
+
+#include <machine/clock.h>
+#include <isa/rtc.h>
+
+/*
+ * Linux-style /dev/nvram driver
+ *
+ * cmos ram starts at bytes 14 through 128, for a total of 114 bytes.
+ * The driver exposes byte 14 as file offset 0.
+ *
+ * Offsets 2 through 31 are checksummed at offset 32, 33.
+ * In order to avoid the possibility of making the machine unbootable at the
+ * bios level (press F1 to continue!), we refuse to allow writes if we do
+ * not see a pre-existing valid checksum.  If the existing sum is invalid,
+ * then presumably we do not know how to make a sum that the bios will accept.
+ */
+
+#define NVRAM_FIRST	RTC_DIAG	/* 14 */
+#define NVRAM_LAST	128
+
+#define CKSUM_FIRST	2
+#define CKSUM_LAST	31
+#define CKSUM_MSB	32
+#define CKSUM_LSB	33
+
+static d_open_t		nvram_open;
+static d_read_t		nvram_read;
+static d_write_t	nvram_write;
+
+static struct cdev *nvram_dev;
+
+static struct cdevsw nvram_cdevsw = {
+	.d_version =	D_VERSION,
+	.d_flags =	D_NEEDGIANT,
+	.d_open =	nvram_open,
+	.d_read =	nvram_read,
+	.d_write =	nvram_write,
+	.d_name =	"nvram",
+};
+
+static int
+nvram_open(struct cdev *dev __unused, int flags, int fmt __unused,
+    struct thread *td)
+{
+	int error = 0;
+
+	if (flags & FWRITE)
+		error = securelevel_gt(td->td_ucred, 0);
+
+	return (error);
+}
+
+static int
+nvram_read(struct cdev *dev, struct uio *uio, int flags)
+{
+	int nv_off;
+	u_char v;
+	int error = 0;
+
+	while (uio->uio_resid > 0 && error == 0) {
+		nv_off = uio->uio_offset + NVRAM_FIRST;
+		if (nv_off < NVRAM_FIRST || nv_off >= NVRAM_LAST)
+			return (0);	/* Signal EOF */
+		/* Single byte at a time */
+		v = rtcin(nv_off);
+		error = uiomove(&v, 1, uio);
+	}
+	return (error);
+
+}
+
+static int
+nvram_write(struct cdev *dev, struct uio *uio, int flags)
+{
+	int nv_off;
+	u_char v;
+	int error = 0;
+	int i;
+	uint16_t sum;
+
+	/* Assert that we understand the existing checksum first!  */
+	sum = rtcin(NVRAM_FIRST + CKSUM_MSB) << 8 |
+	      rtcin(NVRAM_FIRST + CKSUM_LSB);
+	for (i = CKSUM_FIRST; i <= CKSUM_LAST; i++)
+		sum -= rtcin(NVRAM_FIRST + i);
+	if (sum != 0)
+		return (EIO);
+	/* Bring in user data and write */
+	while (uio->uio_resid > 0 && error == 0) {
+		nv_off = uio->uio_offset + NVRAM_FIRST;
+		if (nv_off < NVRAM_FIRST || nv_off >= NVRAM_LAST)
+			return (0);	/* Signal EOF */
+		/* Single byte at a time */
+		error = uiomove(&v, 1, uio);
+		writertc(nv_off, v);
+	}
+	/* Recalculate checksum afterwards */
+	sum = 0;
+	for (i = CKSUM_FIRST; i <= CKSUM_LAST; i++)
+		sum += rtcin(NVRAM_FIRST + i);
+	writertc(NVRAM_FIRST + CKSUM_MSB, sum >> 8);
+	writertc(NVRAM_FIRST + CKSUM_LSB, sum);
+	return (error);
+}
+
+static int
+nvram_modevent(module_t mod __unused, int type, void *data __unused)
+{
+	switch (type) {
+	case MOD_LOAD:
+		nvram_dev = make_dev(&nvram_cdevsw, 0,
+		    UID_ROOT, GID_KMEM, 0640, "nvram");
+		break;
+	case MOD_UNLOAD:
+	case MOD_SHUTDOWN:
+		destroy_dev(nvram_dev);
+		break;
+	default:
+		return (EOPNOTSUPP);
+	}
+	return (0);
+}
+DEV_MODULE(nvram, nvram_modevent, NULL);

sys/i386/conf/DEFAULTS

@@ -15,6 +15,7 @@ device		npx
 # Pseudo devices.
 device		mem		# Memory and kernel memory devices
 device		io		# I/O device
+device		nvram		# Access to rtc cmos via /dev/nvram
 
 # UART chips on this platform
 device		uart_ns8250

sys/i386/include/clock.h

@@ -31,7 +31,8 @@ void	i8254_init(void);
 
 int	acquire_timer2(int mode);
 int	release_timer2(void);
-int	rtcin(int val);
+int	rtcin(int reg);
+void	writertc(int reg, unsigned char val);
 int	sysbeep(int pitch, int period);
 void	timer_restore(void);
 void	init_TSC(void);

sys/i386/isa/clock.c

@@ -438,7 +438,7 @@ rtcin(reg)
 	return (val);
 }
 
-static void
+void
 writertc(int reg, u_char val)
 {
 
@@ -938,99 +938,4 @@ static devclass_t attimer_devclass;
 DRIVER_MODULE(attimer, isa, attimer_driver, attimer_devclass, 0, 0);
 DRIVER_MODULE(attimer, acpi, attimer_driver, attimer_devclass, 0, 0);
 
-/*
- * Linux-style /dev/nvram driver
- *
- * cmos ram starts at bytes 14 through 128, for a total of 114 bytes.
- * bytes 16 through 31 are checksummed at byte 32.
- * Unlike Linux, you have to take care of the checksums yourself.
- * The driver exposes byte 14 as file offset 0.
- */
-
-#define NVRAM_FIRST	RTC_DIAG	/* 14 */
-#define NVRAM_LAST	128
-
-static d_open_t		nvram_open;
-static d_read_t		nvram_read;
-static d_write_t	nvram_write;
-
-static struct cdev *nvram_dev;
-
-static struct cdevsw nvram_cdevsw = {
-	.d_version =	D_VERSION,
-	.d_flags =	D_NEEDGIANT,
-	.d_open =	nvram_open,
-	.d_read =	nvram_read,
-	.d_write =	nvram_write,
-	.d_name =	"nvram",
-};
-
-static int
-nvram_open(struct cdev *dev __unused, int flags, int fmt __unused,
-    struct thread *td)
-{
-	int error = 0;
-
-	if (flags & FWRITE)
-		error = securelevel_gt(td->td_ucred, 0);
-
-	return (error);
-}
-
-static int
-nvram_read(struct cdev *dev, struct uio *uio, int flags)
-{
-	int nv_off;
-	u_char v;
-	int error = 0;
-
-	while (uio->uio_resid > 0 && error == 0) {
-		nv_off = uio->uio_offset + NVRAM_FIRST;
-		if (nv_off < NVRAM_FIRST || nv_off >= NVRAM_LAST)
-			return (0);	/* Signal EOF */
-		/* Single byte at a time */
-		v = rtcin(nv_off);
-		error = uiomove(&v, 1, uio);
-	}
-	return (error);
-
-}
-
-static int
-nvram_write(struct cdev *dev, struct uio *uio, int flags)
-{
-	int nv_off;
-	u_char v;
-	int error = 0;
-
-	while (uio->uio_resid > 0 && error == 0) {
-		nv_off = uio->uio_offset + NVRAM_FIRST;
-		if (nv_off < NVRAM_FIRST || nv_off >= NVRAM_LAST)
-			return (0);	/* Signal EOF */
-		/* Single byte at a time */
-		error = uiomove(&v, 1, uio);
-		writertc(nv_off, v);
-	}
-	return (error);
-}
-
-static int
-nvram_modevent(module_t mod __unused, int type, void *data __unused)
-{
-	switch (type) {
-	case MOD_LOAD:
-		nvram_dev = make_dev(&nvram_cdevsw, 0,
-		    UID_ROOT, GID_KMEM, 0640, "nvram");
-		break;
-	case MOD_UNLOAD:
-	case MOD_SHUTDOWN:
-		destroy_dev(nvram_dev);
-		break;
-	default:
-		return (EOPNOTSUPP);
-	}
-	return (0);
-}
-DEV_MODULE(nvram, nvram_modevent, NULL);
-
 #endif /* DEV_ISA */

sys/isa/atrtc.c

@@ -438,7 +438,7 @@ rtcin(reg)
 	return (val);
 }
 
-static void
+void
 writertc(int reg, u_char val)
 {
 
@@ -938,99 +938,4 @@ static devclass_t attimer_devclass;
 DRIVER_MODULE(attimer, isa, attimer_driver, attimer_devclass, 0, 0);
 DRIVER_MODULE(attimer, acpi, attimer_driver, attimer_devclass, 0, 0);
 
-/*
- * Linux-style /dev/nvram driver
- *
- * cmos ram starts at bytes 14 through 128, for a total of 114 bytes.
- * bytes 16 through 31 are checksummed at byte 32.
- * Unlike Linux, you have to take care of the checksums yourself.
- * The driver exposes byte 14 as file offset 0.
- */
-
-#define NVRAM_FIRST	RTC_DIAG	/* 14 */
-#define NVRAM_LAST	128
-
-static d_open_t		nvram_open;
-static d_read_t		nvram_read;
-static d_write_t	nvram_write;
-
-static struct cdev *nvram_dev;
-
-static struct cdevsw nvram_cdevsw = {
-	.d_version =	D_VERSION,
-	.d_flags =	D_NEEDGIANT,
-	.d_open =	nvram_open,
-	.d_read =	nvram_read,
-	.d_write =	nvram_write,
-	.d_name =	"nvram",
-};
-
-static int
-nvram_open(struct cdev *dev __unused, int flags, int fmt __unused,
-    struct thread *td)
-{
-	int error = 0;
-
-	if (flags & FWRITE)
-		error = securelevel_gt(td->td_ucred, 0);
-
-	return (error);
-}
-
-static int
-nvram_read(struct cdev *dev, struct uio *uio, int flags)
-{
-	int nv_off;
-	u_char v;
-	int error = 0;
-
-	while (uio->uio_resid > 0 && error == 0) {
-		nv_off = uio->uio_offset + NVRAM_FIRST;
-		if (nv_off < NVRAM_FIRST || nv_off >= NVRAM_LAST)
-			return (0);	/* Signal EOF */
-		/* Single byte at a time */
-		v = rtcin(nv_off);
-		error = uiomove(&v, 1, uio);
-	}
-	return (error);
-
-}
-
-static int
-nvram_write(struct cdev *dev, struct uio *uio, int flags)
-{
-	int nv_off;
-	u_char v;
-	int error = 0;
-
-	while (uio->uio_resid > 0 && error == 0) {
-		nv_off = uio->uio_offset + NVRAM_FIRST;
-		if (nv_off < NVRAM_FIRST || nv_off >= NVRAM_LAST)
-			return (0);	/* Signal EOF */
-		/* Single byte at a time */
-		error = uiomove(&v, 1, uio);
-		writertc(nv_off, v);
-	}
-	return (error);
-}
-
-static int
-nvram_modevent(module_t mod __unused, int type, void *data __unused)
-{
-	switch (type) {
-	case MOD_LOAD:
-		nvram_dev = make_dev(&nvram_cdevsw, 0,
-		    UID_ROOT, GID_KMEM, 0640, "nvram");
-		break;
-	case MOD_UNLOAD:
-	case MOD_SHUTDOWN:
-		destroy_dev(nvram_dev);
-		break;
-	default:
-		return (EOPNOTSUPP);
-	}
-	return (0);
-}
-DEV_MODULE(nvram, nvram_modevent, NULL);
-
 #endif /* DEV_ISA */

sys/modules/Makefile

@@ -188,6 +188,7 @@ SUBDIR=	${_3dfx} \
 	ntfs_iconv \
 	nullfs \
 	${_nve} \
+	${_nvram} \
 	${_nwfs} \
 	${_nxge} \
 	${_oltr} \
@@ -202,7 +203,6 @@ SUBDIR=	${_3dfx} \
 	plip \
 	${_pmc} \
 	portalfs \
-	${_powermac_nvram} \
 	ppbus \
 	ppc \
 	ppi \
@@ -399,6 +399,7 @@ _mse=		mse
 _ncp=		ncp
 .endif
 _ncv=		ncv
+_nvram=		nvram
 _ndis=		ndis
 _nsp=		nsp
 .if ${MK_NCP} != "no"
@@ -519,6 +520,7 @@ _mly=		mly
 _ndis=		ndis
 _nfe=		nfe
 _nve=		nve
+_nvram=		nvram
 _nxge=		nxge
 _pccard=	pccard
 _rr232x=	rr232x
@@ -579,7 +581,7 @@ _ath_hal=	ath_hal
 _ath_rate_amrr=	ath_rate_amrr
 _ath_rate_onoe=	ath_rate_onoe
 _ath_rate_sample=ath_rate_sample
-_powermac_nvram=	powermac_nvram
+_nvram=		powermac_nvram
 _smbfs=		smbfs
 .endif
 

sys/modules/nvram/Makefile

@@ -0,0 +1,8 @@
+# $FreeBSD$
+
+.PATH: ${.CURDIR}/../../dev/nvram
+
+KMOD=	nvram
+SRCS=	nvram.c
+
+.include <bsd.kmod.mk>