[PATCH] Added Getentropy() support to beagle BSP
Udit agarwal
dev.madaari at gmail.com
Thu Mar 15 04:56:45 UTC 2018
Hi,
Below is the updated patch along with the one for atsam. Please have a look.
Moreover, in error case(FRO unwanted shutdown), Error bit of status
register turns zero, indicating that FRO is no longer running.Untill now, i
haven't came across any situation where this bit turns 0. In the NETBSD
<http://ftp.netbsd.org/pub/NetBSD/NetBSD-current/src/sys/arch/arm/omap/am335x_trng.c>
and in linux kernel
<https://github.com/torvalds/linux/blob/68fed41e0ff6c0332520a0d70ac05be2a7d9130e/drivers/char/hw_random/omap-rng.c>
(line 241 ) implementation of am335x_trng, it seems they aren't checking
for this bit. Instead they are only using RNG_STATUS_RDY as an indication
of successful random data generation.
*Patch: atsam*
>From ae0c79ae4850503259c64387dea69346e7d7b1d4 Mon Sep 17 00:00:00 2001
From: Udit agarwal <dev.madaari at gmail.com>
Date: Thu, 15 Mar 2018 09:43:13 +0530
Subject: [PATCH] Fixed mutual exclusion of critical section
---
c/src/lib/libbsp/arm/atsam/startup/getentropy-trng.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/c/src/lib/libbsp/arm/atsam/startup/getentropy-trng.c
b/c/src/lib/libbsp/arm/atsam/startup/getentropy-trng.c
index 11e24dc..b26b6a8 100644
--- a/c/src/lib/libbsp/arm/atsam/startup/getentropy-trng.c
+++ b/c/src/lib/libbsp/arm/atsam/startup/getentropy-trng.c
@@ -17,6 +17,8 @@
#include <string.h>
#include <rtems/sysinit.h>
+static rtems_mutex atsam_trng_reg =
RTEMS_MUTEX_INITIALIZER("atsam_trng_reg");
+
static void atsam_trng_enable(void)
{
PMC_EnablePeripheral(ID_TRNG);
@@ -29,9 +31,12 @@ int getentropy(void *ptr, size_t n)
uint32_t random;
size_t copy;
+ rtems_mutex_lock(&atsam_trng_reg);
while ((TRNG_GetStatus() & TRNG_ISR_DATRDY) == 0) {
/* wait */
}
+
+ rtems_mutex_unlock(&atsam_trng_reg);
random = TRNG_GetRandData();
/*
@@ -51,6 +56,7 @@ int getentropy(void *ptr, size_t n)
ptr += copy;
}
+ rtems_mutex_destroy(&atsam_trng_reg);
return 0;
}
--
1.9.1
*Patch BBB*
>From ea885f9681c14f324917469b295e7489f56c10e7 Mon Sep 17 00:00:00 2001
From: Udit agarwal <dev.madaari at gmail.com>
Date: Thu, 15 Mar 2018 09:24:35 +0530
Subject: [PATCH] Added getentropy support to beagle BSP
---
bsps/arm/include/libcpu/am335x.h | 33 ++++++
c/src/lib/libbsp/arm/beagle/Makefile.am | 4 +-
c/src/lib/libbsp/arm/beagle/dev/bbb_getentropy.c | 126
+++++++++++++++++++++++
3 files changed, 162 insertions(+), 1 deletion(-)
create mode 100644 c/src/lib/libbsp/arm/beagle/dev/bbb_getentropy.c
diff --git a/bsps/arm/include/libcpu/am335x.h
b/bsps/arm/include/libcpu/am335x.h
index 367e97c..6170ef3 100644
--- a/bsps/arm/include/libcpu/am335x.h
+++ b/bsps/arm/include/libcpu/am335x.h
@@ -14,11 +14,17 @@
* Modified by Ben Gras <beng at shrike-systems.com> to add lots
* of beagleboard/beaglebone definitions, delete lpc32xx specific
* ones, and merge with some other header files.
+ *
+ * Modified by Udit agarwal <dev.madaari at gmail.com> to add random
+ * number generating module definitions and TRNG register structure.
*/
#if !defined(_AM335X_H_)
#define _AM335X_H_
+/* For TRNG register definition */
+#include <stdint.h>
+
/* Interrupt controller memory map */
#define OMAP3_DM37XX_INTR_BASE 0x48200000 /* INTCPS physical address */
@@ -701,4 +707,31 @@
#define AM335X_CM_PER_OCPWP_L3_CLKSTCTRL_CLKACTIVITY_OCPWP_L4_GCLK
(0x00000020u)
#define AM335X_I2C_INT_STOP_CONDITION AM335X_I2C_IRQSTATUS_BF
+/* TRNG Register */
+
+/* RNG base address */
+#define RNG_BASE 0x48310000
+/* RNG clock control */
+#define CM_PER_RNG_CLKCTRL (AM335X_CM_PER_ADDR | (9 << 4))
+/* rng module clock status bits */
+#define AM335X_CLK_RNG_BIT_MASK (0x30000)
+/* Offset from RNG base for output ready flag */
+#define RNG_STATUS_RDY (1u << 0)
+/* Offset from RNG base for FRO related error */
+#define RNG_STATUS_ERR (1u << 1)
+/* Offset from RNG base for clock status */
+#define RNG_STATUS_CLK (1u << 31)
+/* enable module */
+#define AM335X_RNG_ENABLE (1 << 10)
+
+/* TRNG register structure */
+typedef struct {
+ uint64_t output; /* 00 */
+ uint32_t status; /* 08 */
+ uint32_t irq_en; /* 0c */
+ uint32_t status_clr; /* 10 */
+ uint32_t control; /* 14 */
+ uint32_t config; /* 18 */
+} am335x_trng_register;
+
#endif
diff --git a/c/src/lib/libbsp/arm/beagle/Makefile.am
b/c/src/lib/libbsp/arm/beagle/Makefile.am
index 8251660..c483dc4 100644
--- a/c/src/lib/libbsp/arm/beagle/Makefile.am
+++ b/c/src/lib/libbsp/arm/beagle/Makefile.am
@@ -40,7 +40,6 @@ libbsp_a_LIBADD =
# Shared
libbsp_a_SOURCES += ../../shared/bootcard.c
-libbsp_a_SOURCES += ../../shared/getentropy-cpucounter.c
libbsp_a_SOURCES += ../../shared/src/bsp-fdt.c
libbsp_a_SOURCES += ../../shared/bspclean.c
libbsp_a_SOURCES += ../../shared/bspgetworkarea.c
@@ -88,6 +87,9 @@ libbsp_a_SOURCES += gpio/bbb-gpio.c
#pwm
libbsp_a_SOURCES += pwm/pwm.c
+#getentropy
+libbsp_a_SOURCES += dev/bbb_getentropy.c
+
#RTC
libbsp_a_SOURCES += rtc.c
libbsp_a_SOURCES += ../../shared/tod.c
diff --git a/c/src/lib/libbsp/arm/beagle/dev/bbb_getentropy.c
b/c/src/lib/libbsp/arm/beagle/dev/bbb_getentropy.c
new file mode 100644
index 0000000..5445331
--- /dev/null
+++ b/c/src/lib/libbsp/arm/beagle/dev/bbb_getentropy.c
@@ -0,0 +1,126 @@
+/**
+* @file
+*
+* @ingroup arm_beagle
+*
+* @brief Getentropy implementation on BeagleBone Black BSP
+*/
+
+/*
+* Copyright (c) 2018 Udit agarwal <dev.madaari at gmail.com>
+* 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.
+*/
+
+#include <libcpu/am335x.h>
+#include <unistd.h>
+#include <string.h>
+#include <rtems/sysinit.h>
+#include <rtems/thread.h>
+#include <stdint.h>
+
+/* max refill 34 * 256 cycles */
+#define AM335X_RNG_MAX_REFILL (34 << 16)
+/* min refill 33 * 64 cycles */
+#define AM335X_RNG_MIN_REFILL (33 << 0)
+/* startup 33 * 256 cycles */
+#define AM335X_RNG_STARTUP_CYCLES (33 << 16)
+
+static rtems_mutex am335x_trng_reg =
RTEMS_MUTEX_INITIALIZER("am335x_trng_reg");
+/* maximun and minimum refill cycle sets the number of samples to be taken
+ from FRO to generate random number */
+static void am335x_rng_enable(volatile am335x_trng_register *rng)
+{
+ rng->control = rng->config = 0;
+ rng->config |= AM335X_RNG_MIN_REFILL | AM335X_RNG_MAX_REFILL ;
+ rng->control |= AM335X_RNG_STARTUP_CYCLES | AM335X_RNG_ENABLE ;
+}
+
+static void am335x_rng_clock_enable(void)
+{
+ volatile am335x_trng_register *rng = (am335x_trng_register*) RNG_BASE;
+ *(volatile uint8_t *) CM_PER_RNG_CLKCTRL = 2;
+ while(
+ *(volatile uint32_t *) CM_PER_RNG_CLKCTRL &
+ AM335X_CLK_RNG_BIT_MASK
+ ) {
+ /* wait */
+ }
+ am335x_rng_enable(rng);
+}
+
+static uint64_t trng_getranddata(volatile am335x_trng_register *rng)
+{
+ uint64_t output = rng->output;
+ return output;
+}
+
+int getentropy(void *ptr, size_t n)
+{
+ volatile am335x_trng_register *rng = (am335x_trng_register*) RNG_BASE;
+ while (n > 0)
+ {
+ uint64_t random;
+ size_t copy;
+
+ /* for mutual exclusion synchronization between multiple
+ access to TRNG register in different contexts */
+ rtems_mutex_lock(&am335x_trng_reg);
+
+ /* wait untill RNG becomes ready with next set of random data */
+ while( ( rng->status & RNG_STATUS_RDY ) == 0 )
+ {
+ /* wait */
+ }
+
+ rtems_mutex_unlock(&am335x_trng_reg);
+ random = trng_getranddata(rng);
+
+ /* clear the status flag after reading to generate new random
+ value */
+ rng->status_clr = RNG_STATUS_RDY;
+
+ /* checking for error by masking all bits other then error bit in
+ status register */
+ if( ((rng->status & RNG_STATUS_ERR)>>1) == 1)
+ {
+ copy = sizeof(random);
+ if ( n < copy )
+ {
+ copy = n;
+ }
+ memcpy(ptr, &random, copy);
+ n -= copy;
+ ptr = (char*)ptr + copy;
+ }
+ }
+
+ rtems_mutex_destroy(&am335x_trng_reg);
+ return 0;
+}
+
+RTEMS_SYSINIT_ITEM(
+ am335x_rng_clock_enable,
+ RTEMS_SYSINIT_DEVICE_DRIVERS,
+ RTEMS_SYSINIT_ORDER_LAST
+);
--
1.9.1
On Wed, Mar 14, 2018 at 11:02 AM, Christian Mauderer <
christian.mauderer at embedded-brains.de> wrote:
>
> Am Mittwoch, 14. März 2018 schrieb Udit agarwal:
> > Hi,
> > @Joel This seems to be SoC specific.
> >
> >
> > So, here is the implementation with mutex, Do let me know if this is
> okay. I'll then do it for atsam also.
>
> Atsam should be an extra patch.
>
> >
> > int getentropy(void *ptr, size_t n)
> > {
> > volatile am335x_trng_register *rng = (am335x_trng_register*)
> RNG_BASE;
> > rtems_mutex lock_trng_reg = RTEMS_MUTEX_INITIALIZER("lock_
> trng_reg");
>
> If you create a local variable every thread will have it's own mutex. So
> they still can access the critical section in parallel. Use a global one in
> this case.
>
> >
> > while (n > 0)
> > {
> > uint64_t random;
> > size_t copy;
> >
> > /* for mutual exclusion synchronization between multiple
> > access to TRNG register in different contexts */
> > rtems_mutex_lock(&lock_trng_reg);
> >
> > /* wait untill RNG becomes ready with next set of random data */
> > while( ( rng->status & RNG_STATUS_RDY ) == 0 )
> > {
> > /* wait */
> > }
> >
> > random = trng_getranddata(rng);
> > /* clear the status flag after reading to generate new random
> > value */
> > rng->status_clr = RNG_STATUS_RDY;
> > rtems_mutex_unlock(&lock_trng_reg);
> >
> > /* checking for error by masking all bits other then error bit in
> > status register */
> > if( ((rng->status & RNG_STATUS_ERR)>>1) == 1)
> > {
> > copy = sizeof(random);
> > if ( n < copy )
> > {
> > copy = n;
> > }
> > memcpy(ptr, &random, copy);
> > n -= copy;
> > ptr = (char*)ptr + copy;
> > }
>
> Just noted that one: What Value is returned in the error case? Can the
> error even happen? I think that there is a special function that should be
> called in that case.
>
> > }
> >
> > rtems_mutex_destroy(&lock_trng_reg);
> > return 0;
> > }
> >
> >
> >
> >
> > On Wed, Mar 14, 2018 at 2:15 AM, Joel Sherrill <joel at rtems.org> wrote:
> >
> >
> >
> >
> >
> > On Mar 13, 2018 1:31 AM, "Sebastian Huber" <sebastian.huber at embedded-
> brains.de> wrote:
> >
> >
> >
> > On 12/03/18 20:02, Udit agarwal wrote:
> >
> > So, It looks like here's the final patch, do let me know if its ready to
> be pushed. Also, it would be really helpful if someone else also tests this
> patch before pushing(Although i have done that once).
> >
> > Thanks,
> > Udit agarwal
> >
> >
> > From 454a8ff3e0ea3393818859874705a54b098c6081 Mon Sep 17 00:00:00 2001
> >
> > From: Udit agarwal <dev.madaari at gmail.com <mailto:dev.madaari at gmail.com>
> >
> >
> > Date: Tue, 13 Mar 2018 00:20:28 +0530
> > Subject: [PATCH] Added Getentropy() support to beagle BSP
> >
> > ---
> > bsps/arm/include/libcpu/am335x.h | 37 ++++++-
> > c/src/lib/libbsp/arm/beagle/Makefile.am | 4 +-
> > .../libbsp/arm/beagle/getentropy/bbb_getentropy.c | 116
> +++++++++++++++++++++
> > 3 files changed, 155 insertions(+), 2 deletions(-)
> > create mode 100644 c/src/lib/libbsp/arm/beagle/
> getentropy/bbb_getentropy.c
> >
> > diff --git a/bsps/arm/include/libcpu/am335x.h b/bsps/arm/include/libcpu/
> am335x.h
> > index 367e97c..cedd637 100644
> > --- a/bsps/arm/include/libcpu/am335x.h
> > +++ b/bsps/arm/include/libcpu/am335x.h
> > @@ -14,11 +14,17 @@
> >
> > * Modified by Ben Gras <beng at shrike-systems.com <mailto:
> beng at shrike-systems.com>> to add lots
> >
> > * of beagleboard/beaglebone definitions, delete lpc32xx specific
> > * ones, and merge with some other header files.
> > + *
> >
> > + * Modified by Udit agarwal <dev.madaari at gmail.com <mailto:
> dev.madaari at gmail.com>> to add random
> >
> > + * number generating module definitions and TRNG register structure.
> > */
> >
> > #if !defined(_AM335X_H_)
> > #define _AM335X_H_
> >
> > +/* For TRNG register definition */
> > +#include <stdint.h>
> > +
> > /* Interrupt controller memory map */
> > #define OMAP3_DM37XX_INTR_BASE 0x48200000 /* INTCPS physical address */
> >
> > @@ -701,4 +707,33 @@
> > #define AM335X_CM_PER_OCPWP_L3_CLKSTCTRL_CLKACTIVITY_OCPWP_L4_GCLK
> (0x00000020u)
> > #define AM335X_I2C_INT_STOP_CONDITION AM335X_I2C_IRQSTATUS_BF
> >
> > -#endif
> > +/* TRNG Register */
> > +
> > +/* RNG base address */
> > +#define RNG_BASE 0x48310000
> > +/* RNG clock control */
> > +#define CM_PER_RNG_CLKCTRL (AM335X_CM_PER_ADDR | (9 << 4))
> > +/* rng module clock status bits */
> > +#define AM335X_CLK_RNG_BIT_MASK (0x30000)
> > +/* Offset from RNG base for output ready flag */
> > +#define RNG_STATUS_RDY (1u << 0)
> > +/* Offset from RNG base for FRO related error */
> > +#define RNG_STATUS_ERR (1u << 1)
> > +/* Offset from RNG base for clock status */
> > +#define RNG_STATUS_CLK (1u << 31)
> > +/* enable module */
> > +#define AM335X_RNG_ENABLE (1 << 10)
> > +
> > +/* TRNG register structure */
> > +struct bbb_trng_register
> > +{
> > + uint64_t output; /* 00 */
> > + uint32_t status; /* 08 */
> > + uint32_t irq_en; /* 0c */
> > + uint32_t status_clr; /* 10 */
> > + uint32_t control; /* 14 */
> > + uint32_t config; /* 18 */
> > +};
> > +typedef struct bbb_trng_register bbb_trng_register;
> >
> >
> > The bbb (Beagle Bone Black) is a particular board and the AM335X is a
> SoC family. This should be something like this
> >
> > typedef struct {
> > ...
> > } am335x_trng;
> >
> >
> >
> > +
> > +#endif
> > \ No newline at end of file
> >
> >
> >
> > Git thinks that files should have a newline at the end of the file.
> >
> >
> >
> > diff --git a/c/src/lib/libbsp/arm/beagle/Makefile.am
> b/c/src/lib/libbsp/arm/beagle/Makefile.am
> > index 8251660..5d5ade3 100644
> > --- a/c/src/lib/libbsp/arm/beagle/Makefile.am
> > +++ b/c/src/lib/libbsp/arm/beagle/Makefile.am
> > @@ -40,7 +40,6 @@ libbsp_a_LIBADD =
> >
> > # Shared
> > libbsp_a_SOURCES += ../../shared/bootcard.c
> > -libbsp_a_SOURCES += ../../shared/getentropy-cpucounter.c
> > libbsp_a_SOURCES += ../../shared/src/bsp-fdt.c
> > libbsp_a_SOURCES += ../../shared/bspclean.c
> > libbsp_a_SOURCES += ../../shared/bspgetworkarea.c
> > @@ -88,6 +87,9 @@ libbsp_a_SOURCES += gpio/bbb-gpio.c
> > #pwm
> > libbsp_a_SOURCES += pwm/pwm.c
> >
> > +#getentropy
> > +libbsp_a_SOURCES += getentropy/bbb_getentropy.c
> > +
> >
> >
> >
> > With the new BSP source structure
> >
> > https://devel.rtems.org/ticket/3285
> >
> > this new file could be also placed at
> >
> > bsps/arm/beagle/dev/getentropy.c
> >
> >
> >
> > Is this specific to the Beagle or the SoC? Or a combination? Earlier you
> said the structure was SoC specific?
> >
> >
> > [...]
> >
> > +int getentropy(void *ptr, size_t n)
> > +{
> > + volatile bbb_trng_register *rng = (bbb_trng_register*) RNG_BASE;
> > + am335x_rng_enable(rng);
> > + while (n > 0)
> > + {
> > + uint64_t random;
> > + size_t copy;
> > +
> > + /* wait untill RNG becomes ready with next set of random data */
> > + while( ( rng->status & RNG_STATUS_RDY ) == 0 )
> > + {
> > + /* wait */
> > + }
> >
> >
> > What happens if you call this function in parallel on different
> processors?
> >
> >
> > +
> > + random = trng_getranddata(rng);
> > +
> > + /* Checking for error by masking all bits other then error bit
> in
> > + status register */
> > + if( ((rng->status & RNG_STATUS_ERR)>>1) == 1)
> > + {
> > + /* clear the status flag after reading to generate new
> random
> > + value */
> > + rng->status_clr = RNG_STATUS_RDY;
> > + copy = sizeof(random);
> > + if ( n < copy )
> > + {
> > + copy = n;
> > + }
> > + memcpy(ptr, &random, copy);
> > + n -= copy;
> > + ptr = (char*)ptr + copy;
> > + }
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +RTEMS_SYSINIT_ITEM(
> > + am335x_rng_clock_enable,
> > + RTEMS_SYSINIT_DEVICE_DRIVERS,
> > + RTEMS_SYSINIT_ORDER_LAST
> > +);
> > \ No newline at end of file
> > --
> > 1.9.1
> >
> >
> >
> >
> >
> > _______________________________________________
> > devel mailing list
> > devel at rtems.org
> > http://lists.rtems.org/mailman/listinfo/devel
> >
> >
> > --
> > Sebastian Huber, embedded brains GmbH
> >
> > Address : Dornierstr. 4, D-82178 Puchheim, Germany
> > Phone : +49 89 189 47 41-16
> > Fax : +49 89 189 47 41-09
> > E-Mail : sebastian.huber at embedded-brains.de
> > PGP : Public key available on request.
> >
> > Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
> >
> >
> > _______________________________________________
> > devel mailing list
> > devel at rtems.org
> > http://lists.rtems.org/mailman/listinfo/devel
> >
> >
> >
> >
>
> --
> --------------------------------------------
> embedded brains GmbH
> Christian Mauderer
> Dornierstr. 4
> D-82178 Puchheim
> Germany
> email: christian.mauderer at embedded-brains.de
> Phone: +49-89-18 94 741 - 18
> Fax: +49-89-18 94 741 - 08
> PGP: Public key available on request.
>
> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
>
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