Hi,
I have updated the patch, following were the changes:
*Removed trialling white spaces and added new line at the end of each file
*am335x_rng_enable() is now being called only once during initialization.
*changed directory to /arm/beagle/dev/bbb_getentropy.c
*Renamed TRNG register structure as: am335x_trng_register
I have tested the patch after making above changes and it worked as before.
I need some suggestion regarding the solution to the problem raised during
parallel execution of getentropy(),
In that case, Two processes can actually fetch same random number. I was
thinking to implement some sort of
flag set/reset variable in shared memory, which can be used to implement a
lock for TRNG register access something
like a binary semaphore.
>From b10e55c7f5cc8ca95b0d9b6a8cc7b8e37330544b Mon Sep 17 00:00:00 2001
From: Udit agarwal <dev.mada...@gmail.com>
Date: Tue, 13 Mar 2018 15:50:43 +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 | 117
+++++++++++++++++++++++
3 files changed, 153 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 <b...@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.mada...@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..b2aea71
--- /dev/null
+++ b/c/src/lib/libbsp/arm/beagle/dev/bbb_getentropy.c
@@ -0,0 +1,117 @@
+/**
+* @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 <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)
+
+/* 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;
+
+ /* wait untill RNG becomes ready with next set of random data */
+ while( ( rng->status & RNG_STATUS_RDY ) == 0 )
+ {
+ /* wait */
+ }
+
+ 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
+);
--
1.9.1
Regards,
Udit
On Tue, Mar 13, 2018 at 12:01 PM, Sebastian Huber <
sebastian.hu...@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.mada...@gmail.com <mailto:dev.mada...@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/ge
>> tentropy/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 <b...@shrike-systems.com <mailto:
>> b...@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.mada...@gmail.com <mailto:
>> dev.mada...@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
>
> [...]
>> +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@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.hu...@embedded-brains.de
> PGP : Public key available on request.
>
> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
>
>
From b10e55c7f5cc8ca95b0d9b6a8cc7b8e37330544b Mon Sep 17 00:00:00 2001
From: Udit agarwal <dev.mada...@gmail.com>
Date: Tue, 13 Mar 2018 15:50:43 +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 | 117 +++++++++++++++++++++++
3 files changed, 153 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 <b...@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.mada...@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..b2aea71
--- /dev/null
+++ b/c/src/lib/libbsp/arm/beagle/dev/bbb_getentropy.c
@@ -0,0 +1,117 @@
+/**
+* @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 <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)
+
+/* 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;
+
+ /* wait untill RNG becomes ready with next set of random data */
+ while( ( rng->status & RNG_STATUS_RDY ) == 0 )
+ {
+ /* wait */
+ }
+
+ 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
+);
--
1.9.1
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