On 14/03/18 00:38, Udit agarwal wrote:
Hi,
@Joel This seems to be SoC specific.
Yes, it is an on-chip peripheral.
So, here is the implementation with mutex, Do let me know if this is
okay. I'll then do it for atsam also.
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");
In order to ensure mutual exclusion for a particular piece of code via a
mutex object all threads must use the same mutex object. Here, you
create a mutex object on the fly on the stack of the executing thread.
So, each thread has its own mutex. This doesn't work. You must use a
global mutex used by all threads. For example:
static rtems_mutex am335x_trng_mutex = RTEMS_MUTEX_INITIALIZER("AM335X
TRNG");
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);
I would do the lock/unlock around the while loop.
/* 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;
}
}
rtems_mutex_destroy(&lock_trng_reg);
return 0;
}
On Wed, Mar 14, 2018 at 2:15 AM, Joel Sherrill <j...@rtems.org
<mailto:j...@rtems.org>> wrote:
On Mar 13, 2018 1:31 AM, "Sebastian Huber"
<sebastian.hu...@embedded-brains.de
<mailto: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>
<mailto: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
<http://akefile.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 <b...@shrike-systems.com
<mailto:b...@shrike-systems.com>
<mailto: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>
<mailto: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
<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
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--
Sebastian Huber, embedded brains GmbH
Address : Dornierstr. 4, D-82178 Puchheim, Germany
<https://maps.google.com/?q=Dornierstr.+4,+D-82178+Puchheim,+Germany&entry=gmail&source=g>
Phone : +49 89 189 47 41-16 <tel:%2B49%2089%20189%2047%2041-16>
Fax : +49 89 189 47 41-09 <tel:%2B49%2089%20189%2047%2041-09>
E-Mail : sebastian.hu...@embedded-brains.de
<mailto:sebastian.hu...@embedded-brains.de>
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Diese Nachricht ist keine geschäftliche Mitteilung im Sinne
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--
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.
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