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xiaoxiang pushed a commit to branch releases/12.12
in repository https://gitbox.apache.org/repos/asf/nuttx.git
The following commit(s) were added to refs/heads/releases/12.12 by this push:
new 4a032cb608d arch/arm/samv7: allow all values for count in read
4a032cb608d is described below
commit 4a032cb608d8ecdb4ff32b5810a843b7aec55985
Author: Mathias Duckeck <[email protected]>
AuthorDate: Wed Dec 3 08:07:37 2025 +0100
arch/arm/samv7: allow all values for count in read
The parameter count of read had to be a multiple of 4, otherwise the
result was truncated. Now all values are possible.
Signed-off-by: Mathias Duckeck <[email protected]>
---
arch/arm/src/samv7/sam_trng.c | 47 ++++++++++++++++++-------------------------
1 file changed, 20 insertions(+), 27 deletions(-)
diff --git a/arch/arm/src/samv7/sam_trng.c b/arch/arm/src/samv7/sam_trng.c
index adba73fe9d8..923414f430d 100644
--- a/arch/arm/src/samv7/sam_trng.c
+++ b/arch/arm/src/samv7/sam_trng.c
@@ -66,8 +66,9 @@ struct trng_dev_s
{
mutex_t lock; /* Enforces exclusive access to the TRNG */
sem_t waitsem; /* Wait for buffer full */
- uint32_t *samples; /* Current buffer being filled */
- size_t maxsamples; /* Size of the current buffer (in 32-bit words) */
+ uint32_t odata; /* last random value */
+ uint8_t *samples; /* Current buffer being filled */
+ size_t maxsamples; /* Size of the current buffer (in bytes) */
volatile size_t nsamples; /* Number of samples currently buffered */
volatile bool first; /* The first random number must be handled
differently */
};
@@ -145,14 +146,14 @@ static int sam_interrupt(int irq, void *context, void
*arg)
* number generator test).
*/
- if (g_trngdev.nsamples == 0)
+ if (g_trngdev.first)
{
/* This is the first sample we have taken. Save it for subsequent
* comparison.
*/
- g_trngdev.samples[0] = odata;
- g_trngdev.nsamples = 1;
+ g_trngdev.odata = odata;
+ g_trngdev.first = false;
continue;
}
@@ -160,7 +161,7 @@ static int sam_interrupt(int irq, void *context, void *arg)
* the preceding sample.
*/
- else if (odata == g_trngdev.samples[g_trngdev.nsamples - 1])
+ if (odata == g_trngdev.odata)
{
/* Two samples with the same value. Discard this one and try
* again.
@@ -169,33 +170,25 @@ static int sam_interrupt(int irq, void *context, void
*arg)
continue;
}
- /* This sample differs from the previous value. Have we discarded the
- * first sample yet?
- */
+ g_trngdev.odata = odata;
- if (g_trngdev.first)
+ /* Add the new random number to the buffer */
+
+ if (g_trngdev.nsamples + 4 <= g_trngdev.maxsamples)
{
- /* No, discard it now by replacing it with the new sample */
+ /* copy all 4 bytes */
- g_trngdev.samples[0] = odata;
- g_trngdev.nsamples = 1;
- g_trngdev.first = false;
+ *((uint32_t *)&g_trngdev.samples[g_trngdev.nsamples]) = odata;
+ g_trngdev.nsamples += 4;
}
-
- /* Yes.. the first sample has been discarded */
-
else
{
- /* Add the new random number to the buffer */
+ /* copy the remaining bytes */
- g_trngdev.samples[g_trngdev.nsamples] = odata;
- g_trngdev.nsamples++;
- }
+ memcpy(&g_trngdev.samples[g_trngdev.nsamples], &odata,
+ (g_trngdev.maxsamples - g_trngdev.nsamples));
+ g_trngdev.nsamples = g_trngdev.maxsamples;
- /* Have all of the requested samples been saved? */
-
- if (g_trngdev.nsamples == g_trngdev.maxsamples)
- {
/* Yes.. disable any further interrupts */
putreg32(TRNG_INT_DATRDY, SAM_TRNG_IDR);
@@ -249,7 +242,7 @@ static ssize_t sam_read(struct file *filep, char *buffer,
size_t buflen)
DEBUGASSERT(((uintptr_t)buffer & 3) == 0);
g_trngdev.samples = (uint32_t *)buffer;
- g_trngdev.maxsamples = buflen >> 2;
+ g_trngdev.maxsamples = buflen;
g_trngdev.nsamples = 0;
g_trngdev.first = true;
@@ -294,7 +287,7 @@ static ssize_t sam_read(struct file *filep, char *buffer,
size_t buflen)
/* Success... calculate the number of bytes to return */
- retval = g_trngdev.nsamples << 2;
+ retval = g_trngdev.nsamples;
errout:
