Fix NRF52 UART DMA and Renode test infrastructure

hal/nrf52.c:
- Use static volatile buffer for UARTE DMA source instead of stack
  variable address. GCC 15.2 with -Os optimized away the store to the
  stack slot, causing the DMA to read zeros.
- Set UART0_ENABLE to 4 (UARTE mode) per NRF52840 datasheet.

tools/test-expect-version/test-expect-version.c:
- Replace deprecated termio.h and linux/serial.h with sys/ioctl.h
  for compatibility with newer glibc.

tools/renode/docker-test.sh:
- Remove unused RENODE_CHECKOUT env var.

tools/scripts/renode-test-update.sh:
- Add robust UART wait functions with timeouts and liveness checks.
- Log Renode output to /tmp/renode.log for diagnostics on failure.
- Use run_expect_version helper with configurable timeout.

hal/nrf52.c

@@ -29,14 +29,16 @@
 void uart_init(void)
 {
     UART0_BAUDRATE = BAUD_115200;
-    UART0_ENABLE = 1;
+    UART0_ENABLE = 4;
 }
 
+static volatile uint8_t uart_tx_buf;
+
 static void uart_write_char(char c)
 {
+    uart_tx_buf = c;
     UART0_EVENT_ENDTX = 0;
-
-    UART0_TXD_PTR = (uint32_t)(&c);
+    UART0_TXD_PTR = (uint32_t)&uart_tx_buf;
     UART0_TXD_MAXCOUNT = 1;
     UART0_TASK_STARTTX = 1;
     while(UART0_EVENT_ENDTX == 0)

tools/renode/docker-test.sh

@@ -18,7 +18,6 @@ if ! docker run \
   --volume ${HOST_ROOT_DIR}:${DOCKER_WORKSPACE} \
   --volume ${HOST_TEST_RESULTS_PATH}:${DOCKER_TEST_RESULTS_PATH} \
   --env SCRIPT=${DOCKER_WORKSPACE}/renode-config.resc \
-  --env RENODE_CHECKOUT=/home/developer/renode \
   --workdir ${DOCKER_WORKSPACE} \
   ${DOCKER_IMAGE} \
   /bin/bash -c "tools/scripts/renode-test-update.sh $@ 2>&1 > ${DOCKER_TEST_RESULTS_PATH}/logs.txt"

tools/scripts/renode-test-update.sh

@@ -1,4 +1,5 @@
 #!/bin/bash
+set -u
 
 export RENODE_UART=/tmp/wolfboot.uart
 export RENODE_PIDFILE=/tmp/renode.pid
@@ -8,6 +9,18 @@ export RENODE_PORT=55155
 export RENODE_OPTIONS="--pid-file=$RENODE_PIDFILE --disable-xwt -P $RENODE_PORT"
 export EXPVER=tools/test-expect-version/test-expect-version
 export TEST_OPTIONS=$@
+export RENODE_START_TIMEOUT=30
+export UART_OPEN_TIMEOUT=10
+export EXPVER_TIMEOUT=75
+export RENODE_LOG=/tmp/renode.log
+RENODE_BG_PID=
+
+show_renode_log() {
+    if [ -f "$RENODE_LOG" ]; then
+        echo "----- Renode log -----"
+        tail -n 80 "$RENODE_LOG"
+    fi
+}
 
 quit_renode() {
     if (which nc); then
@@ -15,10 +28,72 @@ quit_renode() {
     fi
 }
 
+renode_is_alive() {
+    if [ -n "${RENODE_BG_PID:-}" ] && kill -0 "$RENODE_BG_PID" 2>/dev/null; then
+        return 0
+    fi
+    if [ -f "$RENODE_PIDFILE" ] && kill -0 "$(cat "$RENODE_PIDFILE")" 2>/dev/null; then
+        return 0
+    fi
+    return 1
+}
 
+wait_for_uart_node() {
+    local waited=0
 
+    while [ "$waited" -lt "$RENODE_START_TIMEOUT" ]; do
+        if [ -e "$RENODE_UART" ]; then
+            return 0
+        fi
+        if ! renode_is_alive; then
+            echo "Renode exited before creating UART PTY"
+            show_renode_log
+            return 1
+        fi
+        sleep 1
+        waited=$((waited + 1))
+    done
 
-rm -f $RENODE_UART
+    echo "Timed out waiting for Renode UART PTY: $RENODE_UART"
+    show_renode_log
+    return 1
+}
+
+wait_for_uart_ready() {
+    local waited=0
+
+    while [ "$waited" -lt "$UART_OPEN_TIMEOUT" ]; do
+        if bash -lc 'exec 3<>"$1"' _ "$RENODE_UART" 2>/dev/null; then
+            return 0
+        fi
+        if ! renode_is_alive; then
+            echo "Renode exited before UART became ready"
+            show_renode_log
+            return 1
+        fi
+        sleep 1
+        waited=$((waited + 1))
+    done
+
+    echo "Timed out waiting for Renode UART readiness: $RENODE_UART"
+    show_renode_log
+    return 1
+}
+
+run_expect_version() {
+    local expected="$1"
+    local ret
+
+    ret=$(timeout "$EXPVER_TIMEOUT" "$EXPVER" "$RENODE_UART")
+    if [ "$ret" = "$expected" ]; then
+        return 0
+    fi
+
+    echo "Unexpected version from UART: got ${ret}, expected ${expected}"
+    return 1
+}
+
+rm -f $RENODE_UART $RENODE_LOG
 
 make keysclean
 make keytools
@@ -31,13 +106,15 @@ cp wolfboot.elf /tmp/renode-wolfboot.elf || exit 3
 cp test-app/image_v1_signed.bin /tmp/renode-test-v1.bin || exit 3
 cp test-app/renode-test-update.bin /tmp || exit 3
 echo "Launching Renode"
-renode $RENODE_OPTIONS $RENODE_CONFIG >/dev/null &
-while ! (test -e $RENODE_UART); do sleep .1; done
+renode $RENODE_OPTIONS $RENODE_CONFIG >"$RENODE_LOG" 2>&1 &
+RENODE_BG_PID=$!
+wait_for_uart_node || { quit_renode; exit 1; }
 echo "Renode up: uart port activated"
+wait_for_uart_ready || { quit_renode; exit 1; }
+sleep 1
 echo "Renode running: renode has been started."
-RET=$($EXPVER $RENODE_UART)
 
-if (test $RET -eq 1); then
+if run_expect_version 1; then
     echo "Factory img: OK"
 else
     echo "FAILURE"
@@ -45,8 +122,7 @@ else
     exit 1
 fi
 
-RET=$($EXPVER $RENODE_UART)
-if (test $RET -eq 2); then
+if run_expect_version 2; then
     echo "Update: OK"
 else
     echo "FAILURE"

tools/test-expect-version/test-expect-version.c

@@ -41,8 +41,7 @@
 #include <errno.h>
 
 #ifndef __MACH__
-#include <termio.h>
-#include <linux/serial.h>
+#include <sys/ioctl.h>
 typedef void (*sighandler_t)(int);
 sighandler_t sigset(int sig, sighandler_t disp);
 #endif