added mikrophone yocto layer; added esp32 driver;HEADmaster

11 files changed, 795 insertions, 7 deletions

diff --git a/yocto/README b/yocto/README
index ef99121..f170e18 100644
--- a/yocto/README
+++ b/yocto/README
@@ -18,7 +18,7 @@ apt-get install bc build-essential git libncurses5-dev lzop perl libssl-dev biso
 apt-get install u-boot-tools
 
 # dependencies for kernel:
- apt-get install bc build-essential git libncurses5-dev lzop perl libssl-dev bison flex
+apt-get install bc build-essential git libncurses5-dev lzop perl libssl-dev bison flex
 apt-get install u-boot-tools
 
 locale-gen en_US.UTF-8
@@ -76,11 +76,12 @@ yocto image
 - clone meta-information
 mkdir oe-core
 cd oe-core
-# branch: repo init -u git://git.toradex.com/toradex-manifest.git -b scarthgap-7.x.y -m tdxref/default.xml
+# branch: 
+repo init -u git://git.toradex.com/toradex-manifest.git -b scarthgap-7.x.y -m tdxref/default.xml
 # specific tag:
-repo init -u git://git.toradex.com/toradex-manifest.git -b refs/tags/7.1.0 -m tdxref/default.xml
+# repo init -u git://git.toradex.com/toradex-manifest.git -b refs/tags/7.1.0 -m tdxref/default.xml
 repo sync
-# repeat sync until successful
+# repeat repo sync until successful
 
 - setup environment:
 . export
@@ -90,17 +91,43 @@ vi conf/local.conf
 ...
 # set MACHINE:
 MACHINE ?= "verdin-imx8mp"
+...
+# set debian packages
+PACKAGE_CLASSES ?= "package_deb"
+...
 # append:
 ACCEPT_FSL_EULA = "1"
 TOOLCHAIN_TARGET_TASK:append = " kernel-devsrc"
+TOOLCHAIN_TARGET_TASK:remove = "target-sdk-provides-dummy"
+...
+
+- append mikrophone layer:
+vi conf/bblayers.conf
+# append to BBLAYERS variable:
 ...
+  ${TOPDIR}/../layers/meta-mikrophone \
+"
+
+# copy yocto/meta-mikrophone to ../layers/ dir from mikroPhone repo
 
 - build:
-bitbake -k tdx-reference-minimal-image -c populate_sdk
+# bitbake -k tdx-reference-minimal-image
+# bitbake -k tdx-reference-minimal-image -c populate_sdk
+bitbake -k mikrophone-image
+bitbake -k mikrophone-image -c populate_sdk
+
+- install sdk:
+deploy/sdk/tdx-xwayland-glibc-x86_64-mikroPhone-Image-armv8a-verdin-imx8mp-toolchain-7.x.y.sh
+# install into: /build/tdx-xwayland/7.x.y
 
 - machine.conf in: layers/meta-toradex-nxp/conf/machine/verdin-imx8mp.conf
-- distro.conf in: layers/meta-toradex-distro/conf/distro/*.conf
-- demo images in: layers/meta-toradex-demos/recipes-images/images/*.bb
+- mikrophone distro.conf in: layers/meta-mikrophone/conf/distro/*.conf
+- mikrophone images in: layers/meta-mikrophone/recipes-images/images/*.bb
+- deployable tarballs in: build/deploy/images/verdin-imx8mp/
+- deployable sdk in: build/deploy/sdk/
+
+- toradex distro.conf in: layers/meta-toradex-distro/conf/distro/*.conf
+- toradex demo images in: layers/meta-toradex-demos/recipes-images/images/*.bb
 
 u-boot
 ------
@@ -177,3 +204,46 @@ overlay
 cd overlays
 STAGING_KERNEL_DIR=../linux-toradex make mikroPhone-panel_overlay.dtbo
 cd ..
+
+
+esp32d
+------
+
+- setup environment:
+. /build/tdx-xwayland/7.x.y/environment-setup-armv8a-tdx-linux 
+
+- build:
+# copy yocto/esp32d from mikroPhone repo
+cd esp32d
+make
+cd ..
+
+
+debian repository
+-----------------
+
+- install aptly and configure aptly:
+apt-get install aptly gnupg1 gpgv1
+aptly	# creates config file
+vi ~/.aptly.conf
+...
+  "gpgProvider": "internal",
+...
+  "FileSystemPublishEndpoints": {
+    "mikrophone": {
+      "rootDir": "/build/repo",
+      "linkMethod": "copy",
+      "verifyMethod": "md5"
+    }
+  },
+...
+
+- generate gpg signing key:
+gpg1 --gen-key
+gpg1 --export --armor	# signing key for apt-key add
+
+- create and publish repository:
+aptly repo create -distribution=koshuta -component=main mikrophone
+aptly repo add mikrophone /build/oe-core/build/deploy/deb
+aptly publish repo mikrophone filesystem:mikrophone:
+aptly publish update koshuta filesystem:mikrophone:
diff --git a/yocto/esp32d/Makefile b/yocto/esp32d/Makefile
new file mode 100644
index 0000000..677d09d
--- /dev/null
+++ b/yocto/esp32d/Makefile
@@ -0,0 +1,15 @@
+#CFLAGS =
+LDFLAGS = -pthread -lgpiod
+TARGET = esp32d
+obj = msgq.o spi.o tun.o
+
+all: $(TARGET)
+
+%.o: %.c %.h
+	$(CC) $(CFLAGS) -c $<
+
+$(TARGET): $(obj)
+	$(CC) $(obj) $(LDFLAGS) -o $@
+
+clean:
+	rm -f $(TARGET) *.o
diff --git a/yocto/esp32d/msgq.c b/yocto/esp32d/msgq.c
new file mode 100644
index 0000000..3039f13
--- /dev/null
+++ b/yocto/esp32d/msgq.c
@@ -0,0 +1,43 @@
+#include <stdlib.h>
+#include <pthread.h>
+
+#include "msgq.h"
+
+#define IDX_MASK(IDX, SIZE)     ((IDX) & ((SIZE) - 1))
+
+int msgq_init(MSGQueue *msgq, unsigned char **array, uint16_t size) {
+    int rv;
+
+    msgq->idx_r = 0;
+    msgq->idx_w = 0;
+    msgq->size = size;
+    msgq->array = array;
+    rv = pthread_mutex_init(&msgq->mutex, NULL);
+    if (rv) {
+        return MSGQ_ERR;
+    }
+
+    rv = pthread_cond_init(&msgq->cond, NULL);
+    if (rv) {
+        pthread_mutex_destroy(&msgq->mutex);
+        return MSGQ_ERR;
+    }
+    return MSGQ_OK;
+}
+
+int msgq_push(MSGQueue *msgq, unsigned char *buffer) {
+    if ((uint16_t)(msgq->idx_w - msgq->idx_r) == msgq->size) return MSGQ_ERR_FULL;
+
+    msgq->array[IDX_MASK(msgq->idx_w++, msgq->size)] = buffer;
+    return MSGQ_OK;
+}
+
+unsigned char *msgq_pop(MSGQueue *msgq) {
+    if (msgq->idx_r == msgq->idx_w) return NULL;
+
+    return msgq->array[IDX_MASK(msgq->idx_r++, msgq->size)];
+}
+
+uint16_t msgq_len(MSGQueue *msgq) {
+    return (uint16_t)(msgq->idx_w - msgq->idx_r);
+}
diff --git a/yocto/esp32d/msgq.h b/yocto/esp32d/msgq.h
new file mode 100644
index 0000000..32b20d0
--- /dev/null
+++ b/yocto/esp32d/msgq.h
@@ -0,0 +1,22 @@
+#include <stdint.h>
+
+#define MSGQ_OK         0
+#define MSGQ_ERR        -1
+
+#define MSGQ_ERR_SIZE   -10
+#define MSGQ_ERR_FULL   -11
+#define MSGQ_ERR_EMPTY  -12
+
+typedef struct MSGQueue {
+    uint16_t idx_r;
+    uint16_t idx_w;
+    uint16_t size;
+    unsigned char **array;
+    pthread_mutex_t mutex;
+    pthread_cond_t cond;
+} MSGQueue;
+
+int msgq_init(MSGQueue *msgq, unsigned char **array, uint16_t size);
+int msgq_push(MSGQueue *msgq, unsigned char *buffer);
+unsigned char *msgq_pop(MSGQueue *msgq);
+uint16_t msgq_len(MSGQueue *msgq);
diff --git a/yocto/esp32d/spi.c b/yocto/esp32d/spi.c
new file mode 100644
index 0000000..db46a63
--- /dev/null
+++ b/yocto/esp32d/spi.c
@@ -0,0 +1,411 @@
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <assert.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+
+#include <linux/spi/spidev.h>
+
+#include <gpiod.h>
+#include <pthread.h>
+
+#include "msgq.h"
+#include "tun.h"
+#include "spi.h"
+
+static pthread_t worker_thd;
+static pthread_t rtscts_thd;
+static pthread_t msg_handler_thd;
+static pthread_t tun_handler_thd;
+static pthread_mutex_t mutex;
+static pthread_cond_t cond;
+
+static MSGQueue spi_bufq;
+static unsigned char *spi_bufq_array[SPI_SIZE_BUFQ];
+
+static MSGQueue spi_msgq_in;
+static unsigned char *spi_msgq_in_array[SPI_SIZE_MSGQ_IN];
+
+static MSGQueue spi_msgq_out;
+static unsigned char *spi_msgq_out_array[SPI_SIZE_MSGQ_OUT];
+
+static uint32_t spi_speed = SPI_SPEED;
+static int spi_fd;
+static volatile int spi_cts;
+
+struct gpiod_line_request *request = NULL;
+
+static void _spi_wait4cts(void) {
+    pthread_mutex_lock(&mutex);
+    while (!spi_cts) {
+        pthread_cond_wait(&cond, &mutex);
+    }
+    spi_cts = 0;
+    pthread_mutex_unlock(&mutex);
+}
+
+static int _spi_xchg(unsigned char *buffer) {
+    int rv;
+    uint16_t len_tx;
+    uint16_t len_rx;
+    struct spi_ioc_transfer tr;
+
+    memset(&tr, 0, sizeof(tr));
+    tr.tx_buf = (unsigned long)buffer;
+    tr.rx_buf = (unsigned long)buffer;
+    tr.speed_hz = spi_speed;
+
+    len_tx  = (uint16_t)buffer[1] << 8;
+    len_tx |= (uint16_t)buffer[2] & 0xFF;
+    if (len_tx > SPI_MTU) return SPI_ERR;
+
+    if (buffer[0]) {
+        len_tx += SPI_SIZE_HDR;
+        // esp32 dma workaraund
+        if (len_tx < 8) {
+            len_tx = 8;
+        } else if (len_tx % 4 != 0) {
+            len_tx = (len_tx / 4 + 1) * 4;
+        }
+
+        tr.len = len_tx;
+    } else {
+        /* nothing to send, reset esp32 spi transaction */
+        tr.len = 1;
+
+        _spi_wait4cts();
+        rv = ioctl(spi_fd, SPI_IOC_MESSAGE(1), &tr);
+        if (rv < 0) return SPI_ERR_MSG;
+
+        /* receive SPI_SIZE_RECEIVE bytes in first transaction (estimate) */
+        len_tx = SPI_SIZE_RECEIVE + SPI_SIZE_HDR;
+        tr.len = len_tx;
+        buffer[1] = 0;
+        buffer[2] = 0;
+    }
+
+    _spi_wait4cts();
+    rv = ioctl(spi_fd, SPI_IOC_MESSAGE(1), &tr);
+    if (rv < 0) return SPI_ERR_MSG;
+
+    len_rx  = (uint16_t)buffer[1] << 8;
+    len_rx |= (uint16_t)buffer[2] & 0xFF;
+    if (len_rx > SPI_MTU) return SPI_ERR;
+
+    len_rx += SPI_SIZE_HDR;
+    if (len_rx > len_tx) {
+        tr.tx_buf = (unsigned long)NULL;
+        tr.rx_buf = (unsigned long)(buffer + len_tx);
+
+        len_tx = len_rx - len_tx;
+        // esp32 dma workaraund
+        if (len_tx < 8) {
+            len_tx = 8;
+        } else if (len_tx % 4 != 0) {
+            len_tx = (len_tx / 4 + 1) * 4;
+        }
+
+        tr.len = len_tx;
+
+        _spi_wait4cts();
+        rv = ioctl(spi_fd, SPI_IOC_MESSAGE(1), &tr);
+        if (rv < 0) return SPI_ERR_MSG;
+    }
+
+    return SPI_OK;
+}
+
+static void *worker(void *arg) {
+    MSGQueue *bufq = &spi_bufq;
+    MSGQueue *msgq_in = &spi_msgq_in;
+    MSGQueue *msgq_out = &spi_msgq_out;
+    int rv;
+    unsigned char *buffer;
+
+    while (1) {
+        pthread_mutex_lock(&msgq_out->mutex);
+        buffer = msgq_pop(msgq_out);
+        if ((buffer == NULL) && (gpiod_line_request_get_value(request, SPI_GPIO_RTS) == GPIOD_LINE_VALUE_INACTIVE)) {
+            pthread_mutex_lock(&bufq->mutex);
+            buffer = msgq_pop(bufq);
+            pthread_mutex_unlock(&bufq->mutex);
+        }
+        if (buffer == NULL) {
+            pthread_cond_wait(&msgq_out->cond, &msgq_out->mutex);
+            buffer = msgq_pop(msgq_out);
+        }
+        pthread_mutex_unlock(&msgq_out->mutex);
+        if (buffer) {
+            rv = _spi_xchg(buffer);
+            if (rv || (buffer[0] == 0)) {
+                buffer[0] = 0;
+                buffer[1] = 0;
+                buffer[2] = 0;
+                pthread_mutex_lock(&bufq->mutex);
+                msgq_push(bufq, buffer);
+                pthread_mutex_unlock(&bufq->mutex);
+            } else {
+                pthread_mutex_lock(&msgq_in->mutex);
+                rv = msgq_push(msgq_in, buffer);
+                if (rv == MSGQ_OK) pthread_cond_signal(&msgq_in->cond);
+                pthread_mutex_unlock(&msgq_in->mutex);
+
+                if (rv) {
+                    pthread_mutex_lock(&bufq->mutex);
+                    msgq_push(bufq, buffer);
+                    pthread_mutex_unlock(&bufq->mutex);
+                }
+            }
+        }
+    }
+
+    return NULL;
+}
+
+static void *rtscts_handler(void *arg) {
+    MSGQueue *msgq_out = &spi_msgq_out;
+    struct gpiod_edge_event_buffer *event_buffer;
+    struct gpiod_edge_event *event;
+    int rv;
+
+    event_buffer = gpiod_edge_event_buffer_new(1);
+
+    while (1) {
+        rv = gpiod_line_request_read_edge_events(request, event_buffer, 1);
+        if (rv != 1) continue;
+
+        event = gpiod_edge_event_buffer_get_event(event_buffer, 0);
+        switch (gpiod_edge_event_get_line_offset(event)) {
+            case SPI_GPIO_RTS: {
+                pthread_mutex_lock(&msgq_out->mutex);
+                pthread_cond_signal(&msgq_out->cond);
+                pthread_mutex_unlock(&msgq_out->mutex);
+                break;
+            }
+
+            case SPI_GPIO_CTS: {
+                pthread_mutex_lock(&mutex);
+                spi_cts = 1;
+                pthread_cond_signal(&cond);
+                pthread_mutex_unlock(&mutex);
+                break;
+            }
+        }
+    }
+
+    gpiod_edge_event_buffer_free(event_buffer);
+    return NULL;
+}
+
+static void *msg_handler(void *arg) {
+    MSGQueue *bufq = &spi_bufq;
+    MSGQueue *msgq_in = &spi_msgq_in;
+    unsigned char *buffer;
+    unsigned char mtype;
+    uint16_t len;
+    int rv;
+
+    while (1) {
+        pthread_mutex_lock(&msgq_in->mutex);
+        buffer = msgq_pop(msgq_in);
+        if (buffer == NULL) {
+            pthread_cond_wait(&msgq_in->cond, &msgq_in->mutex);
+            buffer = msgq_pop(msgq_in);
+        }
+        pthread_mutex_unlock(&msgq_in->mutex);
+        if (buffer) {
+            mtype = buffer[0];
+            len  = (uint16_t)buffer[1] << 8;
+            len |= (uint16_t)buffer[2] & 0xFF;
+
+            switch (mtype) {
+                case SPI_MTYPE_TUN:
+                    tun_write(buffer + SPI_SIZE_HDR, len);
+                    break;
+            }
+            buffer[0] = 0;
+            buffer[1] = 0;
+            buffer[2] = 0;
+            pthread_mutex_lock(&bufq->mutex);
+            msgq_push(bufq, buffer);
+            pthread_mutex_unlock(&bufq->mutex);
+        }
+    }
+
+    return NULL;
+}
+
+static void *tun_handler(void *arg) {
+    unsigned char *buffer;
+    ssize_t len;
+
+    while (1) {
+        buffer = spi_alloc();
+        if (buffer == NULL) continue;
+
+        len = tun_read(buffer + SPI_SIZE_HDR, SPI_SIZE_BUF - SPI_SIZE_HDR);
+        if (len < 0) {
+            perror("tun read");
+            continue;
+        }
+        spi_xchg(SPI_MTYPE_TUN, buffer, len);
+    }
+
+    return NULL;
+}
+
+unsigned char *spi_alloc(void) {
+    MSGQueue *bufq = &spi_bufq;
+    unsigned char *buffer;
+
+    pthread_mutex_lock(&bufq->mutex);
+    buffer = msgq_pop(bufq);
+    pthread_mutex_unlock(&bufq->mutex);
+
+    return buffer;
+}
+
+void spi_free(unsigned char *buffer) {
+    MSGQueue *bufq = &spi_bufq;
+
+    buffer[0] = 0;
+    buffer[1] = 0;
+    buffer[2] = 0;
+    pthread_mutex_lock(&bufq->mutex);
+    msgq_push(bufq, buffer);
+    pthread_mutex_unlock(&bufq->mutex);
+}
+
+int spi_xchg(unsigned char mtype, unsigned char *buffer, uint16_t len) {
+    MSGQueue *bufq = &spi_bufq;
+    MSGQueue *msgq_out = &spi_msgq_out;
+    int rv;
+
+    buffer[0] = mtype;
+    buffer[1] = len >> 8;
+    buffer[2] = len & 0xFF;
+
+    pthread_mutex_lock(&msgq_out->mutex);
+    rv = msgq_push(msgq_out, buffer);
+    if (rv == MSGQ_OK) pthread_cond_signal(&msgq_out->cond);
+    pthread_mutex_unlock(&msgq_out->mutex);
+
+    if (rv) {
+        pthread_mutex_lock(&bufq->mutex);
+        msgq_push(bufq, buffer);
+        pthread_mutex_unlock(&bufq->mutex);
+    }
+
+    return rv;
+}
+
+int gpio_init(void) {
+    struct gpiod_chip *chip = NULL;
+    struct gpiod_line_settings *line_settings = NULL;
+    struct gpiod_line_config *line_cfg = NULL;
+    struct gpiod_request_config *req_cfg = NULL;
+    int rv;
+
+    unsigned int line_offsets[2] = { SPI_GPIO_RTS, SPI_GPIO_CTS };
+
+    chip = gpiod_chip_open(SPI_GPIO_DEV);
+    if (chip == NULL) goto gpio_init_fin;
+
+    line_settings = gpiod_line_settings_new();
+    if (line_settings == NULL) goto gpio_init_fin;
+
+    gpiod_line_settings_set_direction(line_settings, GPIOD_LINE_DIRECTION_INPUT);
+    gpiod_line_settings_set_edge_detection(line_settings, GPIOD_LINE_EDGE_FALLING);
+    gpiod_line_settings_set_bias(line_settings, GPIOD_LINE_BIAS_PULL_UP);
+
+    line_cfg = gpiod_line_config_new();
+    if (line_cfg == NULL) goto gpio_init_fin;
+
+    rv = gpiod_line_config_add_line_settings(line_cfg, line_offsets, 2, line_settings);
+    if (rv) goto gpio_init_fin;
+
+    req_cfg = gpiod_request_config_new();
+    if (req_cfg == NULL) goto gpio_init_fin;
+
+    gpiod_request_config_set_consumer(req_cfg, "rts-cts");
+
+    request = gpiod_chip_request_lines(chip, req_cfg, line_cfg);
+
+gpio_init_fin:
+    rv = (request ? SPI_OK : (chip ? SPI_ERR : SPI_ERR_OPEN));
+
+    if (req_cfg) gpiod_request_config_free(req_cfg);
+    if (line_cfg) gpiod_line_config_free(line_cfg);
+    if (line_settings) gpiod_line_settings_free(line_settings);
+    if (chip) gpiod_chip_close(chip);
+
+    return rv;
+}
+
+int spi_init(void) {
+    unsigned char *buffer;
+    int rv, i;
+
+    spi_fd = open(SPI_DEV, O_RDWR);
+    if (spi_fd < 0) return SPI_ERR_OPEN;
+
+    rv = ioctl(spi_fd, SPI_IOC_WR_MAX_SPEED_HZ, &spi_speed);
+    if (rv == -1) return SPI_ERR;
+
+    rv = msgq_init(&spi_bufq, spi_bufq_array, SPI_SIZE_BUFQ);
+    assert(rv == MSGQ_OK);
+
+    rv = msgq_init(&spi_msgq_in, spi_msgq_in_array, SPI_SIZE_MSGQ_IN);
+    assert(rv == MSGQ_OK);
+
+    rv = msgq_init(&spi_msgq_out, spi_msgq_out_array, SPI_SIZE_MSGQ_OUT);
+    assert(rv == MSGQ_OK);
+
+    for (i=0; i<SPI_SIZE_BUFQ; i++) {
+        buffer = malloc(SPI_SIZE_BUF);
+        assert(buffer);
+        msgq_push(&spi_bufq, buffer);
+    }
+
+    rv = pthread_mutex_init(&mutex, NULL);
+    assert(rv == 0);
+
+    rv = pthread_cond_init(&cond, NULL);
+    assert(rv == 0);
+
+    /* assret initial contitions */
+    pthread_mutex_lock(&mutex);
+    spi_cts = (gpiod_line_request_get_value(request, SPI_GPIO_CTS) == GPIOD_LINE_VALUE_INACTIVE);
+    pthread_mutex_unlock(&mutex);
+
+    rv = pthread_create(&worker_thd, NULL, worker, NULL);
+    assert(rv == 0);
+
+    rv = pthread_create(&rtscts_thd, NULL, rtscts_handler, NULL);
+    assert(rv == 0);
+
+    rv = pthread_create(&msg_handler_thd, NULL, msg_handler, NULL);
+    assert(rv == 0);
+
+    rv = pthread_create(&tun_handler_thd, NULL, tun_handler, NULL);
+    assert(rv == 0);
+
+    return SPI_OK;
+}
+
+int main(int argc, char *argv[]) {
+    int rv;
+
+    rv = tun_init(SPI_TUN_NAME);
+    if (rv) printf("TUN INIT ERR\n");
+
+    rv = gpio_init();
+    if (rv) printf("GPIO INIT ERR\n");
+
+    rv = spi_init();
+    if (rv) printf("SPI INIT ERR\n");
+
+    while (1);
+}
diff --git a/yocto/esp32d/spi.h b/yocto/esp32d/spi.h
new file mode 100644
index 0000000..4d9ff86
--- /dev/null
+++ b/yocto/esp32d/spi.h
@@ -0,0 +1,31 @@
+#include <stdint.h>
+
+#define SPI_DEV             "/dev/spidev0"
+#define SPI_SPEED           10000000
+
+#define SPI_TUN_NAME        "tun0"
+
+#define SPI_GPIO_DEV        "/dev/gpiochip3"
+#define SPI_GPIO_CTS        28
+#define SPI_GPIO_RTS        25
+
+#define SPI_MTU             1500
+#define SPI_SIZE_HDR        3
+#define SPI_SIZE_BUF        (SPI_MTU + SPI_SIZE_HDR)
+#define SPI_SIZE_RECEIVE    16  /* guestimate on number of bytes for transaction initiated by falling RTS */
+
+#define SPI_SIZE_BUFQ       64
+#define SPI_SIZE_MSGQ_IN    32
+#define SPI_SIZE_MSGQ_OUT   32
+
+#define SPI_MTYPE_TUN       1
+
+#define SPI_OK              0
+#define SPI_ERR             -1
+#define SPI_ERR_OPEN        -10
+#define SPI_ERR_MSG         -11
+
+unsigned char *spi_alloc(void);
+void spi_free(unsigned char *buffer);
+int spi_xchg(unsigned char mtype, unsigned char *buffer, uint16_t len);
+int spi_init(void);
\ No newline at end of file
diff --git a/yocto/esp32d/tun.c b/yocto/esp32d/tun.c
new file mode 100644
index 0000000..75043a3
--- /dev/null
+++ b/yocto/esp32d/tun.c
@@ -0,0 +1,84 @@
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+
+#include <linux/if.h>
+#include <linux/if_tun.h>
+
+#include <pthread.h>
+
+#include "spi.h"
+#include "tun.h"
+
+static pthread_t read_thd;
+
+static int tun_fd;
+static char tun_name[IFNAMSIZ];
+
+static int tun_alloc(char *dev, int flags) {
+    struct ifreq ifr;
+    int fd, err;
+    char *clonedev = "/dev/net/tun";
+
+    /* Arguments taken by the function:
+     *
+     * char *dev: the name of an interface (or '\0'). MUST have enough
+     *   space to hold the interface name if '\0' is passed
+     * int flags: interface flags (eg, IFF_TUN etc.)
+     */
+
+    fd = open(clonedev, O_RDWR);
+    if (fd < 0) {
+        return fd;
+    }
+
+    memset(&ifr, 0, sizeof(ifr));
+    ifr.ifr_flags = flags;  /* IFF_TUN or IFF_TAP, plus maybe IFF_NO_PI */
+
+    if (*dev) {
+        /* if a device name was specified, put it in the structure; otherwise,
+         * the kernel will try to allocate the "next" device of the
+         * specified type */
+        strncpy(ifr.ifr_name, dev, IFNAMSIZ);
+    }
+
+    /* try to create the device */
+    err = ioctl(fd, TUNSETIFF, (void *) &ifr);
+    if (err < 0) {
+        close(fd);
+        return err;
+    }
+
+    /* if the operation was successful, write back the name of the
+     * interface to the variable "dev", so the caller can know
+     * it. Note that the caller MUST reserve space in *dev (see calling
+     * code below) */
+    strcpy(dev, ifr.ifr_name);
+
+    /* this is the special file descriptor that the caller will use to talk
+     * with the virtual interface */
+    return fd;
+}
+
+ssize_t tun_read(unsigned char *buffer, size_t buf_size) {
+    return read(tun_fd, buffer, buf_size);
+}
+
+ssize_t tun_write(unsigned char *buffer, size_t buf_len) {
+    return write(tun_fd, buffer, buf_len);
+}
+
+int tun_init(char *name) {
+    int rv;
+
+    if (strlen(name) >= sizeof(tun_name) - 1) return -1;
+    strcpy(tun_name, name);
+
+    tun_fd = tun_alloc(tun_name, IFF_TUN | IFF_NO_PI);
+    if (tun_fd < 0) return -1;
+
+    return 0;
+}
diff --git a/yocto/esp32d/tun.h b/yocto/esp32d/tun.h
new file mode 100644
index 0000000..793a4c9
--- /dev/null
+++ b/yocto/esp32d/tun.h
@@ -0,0 +1,5 @@
+#include <sys/types.h>
+
+ssize_t tun_read(unsigned char *buffer, size_t buf_size);
+ssize_t tun_write(unsigned char *buffer, size_t buf_len);
+int tun_init(char *name);
\ No newline at end of file
diff --git a/yocto/meta-mikrophone/conf/distro/mikrophone.conf b/yocto/meta-mikrophone/conf/distro/mikrophone.conf
new file mode 100644
index 0000000..efeba6e
--- /dev/null
+++ b/yocto/meta-mikrophone/conf/distro/mikrophone.conf
@@ -0,0 +1,20 @@
+# Toradex Distro for Wayland with XWayland.
+# Using the downstream kernel flavour.
+
+require conf/distro/include/tdx-base.inc
+
+DISTRO = "mikrophone"
+DISTRO_NAME = "mikroPhone distribution"
+DISTRO_FLAVOUR = ""
+
+IMX_DEFAULT_BSP = "nxp"
+
+# we use graphics, so set opengl
+DISTRO_FEATURES:append = " opengl"
+
+DISTRO_FEATURES:append = " wayland x11"
+
+# lxqt requires this
+DISTRO_FEATURES:append = " polkit"
+TASK_BASIC_SSHDAEMON = "openssh-sshd openssh-sftp openssh-sftp-server"
+IMAGE_FEATURES:append = " ssh-server-openssh"
diff --git a/yocto/meta-mikrophone/conf/layer.conf b/yocto/meta-mikrophone/conf/layer.conf
new file mode 100644
index 0000000..8abd100
--- /dev/null
+++ b/yocto/meta-mikrophone/conf/layer.conf
@@ -0,0 +1,13 @@
+# We have a conf and classes directory, add to BBPATH
+BBPATH .= ":${LAYERDIR}"
+
+# We have recipes-* directories, add to BBFILES
+BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \
+            ${LAYERDIR}/recipes-*/*/*.bbappend"
+
+BBFILE_COLLECTIONS += "meta-mikrophone"
+BBFILE_PATTERN_meta-mikrophone = "^${LAYERDIR}/"
+BBFILE_PRIORITY_meta-mikrophone = "6"
+
+LAYERDEPENDS_meta-mikrophone = "core"
+LAYERSERIES_COMPAT_meta-mikrophone = "scarthgap"
diff --git a/yocto/meta-mikrophone/recipes-images/images/mikrophone-image.bb b/yocto/meta-mikrophone/recipes-images/images/mikrophone-image.bb
new file mode 100644
index 0000000..a4ced94
--- /dev/null
+++ b/yocto/meta-mikrophone/recipes-images/images/mikrophone-image.bb
@@ -0,0 +1,74 @@
+inherit core-image
+
+SUMMARY = "mikroPhone image"
+DESCRIPTION = "mikroPhone image"
+
+LICENSE = "MIT"
+
+#Prefix to the resulting deployable tarball name
+export IMAGE_BASENAME = "mikroPhone-Image"
+MACHINE_NAME ?= "${MACHINE}"
+IMAGE_NAME = "${MACHINE_NAME}_${IMAGE_BASENAME}"
+
+IMAGE_FEATURES += " \
+    ${@bb.utils.contains('DISTRO_FEATURES', 'wayland', 'weston', '', d)} \
+"
+
+# Copy Licenses to image /usr/share/common-license
+COPY_LIC_MANIFEST ?= "1"
+COPY_LIC_DIRS ?= "1"
+
+add_rootfs_version () {
+    printf "${DISTRO_NAME} ${DISTRO_VERSION} (${DISTRO_CODENAME}) \\\n \\\l\n" > ${IMAGE_ROOTFS}/etc/issue
+    printf "${DISTRO_NAME} ${DISTRO_VERSION} (${DISTRO_CODENAME}) %%h\n" > ${IMAGE_ROOTFS}/etc/issue.net
+    printf "${IMAGE_NAME}\n\n" >> ${IMAGE_ROOTFS}/etc/issue
+    printf "${IMAGE_NAME}\n\n" >> ${IMAGE_ROOTFS}/etc/issue.net
+}
+
+add_home_root_symlink () {
+    ln -sf ${ROOT_HOME} ${IMAGE_ROOTFS}/home/root
+}
+
+# add the rootfs version to the welcome banner
+ROOTFS_POSTPROCESS_COMMAND += " add_rootfs_version; add_home_root_symlink;"
+
+IMAGE_LINGUAS = "en-us"
+#IMAGE_LINGUAS = "de-de fr-fr en-gb en-us pt-br es-es kn-in ml-in ta-in"
+
+CONMANPKGS ?= "connman connman-plugin-loopback connman-plugin-ethernet connman-plugin-wifi connman-client"
+
+IMAGE_INSTALL += " \
+    packagegroup-boot \
+    packagegroup-basic \
+    packagegroup-base-tdx-cli \
+    packagegroup-machine-tdx-cli \
+    packagegroup-wifi-tdx-cli \
+    packagegroup-wifi-fw-tdx-cli \
+    udev-extraconf \
+    ${CONMANPKGS} \
+    ${@bb.utils.contains('DISTRO_FEATURES', 'systemd', \
+                         'timestamp-service systemd-analyze', '', d)} \
+    ${@bb.utils.contains('DISTRO_FEATURES', 'x11 wayland', \
+                         'weston-xwayland xterm', '', d)} \
+    ${@bb.utils.contains("MACHINE_FEATURES", "tpm2", \
+                         "packagegroup-tpm2-tdx-cli", "",d)} \
+    \
+    packagegroup-tdx-cli \
+    packagegroup-tdx-graphical \
+    packagegroup-fsl-isp \
+    \
+    bash \
+    coreutils \
+    less \
+    makedevs \
+    mime-support \
+    net-tools \
+    util-linux \
+    v4l-utils \
+    \
+    gpicview \
+    media-files \
+    \
+    gnupg \
+    weston weston-init wayland-terminal-launch \ 
+"