utils/hwstub: completely rework the protocol, drop unused features

The protocol has evolved a lot during the 2.x.y lifetime, bringing more
features which later got unused. This commit removes all the unused stuff
and simplifies everything:
- drop the feature mask: everything is mandatory or stalled on error
- remove the info request and put all static information in standard USB
  descriptors which are part of the configuration descriptor (and can be
  retrieved using the standard GetDescriptor request).
- remove the USB interface, we had only one anyway
- remove all endpoint descriptors
- remove the exit/atexit stuff, it never worked as intended anyway
- update the hwstub library and make it able to handle any device
- update the tools (mostly renaming and removing of code)

Change-Id: I1872bba7f4177fc3891180e8f944aab88f5bde31

4 files changed, 124 insertions, 321 deletions

diff --git a/utils/hwstub/stub/main.c b/utils/hwstub/stub/main.c
index 0923bf85ce..37590e88f8 100644
--- a/utils/hwstub/stub/main.c
+++ b/utils/hwstub/stub/main.c
@@ -51,16 +51,16 @@ static struct usb_device_descriptor __attribute__((aligned(2)))
     .bLength            = sizeof(struct usb_device_descriptor),
     .bDescriptorType    = USB_DT_DEVICE,
     .bcdUSB             = 0x0200,
-    .bDeviceClass       = USB_CLASS_PER_INTERFACE,
-    .bDeviceSubClass    = 0,
-    .bDeviceProtocol    = 0,
+    .bDeviceClass       = HWSTUB_CLASS,
+    .bDeviceSubClass    = HWSTUB_SUBCLASS,
+    .bDeviceProtocol    = HWSTUB_PROTOCOL,
     .bMaxPacketSize0    = 64,
     .idVendor           = HWSTUB_USB_VID,
     .idProduct          = HWSTUB_USB_PID,
     .bcdDevice          = HWSTUB_VERSION_MAJOR << 8 | HWSTUB_VERSION_MINOR,
     .iManufacturer      = 1,
     .iProduct           = 2,
-    .iSerialNumber      = 3,
+    .iSerialNumber      = 0,
     .bNumConfigurations = 1
 };
 
@@ -72,40 +72,13 @@ static struct usb_config_descriptor __attribute__((aligned(2)))
     .bLength             = sizeof(struct usb_config_descriptor),
     .bDescriptorType     = USB_DT_CONFIG,
     .wTotalLength        = 0, /* will be filled in later */
-    .bNumInterfaces      = 1,
+    .bNumInterfaces      = 0,
     .bConfigurationValue = 1,
     .iConfiguration      = 0,
     .bmAttributes        = USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
     .bMaxPower           = (USB_MAX_CURRENT + 1) / 2, /* In 2mA units */
 };
 
-/* main interface */
-static struct usb_interface_descriptor __attribute__((aligned(2)))
-    interface_descriptor =
-{
-    .bLength            = sizeof(struct usb_interface_descriptor),
-    .bDescriptorType    = USB_DT_INTERFACE,
-    .bInterfaceNumber   = 0,
-    .bAlternateSetting  = 0,
-    .bNumEndpoints      = 3,
-    .bInterfaceClass    = HWSTUB_CLASS,
-    .bInterfaceSubClass = HWSTUB_SUBCLASS,
-    .bInterfaceProtocol = HWSTUB_PROTOCOL,
-    .iInterface         = 4
-};
-
-
-static struct usb_endpoint_descriptor __attribute__((aligned(2)))
-    endpoint_descriptor =
-{
-    .bLength          = sizeof(struct usb_endpoint_descriptor),
-    .bDescriptorType  = USB_DT_ENDPOINT,
-    .bEndpointAddress = 0,
-    .bmAttributes     = USB_ENDPOINT_XFER_BULK,
-    .wMaxPacketSize   = 0,
-    .bInterval        = 0
-};
-
 static const struct usb_string_descriptor __attribute__((aligned(2)))
     usb_string_iManufacturer =
 {
@@ -117,42 +90,38 @@ static const struct usb_string_descriptor __attribute__((aligned(2)))
 static const struct usb_string_descriptor __attribute__((aligned(2)))
     usb_string_iProduct =
 {
-    52,
+    44,
     USB_DT_STRING,
     {'R', 'o', 'c', 'k', 'b', 'o', 'x', ' ',
      'h', 'a', 'r', 'd', 'w', 'a', 'r', 'e', ' ',
-     'e', 'm', 'u', 'l', 'a', 't', 'e', 'r'}
+     's', 't', 'u', 'b'}
 };
 
-static struct usb_string_descriptor __attribute__((aligned(2)))
-    usb_string_iSerial =
+/* this is stringid #0: languages supported */
+static const struct usb_string_descriptor __attribute__((aligned(2)))
+    lang_descriptor =
 {
-    84,
+    4,
     USB_DT_STRING,
-    {'0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0',
-     '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0',
-     '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0',
-     '0', '0', '0', '0', '0', '0', '0', '0'}
+    {0x0409} /* LANGID US English */
 };
 
-static struct usb_string_descriptor __attribute__((aligned(2)))
-    usb_string_iInterface =
+static struct hwstub_version_desc_t __attribute__((aligned(2)))
+    version_descriptor =
 {
-    28,
-    USB_DT_STRING,
-    {'A', 'c', 'i', 'd', ' ',
-     '0' + (HWSTUB_VERSION_MAJOR >> 4), '0' + (HWSTUB_VERSION_MAJOR & 0xf), '.',
-     '0' + (HWSTUB_VERSION_MINOR >> 4), '0' + (HWSTUB_VERSION_MINOR & 0xf), '.',
-     '0' + (HWSTUB_VERSION_REV >> 4), '0' + (HWSTUB_VERSION_REV & 0xf) }
+    sizeof(struct hwstub_version_desc_t),
+    HWSTUB_DT_VERSION,
+    HWSTUB_VERSION_MAJOR,
+    HWSTUB_VERSION_MINOR,
+    HWSTUB_VERSION_REV
 };
 
-/* this is stringid #0: languages supported */
-static const struct usb_string_descriptor __attribute__((aligned(2)))
-    lang_descriptor =
+static struct hwstub_layout_desc_t __attribute__((aligned(2)))
+    layout_descriptor =
 {
-    4,
-    USB_DT_STRING,
-    {0x0409} /* LANGID US English */
+    sizeof(struct hwstub_layout_desc_t),
+    HWSTUB_DT_LAYOUT,
+    0, 0, 0, 0, 0, 0
 };
 
 #define USB_NUM_STRINGS 5
@@ -162,26 +131,25 @@ static const struct usb_string_descriptor* const usb_strings[USB_NUM_STRINGS] =
    &lang_descriptor,
    &usb_string_iManufacturer,
    &usb_string_iProduct,
-   &usb_string_iSerial,
-   &usb_string_iInterface
 };
 
 uint8_t *usb_buffer = oc_bufferstart;
 uint32_t usb_buffer_size = 0;
 
-#define EP_BULK 1
-#define EP_INT  2
-
-static void set_config(void)
+static void fill_layout_info(void)
 {
-    usb_drv_configure_endpoint(EP_BULK, USB_ENDPOINT_XFER_BULK);
-    usb_drv_configure_endpoint(EP_INT, USB_ENDPOINT_XFER_INT);
+    layout_descriptor.dCodeStart = (uint32_t)oc_codestart;
+    layout_descriptor.dCodeSize = oc_codesize;
+    layout_descriptor.dStackStart = (uint32_t)oc_stackstart;
+    layout_descriptor.dStackSize = oc_stacksize;
+    layout_descriptor.dBufferStart = (uint32_t)oc_bufferstart;
+    layout_descriptor.dBufferSize = oc_buffersize;
 }
 
 static void handle_std_dev_desc(struct usb_ctrlrequest *req)
 {
     int size;
-    const void* ptr = NULL;
+    void* ptr = NULL;
     unsigned index = req->wValue & 0xff;
 
     switch(req->wValue >> 8)
@@ -208,32 +176,22 @@ static void handle_std_dev_desc(struct usb_ctrlrequest *req)
             }
             size = sizeof(struct usb_config_descriptor);
 
-            /* interface */
-            memcpy(usb_buffer + size, (void *)&interface_descriptor,
-                sizeof(interface_descriptor));
-            size += sizeof(interface_descriptor);
-            /* endpoint 1: bulk out */
-            endpoint_descriptor.bEndpointAddress = EP_BULK | USB_DIR_OUT;
-            endpoint_descriptor.bmAttributes = USB_ENDPOINT_XFER_BULK;
-            endpoint_descriptor.wMaxPacketSize = 512;
-            memcpy(usb_buffer + size, (void *)&endpoint_descriptor,
-                sizeof(endpoint_descriptor));
-            size += sizeof(endpoint_descriptor);
-            /* endpoint 2: bulk in */
-            endpoint_descriptor.bEndpointAddress = EP_BULK | USB_DIR_IN;
-            endpoint_descriptor.bmAttributes = USB_ENDPOINT_XFER_BULK;
-            endpoint_descriptor.wMaxPacketSize = 512;
-            memcpy(usb_buffer + size, (void *)&endpoint_descriptor,
-                sizeof(endpoint_descriptor));
-            size += sizeof(endpoint_descriptor);
-            /* endpoint 3: int in */
-            endpoint_descriptor.bEndpointAddress = EP_INT | USB_DIR_IN;
-            endpoint_descriptor.bmAttributes = USB_ENDPOINT_XFER_INT;
-            endpoint_descriptor.wMaxPacketSize = 1024;
-            memcpy(usb_buffer + size, (void *)&endpoint_descriptor,
-                sizeof(endpoint_descriptor));
-            size += sizeof(endpoint_descriptor);
-
+            /* hwstub version */
+            memcpy(usb_buffer + size, (void *)&version_descriptor,
+                sizeof(version_descriptor));
+            size += sizeof(version_descriptor);
+            /* hwstub layout */
+            fill_layout_info();
+            memcpy(usb_buffer + size, (void *)&layout_descriptor,
+                sizeof(layout_descriptor));
+            size += sizeof(layout_descriptor);
+            /* hwstub target */
+            fill_layout_info();
+            memcpy(usb_buffer + size, (void *)&target_descriptor,
+                sizeof(target_descriptor));
+            size += sizeof(target_descriptor);
+            /* target specific descriptors */
+            target_get_config_desc(usb_buffer + size, &size);
             /* fix config descriptor */
             config_descriptor.bNumInterfaces = 1;
             config_descriptor.wTotalLength = size;
@@ -246,12 +204,27 @@ static void handle_std_dev_desc(struct usb_ctrlrequest *req)
             if(index < USB_NUM_STRINGS)
             {
                 size = usb_strings[index]->bLength;
-                ptr = usb_strings[index];
+                ptr = (void *)usb_strings[index];
             }
             else
                 usb_drv_stall(EP_CONTROL, true, true);
             break;
+        case HWSTUB_DT_VERSION:
+            ptr = &version_descriptor;
+            size = sizeof(version_descriptor);
+            break;
+        case HWSTUB_DT_LAYOUT:
+            ptr = &layout_descriptor;
+            size = sizeof(layout_descriptor);
+            break;
+        case HWSTUB_DT_TARGET:
+            ptr = &target_descriptor;
+            size = sizeof(target_descriptor);
+            break;
         default:
+            target_get_desc(req->wValue >> 8, &ptr);
+            if(ptr != 0)
+                size = ((struct usb_descriptor_header *)ptr)->bLength;
             break;
     }
 
@@ -280,7 +253,6 @@ static void handle_std_dev_req(struct usb_ctrlrequest *req)
             break;
         case USB_REQ_SET_CONFIGURATION:
             usb_drv_send(EP_CONTROL, NULL, 0);
-            set_config();
             break;
         case USB_REQ_GET_DESCRIPTOR:
             handle_std_dev_desc(req);
@@ -311,67 +283,6 @@ static void handle_std_req(struct usb_ctrlrequest *req)
     }
 }
 
-struct usb_resp_info_version_t g_version =
-{
-    .major = HWSTUB_VERSION_MAJOR,
-    .minor = HWSTUB_VERSION_MINOR,
-    .revision = HWSTUB_VERSION_REV
-};
-
-struct usb_resp_info_layout_t g_layout;
-
-struct usb_resp_info_features_t g_features =
-{
-    .feature_mask = HWSTUB_FEATURE_LOG | HWSTUB_FEATURE_MEM |
-        HWSTUB_FEATURE_CALL | HWSTUB_FEATURE_JUMP
-};
-
-static void fill_layout_info(void)
-{
-    g_layout.oc_code_start = (uint32_t)oc_codestart;
-    g_layout.oc_code_size = oc_codesize;
-    g_layout.oc_stack_start = (uint32_t)oc_stackstart;
-    g_layout.oc_stack_size = oc_stacksize;
-    g_layout.oc_buffer_start = (uint32_t)oc_bufferstart;
-    g_layout.oc_buffer_size = oc_buffersize;
-}
-
-static void handle_get_info(struct usb_ctrlrequest *req)
-{
-    void *ptr = NULL;
-    int size = 0;
-    switch(req->wIndex)
-    {
-        case HWSTUB_INFO_VERSION:
-            ptr = &g_version;
-            size = sizeof(g_version);
-            break;
-        case HWSTUB_INFO_LAYOUT:
-            fill_layout_info();
-            ptr = &g_layout;
-            size = sizeof(g_layout);
-            break;
-        case HWSTUB_INFO_FEATURES:
-            ptr = &g_features;
-            size = sizeof(g_features);
-            break;
-        default:
-            size = target_get_info(req->wIndex, &ptr);
-            if(size < 0)
-                usb_drv_stall(EP_CONTROL, true, true);
-    }
-
-    if(ptr)
-    {
-        int length = MIN(size, req->wLength);
-        
-        if(ptr != usb_buffer)
-            memcpy(usb_buffer, ptr, length);
-        usb_drv_send(EP_CONTROL, usb_buffer, length);
-        usb_drv_recv(EP_CONTROL, NULL, 0);
-    }
-}
-
 static void handle_get_log(struct usb_ctrlrequest *req)
 {
     enable_logf(false);
@@ -421,28 +332,10 @@ static void handle_call_jump(struct usb_ctrlrequest *req)
     }
 }
 
-static void handle_atexit(struct usb_ctrlrequest *req)
-{
-    if(target_atexit(req->wIndex) < 0)
-        usb_drv_stall(EP_CONTROL, true, true);
-    else
-        usb_drv_send(EP_CONTROL, NULL, 0);
-}
-
-static void handle_exit(struct usb_ctrlrequest *req)
-{
-    (void)req;
-    usb_drv_send(EP_CONTROL, NULL, 0);
-    g_exit = true;
-}
-
 static void handle_class_dev_req(struct usb_ctrlrequest *req)
 {
     switch(req->bRequest)
     {
-        case HWSTUB_GET_INFO:
-            handle_get_info(req);
-            break;
         case HWSTUB_GET_LOG:
             handle_get_log(req);
             break;
@@ -453,11 +346,6 @@ static void handle_class_dev_req(struct usb_ctrlrequest *req)
         case HWSTUB_JUMP:
             handle_call_jump(req);
             break;
-        case HWSTUB_ATEXIT:
-            handle_atexit(req);
-            break;
-        case HWSTUB_EXIT:
-            handle_exit(req);
             break;
         default:
             usb_drv_stall(EP_CONTROL, true, true);
@@ -510,5 +398,4 @@ void main(uint32_t arg)
         }
     }
     usb_drv_exit();
-    target_exit();
 }
diff --git a/utils/hwstub/stub/rk27xx/target.c b/utils/hwstub/stub/rk27xx/target.c
index f9efccaef0..ff2e952909 100644
--- a/utils/hwstub/stub/rk27xx/target.c
+++ b/utils/hwstub/stub/rk27xx/target.c
@@ -33,7 +33,6 @@ enum rk27xx_family_t
 };
 
 static enum rk27xx_family_t g_rk27xx_family = UNKNOWN;
-static int g_atexit = HWSTUB_ATEXIT_OFF;
 
 static void _enable_irq(void)
 {
@@ -43,23 +42,6 @@ static void _enable_irq(void)
                  );
 }
 
-static void power_off(void)
-{
-    GPIO_PCCON &= ~(1<<0);
-    while(1);
-}
-
-static void rk27xx_reset(void)
-{
-    /* use Watchdog to reset */
-    SCU_CLKCFG &= ~CLKCFG_WDT;
-    WDTLR = 1;
-    WDTCON = (1<<4) | (1<<3);
-
-    /* Wait for reboot to kick in */
-    while(1);
-}
-
 /* us may be at most 2^31/200 (~10 seconds) for 200MHz max cpu freq */
 void target_udelay(int us)
 {
@@ -132,41 +114,22 @@ void target_init(void)
     }
 }
 
-static struct usb_resp_info_target_t g_target =
+struct hwstub_target_desc_t __attribute__((aligned(2))) target_descriptor =
 {
-    .id = HWSTUB_TARGET_RK27,
-    .name = "Rockchip RK27XX"
+    sizeof(struct hwstub_target_desc_t),
+    HWSTUB_DT_TARGET,
+    HWSTUB_TARGET_RK27,
+    "Rockchip RK27XX"
 };
 
-int target_get_info(int info, void **buffer)
+void target_get_desc(int desc, void **buffer)
 {
-    if(info == HWSTUB_INFO_TARGET)
-    {
-        *buffer = &g_target;
-        return sizeof(g_target);
-    }
-    else
-        return -1;
+    (void) desc;
+    *buffer = NULL;
 }
 
-int target_atexit(int method)
+void target_get_config_desc(void *buffer, int *size)
 {
-    g_atexit = method;
-    return 0;
-}
-
-void target_exit(void)
-{
-    switch(g_atexit)
-    {
-        case HWSTUB_ATEXIT_OFF:
-            power_off();
-            // fallthrough in case of return
-        case HWSTUB_ATEXIT_REBOOT:
-            rk27xx_reset();
-            // fallthrough in case of return
-        case HWSTUB_ATEXIT_NOP:
-        default:
-            return;
-    }
+    (void) buffer;
+    (void) size;
 }
diff --git a/utils/hwstub/stub/stmp/target.c b/utils/hwstub/stub/stmp/target.c
index 98f65da625..8d48707088 100644
--- a/utils/hwstub/stub/stmp/target.c
+++ b/utils/hwstub/stub/stmp/target.c
@@ -22,6 +22,7 @@
 #include "target.h"
 #include "system.h"
 #include "logf.h"
+#include "memory.h"
 
 #define __REG_SET(reg)  (*((volatile uint32_t *)(&reg + 1)))
 #define __REG_CLR(reg)  (*((volatile uint32_t *)(&reg + 2)))
@@ -50,34 +51,6 @@ enum stmp_family_t
 };
 
 static enum stmp_family_t g_stmp_family = UNKNOWN;
-static int g_atexit = HWSTUB_ATEXIT_OFF;
-
-/**
- *
- * Power
- *
- */
-
-#define HW_POWER_BASE       0x80044000
-
-void power_off(void)
-{
-    switch(g_stmp_family)
-    {
-        case STMP3600:
-            *(volatile uint32_t *)(HW_POWER_BASE + 0xc0) = 0x3e770014;
-            break;
-        case STMP3700:
-        case STMP3770:
-            *(volatile uint32_t *)(HW_POWER_BASE + 0xe0) = 0x3e770001;
-            break;
-        case STMP3780:
-            *(volatile uint32_t *)(HW_POWER_BASE + 0x100) = 0x3e770001;
-            break;
-        default:
-            break;
-    }
-}
 
 /**
  *
@@ -114,25 +87,6 @@ void power_off(void)
 #define HW_CLKCTRL_UTMICLKCTRL__UTMI_CLK30M_GATE    (1 << 30)
 #define HW_CLKCTRL_UTMICLKCTRL__UTMI_CLK120M_GATE   (1 << 31)
 
-void clkctrl_reset(void)
-{
-    switch(g_stmp_family)
-    {
-        case STMP3600:
-            *(volatile uint32_t *)(HW_POWER_BASE + 0xc0) = 0x3e770002;
-            break;
-        case STMP3700:
-        case STMP3770:
-            *(volatile uint32_t *)(HW_CLKCTRL_BASE + 0xf0) = 0x1;
-            break;
-        case STMP3780:
-            *(volatile uint32_t *)(HW_CLKCTRL_BASE + 0x120) = 0x1;
-            break;
-        default:
-            break;
-    }
-}
-
 /**
  *
  * Digctl
@@ -143,11 +97,18 @@ void clkctrl_reset(void)
 #define HW_DIGCTL_BASE          0x8001C000
 #define HW_DIGCTL_CTRL          (*(volatile uint32_t *)(HW_DIGCTL_BASE + 0))
 #define HW_DIGCTL_CTRL__USB_CLKGATE (1 << 2)
+#define HW_DIGCTL_CTRL__PACKAGE_SENSE_ENABLE_STMP3600 (1 << 0)
+
+#define HW_DIGCTL_STATUS          (*(volatile uint32_t *)(HW_DIGCTL_BASE + 0x10))
+#define HW_DIGCTL_STATUS__PACKAGE_TYPE_BP   1
+#define HW_DIGCTL_STATUS__PACKAGE_TYPE_BM   (7 << 1)
+#define HW_DIGCTL_STATUS__PACKAGE_TYPE_STMP3600_BP  1
+#define HW_DIGCTL_STATUS__PACKAGE_TYPE_STMP3600_BM  (1 << 1)
 
 /* STMP3700+ */
 #define HW_DIGCTL_MICROSECONDS  (*(volatile uint32_t *)(HW_DIGCTL_BASE + 0xC0))
 /* STMP3600 */
-#define HW_DIGCTL_MICROSECONDS2 (*(volatile uint32_t *)(HW_DIGCTL_BASE + 0xB0))
+#define HW_DIGCTL_MICROSECONDS_STMP3600 (*(volatile uint32_t *)(HW_DIGCTL_BASE + 0xB0))
 
 #define HW_DIGCTL_CHIPID        (*(volatile uint32_t *)(HW_DIGCTL_BASE + 0x310))
 #define HW_DIGCTL_CHIPID__PRODUCT_CODE_BP   16
@@ -177,8 +138,25 @@ void clkctrl_reset(void)
 #define HW_RTC_CTRL             (*(volatile uint32_t *)(HW_RTC_BASE + 0))
 #define HW_RTC_CTRL__WATCHDOGEN (1 << 4)
 
+struct hwstub_target_desc_t __attribute__((aligned(2))) target_descriptor =
+{
+    sizeof(struct hwstub_target_desc_t),
+    HWSTUB_DT_TARGET,
+    HWSTUB_TARGET_STMP,
+    "STMP3600 / STMP3700 / STMP3780 (i.MX233)"
+};
+
+static struct hwstub_stmp_desc_t __attribute__((aligned(2))) stmp_descriptor =
+{
+    sizeof(struct hwstub_stmp_desc_t),
+    HWSTUB_DT_STMP,
+    0, 0, 0
+};
+
 void target_init(void)
 {
+    stmp_descriptor.wChipID = __XTRACT(HW_DIGCTL_CHIPID, PRODUCT_CODE);
+    stmp_descriptor.bRevision = __XTRACT(HW_DIGCTL_CHIPID, REVISION);
     /* detect family */
     uint16_t product_code = __XTRACT(HW_DIGCTL_CHIPID, PRODUCT_CODE);
     if(product_code >= 0x3600 && product_code < 0x3700)
@@ -208,6 +186,7 @@ void target_init(void)
 
     if(g_stmp_family == STMP3600)
     {
+        stmp_descriptor.bPackage = __XTRACT(HW_DIGCTL_STATUS, PACKAGE_TYPE);
         /* CPU clock is always derived from PLL, if we switch to PLL, cpu will
          * run at 480 MHz unprepared ! That's bad so prepare to run at slow sleed
          * (1.2MHz) for a safe transition */
@@ -230,7 +209,13 @@ void target_init(void)
         __REG_CLR(HW_CLKCTRL_UTMICLKCTRL) = HW_CLKCTRL_UTMICLKCTRL__UTMI_CLK30M_GATE;
     }
     else
+    {
+        __REG_SET(HW_DIGCTL_CTRL) = HW_DIGCTL_CTRL__PACKAGE_SENSE_ENABLE_STMP3600;
+        stmp_descriptor.bPackage = __XTRACT(HW_DIGCTL_STATUS, PACKAGE_TYPE_STMP3600);
+        __REG_CLR(HW_DIGCTL_CTRL) = HW_DIGCTL_CTRL__PACKAGE_SENSE_ENABLE_STMP3600;
+
         __REG_SET(HW_CLKCTRL_PLLCTRL0) = HW_CLKCTRL_PLLCTRL0__POWER;
+    }
     /* enable USB PHY PLL */
     __REG_SET(HW_CLKCTRL_PLLCTRL0) = HW_CLKCTRL_PLLCTRL0__EN_USB_CLKS;
     /* power up USB PHY */
@@ -240,57 +225,24 @@ void target_init(void)
     __REG_CLR(HW_DIGCTL_CTRL) = HW_DIGCTL_CTRL__USB_CLKGATE;
 }
 
-static struct usb_resp_info_stmp_t g_stmp;
-static struct usb_resp_info_target_t g_target =
-{
-    .id = HWSTUB_TARGET_STMP,
-    .name = "STMP3600 / STMP3700 / STMP3780 (i.MX233)"
-};
-
-int target_get_info(int info, void **buffer)
+void target_get_desc(int desc, void **buffer)
 {
-    if(info == HWSTUB_INFO_STMP)
-    {
-        g_stmp.chipid = __XTRACT(HW_DIGCTL_CHIPID, PRODUCT_CODE);
-        g_stmp.rev = __XTRACT(HW_DIGCTL_CHIPID, REVISION);
-        g_stmp.is_supported = g_stmp_family != 0;
-        *buffer = &g_stmp;
-        return sizeof(g_stmp);
-    }
-    else if(info == HWSTUB_INFO_TARGET)
-    {
-        *buffer = &g_target;
-        return sizeof(g_target);
-    }
+    if(desc == HWSTUB_DT_STMP)
+        *buffer = &stmp_descriptor;
     else
-        return -1;
+        *buffer = NULL;
 }
 
-int target_atexit(int method)
+void target_get_config_desc(void *buffer, int *size)
 {
-    g_atexit = method;
-    return 0;
-}
-
-void target_exit(void)
-{
-    switch(g_atexit)
-    {
-        case HWSTUB_ATEXIT_OFF:
-            power_off();
-            // fallthrough in case of return
-        case HWSTUB_ATEXIT_REBOOT:
-            clkctrl_reset();
-            // fallthrough in case of return
-        case HWSTUB_ATEXIT_NOP:
-        default:
-            return;
-    }
+    memcpy(buffer, &stmp_descriptor, sizeof(stmp_descriptor));
+    *size += sizeof(stmp_descriptor);
 }
 
 void target_udelay(int us)
 {
-    volatile uint32_t *reg = g_stmp_family == STMP3600 ? &HW_DIGCTL_MICROSECONDS2 : &HW_DIGCTL_MICROSECONDS;
+    volatile uint32_t *reg = g_stmp_family == STMP3600 ? 
+        &HW_DIGCTL_MICROSECONDS_STMP3600 : &HW_DIGCTL_MICROSECONDS;
     uint32_t cur = *reg;
     uint32_t end = cur + us;
     if(cur < end)
diff --git a/utils/hwstub/stub/target.h b/utils/hwstub/stub/target.h
index 43151e9a34..cb17401a9c 100644
--- a/utils/hwstub/stub/target.h
+++ b/utils/hwstub/stub/target.h
@@ -25,15 +25,16 @@
 
 /* do target specific init */
 void target_init(void);
-/* exit, performing the atexit action (default is target specific) */
-void target_exit(void);
-/* get information, return actual size or -1 if error */
-int target_get_info(int info, void **buffer);
-/* set atexit action or return -1 on error */
-int target_atexit(int action);
+/* get descriptor, set buffer to NULL on error */
+void target_get_desc(int desc, void **buffer);
+/* pack all descriptors for config desc */
+void target_get_config_desc(void *buffer, int *size);
 /* Wait a very short time (us<=1000) */
 void target_udelay(int us);
 /* Wait for a short time (ms <= 1000) */
 void target_mdelay(int ms);
 
+/* mandatory for all targets */
+extern struct hwstub_target_desc_t target_descriptor;
+
 #endif /* __TARGET_H__ */