Merge tag 'v1.9.2' into parse-bytecode

Double precision math library and support on pyboard, and improved ussl

This release brings general improvements and bug fixes to the core and
various ports, as well as documentation additions, clean-ups and better
consistency.  And effort has been made to clean up the source code to
make it more consistent across the core and all ports.

There is a new tool "mpy_bin2res.py" to convert arbitrary (binary) files
to Python resources for inclusion in source code (frozen or otherwise).

The ussl module has seen improvements, including implementation of
server_hostname (for axtls) and server_side mode (for mbedtls).

There is now a double-precision float math library and stmhal has support
to build firmware with software or hardware double-precision.

A detailed list of changes follows.

py core:
- formatfloat: fix number of digits and exponent sign when rounding
- modthread: raise RuntimeError in release() if lock is not acquired
- compile: raise SyntaxError if positional args are given after */**
- objint: support "big" byte-order in int.to_bytes()
- objint: in to_bytes(), allow length arg to be any int and check sign
- compile: fix bug with break/continue in else of optimised for-range
- compile: optimise emitter label indices to save a word of heap
- builtinimport: remove unreachable code for relative imports
- objnamedtuple: simplify and remove use of alloca building namedtuple
- mpprint: remove unreachable check for neg return of mp_format_float
- binary: add missing "break" statements
- runtime: mark m_malloc_fail() as NORETURN
- objstr: remove unnecessary "sign" variable in formatting code
- vm: make "if" control flow more obvious in YIELD_FROM opcode
- modmath: check for zero division in log with 2 args
- makeversionhdr.py: update to parse new release line in docs/conf.py
- objdict: factorise dict accessor helper to reduce code size
- change mp_uint_t to size_t in builtins code
- repl: change mp_uint_t to size_t in repl helpers
- compile: combine arith and bit-shift ops into 1 compile routine
- compile: use switch-case to match token and operator
- objgenerator: allow to hash generators and generator instances
- gc: refactor assertions in gc_free function
- vm: make n_state variable local to just set-up part of VM
- asmx64: support moving a 64-bit immediate to one of top 8 registers
- modmicropython: cast stack_limit value so it prints correctly
- builtinevex: add typechecking of globals/locals args to eval/exec
- py.mk: make berkeley-db C-defs apply only to relevant source files
- mperrno: allow mperrno.h to be correctly included before other hdrs
- mpz: make mpz_is_zero() an inline function
- implement raising a big-int to a negative power
- mkrules.mk: show frozen modules sizes together with executable size
- objtuple: allow to use inplace-multiplication operator on tuples
- objstr: raise an exception for wrong type on RHS of str binary op
- modsys: initial implementation of sys.getsizeof()
- binary.c: fix bug when packing big-endian 'Q' values
- add verbose debug compile-time flag MICROPY_DEBUG_VERBOSE
- binary: change internal bytearray typecode from 0 to 1
- objstringio: prevent offset wraparound for io.BytesIO objects
- objstringio: fix regression with handling SEEK_SET
- stream: seek: Consistently handle negative offset for SEEK_SET
- mkrules.mk: use "find -path" when searching for frozen obj files
- compile: remove unused pn_colon code when compiling func params
- objcomplex: remove unnecessary assignment of variable
- formatfloat: don't post-increment variable that won't be used again
- use "static inline" for funcs that should be inline
- asmthumb: use existing macro to properly clear the D-cache

extmod:
- modussl_axtls: update for axTLS 2.1.3
- modussl_axtls: implement server_hostname arg to wrap_socket()
- move modonewire.c from esp8266 to extmod directory
- modure: if input string is bytes, return bytes results too
- modubinascii: add check for empty buffer passed to hexlify
- modussl_axtls: allow to close ssl stream multiple times
- modussl_mbedtls: support server_side mode
- modussl_mbedtls: when reading and peer wants to close, return 0
- modframebuf: fix invalid stride for odd widths in GS4_HMSB fmt
- modussl_mbedtls: make socket.close() free all TLS resources
- modframebuf: consistently use "col" as name for colour variables
- modussl_mbedtls: implement non-blocking SSL sockets
- machine_signal: fix parsing of invert arg when Pin is first arg
- modframebuf: use correct initialization for .locals_dict
- modlwip: implement setsockopt(IP_ADD_MEMBERSHIP)
- modussl_mbedtls.c: add ussl.getpeercert() method
- modubinascii: rewrite mod_binascii_a2b_base64
- modubinascii: don't post-increment variable that won't be used
- modonewire: rename public module to mp_module_onewire
- for uos.stat interpret st_size member as an unsigned int
- use "static inline" for funcs that should be inline

lib:
- axtls: upgrade to axTLS 2.1.3 + MicroPython patchset
- libm/math: remove implementations of float conversion functions
- add libm_dbl, a double-precision math library, from musl-1.1.16

drivers:
- onewire: move onewire.py, ds18x20.py from esp8266 to drivers
- onewire: enable pull-up when init'ing the 1-wire pin

tools:
- gen-cpydiff: use case description as 3rd-level heading
- pyboard: add license header
- mpy_bin2res: tools to convert binary resources to Python module
- mpy-tool.py: don't generate const_table if it's empty
- mpy-tool.py: fix missing argument in dump() function

tests:
- net_inet/test_tls_sites.py: integration test for SSL connections
- net_inet: add tests for accept and connect in nonblocking mode
- basics: add tests for for-else statement
- net_inet: move tests which don't require full Internet to net_hosted
- connect_nonblock: refactor towards real net_hosted test
- auto detect floating point capabilites of the target
- import: add a test for the builtin __import__ function
- import: update comment now that uPy raises correct exception
- basics/namedtuple1: add test for creating with pos and kw args
- unix/extra_coverage: add test for mp_vprintf with bad fmt spec
- basics: add tests for arithmetic operators precedence
- cpydiff/modules_deque: elaborate workaround
- cpydiff/core_class_mro: move under Classes, add workaround
- cpydiff/core_arguments: move under Functions subsection
- cpydiff/core_class_supermultiple: same cause as core_class_mro
- cpydiff: improve wording, add more workarounds
- cpydiff: add case for str.ljust/rjust
- rename exec1.py to builtin_exec.py
- basics/builtin_exec: test various globals/locals args to exec()

minimal port:
- Makefile: enable gc-sections to remove unused code
- remove unused stmhal include from Makefile
- use size_t for mp_builtin_open argument

unix port:
- modtime: replace strftime() with localtime()
- mpconfigport.mk: update descriptions of readline and TLS options
- Makefile: disable assertions in the standard unix executable
- modjni: convert to mp_rom_map_elem_t
- for uos.stat interpret st_size member as an unsigned int

stmhal port:
- mpconfigport.h: remove config of PY_THREAD_GIL to use default
- make error messages more consistent across peripherals
- add initial implementation of Pin.irq() method
- add .value() method to Switch object, to mirror Pin and Signal
- move pybstdio.c to lib/utils/sys_stdio_mphal.c for common use
- add "quiet timing" enter/exit functions
- make available the _onewire module, for low-level bus control
- modules: provide sym-link to onewire.py driver
- boards/stm32f405.ld: increase FLASH_TEXT to end of 1MiB flash
- sdcard: allow a board to customise the SDIO pins
- add possibility to build with double-precision floating point
- boards: enable double-prec FP on F76x boards
- Makefile: use hardware double-prec FP for MCUs that support it
- Makefile: rename FLOAT_IMPL to MICROPY_FLOAT_IMPL to match C name
- Makefile: add CFLAGS_EXTRA to CFLAGS so cmdline can add options
- mpconfigport.h: allow MICROPY_PY_THREAD to be overridden
- boards: add configuration files for NUCLEO_F429ZI
- boards/NUCLEO_F429ZI: change USB config from HS to FS peripheral
- reduce size of ESPRUINO_PICO build so it fits in flash
- servo: make pyb.Servo(n) map to Pin('Xn') on all MCUs
- servo: don't compile servo code when it's not enabled
- use "static inline" for funcs that should be inline

cc3200 port:
- modusocket: simplify socket.makefile() function
- make non-zero socket timeout work with connect/accept/send
- modusocket: fix connect() when in non-blocking or timeout mode
- use the name MicroPython consistently in code

esp8266 port:
- Makefile: bump axTLS TLS record buffer size to 5K
- Makefile: allow FROZEN_DIR,FROZEN_MPY_DIR to be overridden
- Makefile: add LIB_SRC_C variable to qstr auto-extraction list
- make onewire module and support code usable by other ports
- modonewire: move low-level 1-wire bus code to modonewire.c
- modonewire: make timings static and remove onewire.timings func
- reinstate 1-wire scripts by sym-linking to drivers/onewire/
- move mp_hal_pin_open_drain from esp_mphal.c to machine_pin.c
- enable MICROPY_ENABLE_FINALISER
- README: make "Documentation" a top-level section
- machine_rtc: use correct arithmetic for aligning RTC mem len
- mpconfigport_512k: use terse error messages to get 512k to fit
- mpconfigport.h: make socket a weak link
- modesp: remove unused constants: STA_MODE, etc
- general: add known issue of WiFi RX buffers overflow
- use size_t for mp_builtin_open argument
- fix UART stop bit constants

zephyr port:
- Makefile: rework dependencies and "clean" target
- Makefile: revert prj.conf construction rule to the previous state
- remove long-obsolete machine_ptr_t typedef's
- Makefile: explicitly define default target as "all"
- modusocket: allow to use socketized net_context in upstream
- modusocket: socket, close: switch to native Zephyr socket calls
- modusocket: bind, connect, listen, accept: Swtich to native sockets
- modusocket: send: switch to native sockets
- modusocket: recv: switch to native sockets
- modusocket: fully switch to native Zephyr sockets
- modzephyr: add current_tid() and stacks_analyze() functions
- prj_base.conf: enable CONFIG_INIT_STACKS
- modusocket: update struct sockaddr family field name
- prj_96b_carbon.conf: re-enable networking on Carbon
- modzephyr: add shell_net_iface() function

docs:
- btree: add hints about opening db file and need to flush db
- select: rename to uselect, to match the actual module name
- license: update copyright year
- esp8266/tutorial/intro: discourage use of 512kb firmwares
- esp8266/tutorial/intro: Sphinx requires blank lines around literal blocks
- conf.py: include 3 levels of ToC in latexpdf output
- gc: mark mem_alloc()/mem_free() as uPy-specific
- gc: document gc.threshold() function
- builtins: list builtin exceptions
- conf.py: set default_role = 'any'
- lcd160cr: group related constants together and use full sentences
- ref/speed_python: update and make more hardware-neutral
- library/gc: fix grammar and improve readability of gc.threshold()
- move all ports docs to the single ToC
- topindex.html: remove link to wipy.io, it's no longer available
- conf.py: add .venv dir to exclude_patterns
- move topindex.html to templates/ subdir
- differences/index_template: use consistent heading casing
- builtins: add AssertionError, SyntaxError, ZeroDivisionError
- add glossary
- conf.py: switch to "new" format of intersphinx_mapping
- conf.py: add file for global replacements definition
- library: add CPython docs xref to each pertinent module
- replace.inc: add |see_cpython|, to xref individual symbols from CPython
- conf.py: set "version" and "release" to the same value
- *_index: drop "Indices and tables" pseudo-section
- pyboard: move hardware info into General Info chapter
- uerrno: document "uerrno" module
- esp8266/general.rst: fix name of NTP module
- pyboard: move info about using Windows from topindex to general
- uzlib: update description of decompress() and mention DecompIO
- pyboard/tutorial/amp_skin: add example for playing large WAV files
- library/ubinascii: update base64 docs
- library/usocket: move socket.error to its own section
- library/usocket: describe complete information on address formats
- glossary: elaborate on possible MicroPython port differences
- glossary: fix typos in micropython-lib paragraph
- index: rewrite introduction paragraph to avoid confusion
- use the name MicroPython consistently in documentation
- consistently link to micropython-lib in glossary

all:
- make more use of mp_raise_{msg,TypeError,ValueError} helpers
- unify header guard usage
- remove trailing spaces, per coding conventions
- don't include system errno.h when it's not needed
- use the name MicroPython consistently in comments
- make use of $(TOP) variable in Makefiles, instead of ".."
- raise exceptions via mp_raise_XXX
- make static dicts use mp_rom_map_elem_t type and MP_ROM_xxx macros

README:
- mention support for bytecode and frozen bytecode
- improve description of precompiled bytecode; mention mpy-cross

CODECONVENTIONS:
- clarify MicroPython changes sign-off process
- start to describe docs conventions
- describe docs use of markup for None/True/False

travis:
- build STM32F769DISC board instead of F7DISC to test dbl-prec FP
- pin cpp-coveralls at 0.3.12

1 files changed, 66 insertions, 247 deletions

diff --git a/zephyr/modusocket.c b/zephyr/modusocket.c
index cec0eec7c..e021c3a44 100644
--- a/zephyr/modusocket.c
+++ b/zephyr/modusocket.c
@@ -37,6 +37,9 @@
 #include <net/net_context.h>
 #include <net/net_pkt.h>
 #include <net/dns_resolve.h>
+#ifdef CONFIG_NET_SOCKETS
+#include <net/socket.h>
+#endif
 
 #define DEBUG_PRINT 0
 #if DEBUG_PRINT // print debugging info
@@ -47,11 +50,7 @@
 
 typedef struct _socket_obj_t {
     mp_obj_base_t base;
-    struct net_context *ctx;
-    union {
-        struct k_fifo recv_q;
-        struct k_fifo accept_q;
-    };
+    int ctx;
 
     #define STATE_NEW 0
     #define STATE_CONNECTING 1
@@ -62,42 +61,13 @@ typedef struct _socket_obj_t {
 
 STATIC const mp_obj_type_t socket_type;
 
-// k_fifo extended API
-
-static inline void *_k_fifo_peek_head(struct k_fifo *fifo)
-{
-#if KERNEL_VERSION_NUMBER < 0x010763 /* 1.7.99 */
-    return sys_slist_peek_head(&fifo->data_q);
-#else
-    return sys_slist_peek_head(&fifo->_queue.data_q);
-#endif
-}
-
-static inline void *_k_fifo_peek_tail(struct k_fifo *fifo)
-{
-#if KERNEL_VERSION_NUMBER < 0x010763 /* 1.7.99 */
-    return sys_slist_peek_tail(&fifo->data_q);
-#else
-    return sys_slist_peek_tail(&fifo->_queue.data_q);
-#endif
-}
-
-static inline void _k_fifo_wait_non_empty(struct k_fifo *fifo, int32_t timeout)
-{
-    struct k_poll_event events[] = {
-        K_POLL_EVENT_INITIALIZER(K_POLL_TYPE_FIFO_DATA_AVAILABLE, K_POLL_MODE_NOTIFY_ONLY, fifo),
-    };
-
-    k_poll(events, MP_ARRAY_SIZE(events), timeout);
-    DEBUG_printf("poll res: %d\n", events[0].state);
-}
-
 // Helper functions
 
 #define RAISE_ERRNO(x) { int _err = x; if (_err < 0) mp_raise_OSError(-_err); }
+#define RAISE_SOCK_ERRNO(x) { if ((int)(x) == -1) mp_raise_OSError(errno); }
 
 STATIC void socket_check_closed(socket_obj_t *socket) {
-    if (socket->ctx == NULL) {
+    if (socket->ctx == -1) {
         // already closed
         mp_raise_OSError(EBADF);
     }
@@ -109,7 +79,7 @@ STATIC void parse_inet_addr(socket_obj_t *socket, mp_obj_t addr_in, struct socka
 
     mp_obj_t *addr_items;
     mp_obj_get_array_fixed_n(addr_in, 2, &addr_items);
-    sockaddr_in->sin_family = net_context_get_family(socket->ctx);
+    sockaddr_in->sin_family = net_context_get_family((void*)socket->ctx);
     RAISE_ERRNO(net_addr_pton(sockaddr_in->sin_family, mp_obj_str_get_str(addr_items[0]), &sockaddr_in->sin_addr));
     sockaddr_in->sin_port = htons(mp_obj_get_int(addr_items[1]));
 }
@@ -118,8 +88,8 @@ STATIC mp_obj_t format_inet_addr(struct sockaddr *addr, mp_obj_t port) {
     // We employ the fact that port and address offsets are the same for IPv4 & IPv6
     struct sockaddr_in6 *sockaddr_in6 = (struct sockaddr_in6*)addr;
     char buf[40];
-    net_addr_ntop(addr->family, &sockaddr_in6->sin6_addr, buf, sizeof(buf));
-    mp_obj_tuple_t *tuple = mp_obj_new_tuple(addr->family == AF_INET ? 2 : 4, NULL);
+    net_addr_ntop(addr->sa_family, &sockaddr_in6->sin6_addr, buf, sizeof(buf));
+    mp_obj_tuple_t *tuple = mp_obj_new_tuple(addr->sa_family == AF_INET ? 2 : 4, NULL);
 
     tuple->items[0] = mp_obj_new_str(buf, strlen(buf), false);
     // We employ the fact that port offset is the same for IPv4 & IPv6
@@ -127,7 +97,7 @@ STATIC mp_obj_t format_inet_addr(struct sockaddr *addr, mp_obj_t port) {
     //tuple->items[1] = mp_obj_new_int(ntohs(((struct sockaddr_in*)addr)->sin_port));
     tuple->items[1] = port;
 
-    if (addr->family == AF_INET6) {
+    if (addr->sa_family == AF_INET6) {
         tuple->items[2] = MP_OBJ_NEW_SMALL_INT(0); // flow_info
         tuple->items[3] = MP_OBJ_NEW_SMALL_INT(sockaddr_in6->sin6_scope_id);
     }
@@ -135,78 +105,9 @@ STATIC mp_obj_t format_inet_addr(struct sockaddr *addr, mp_obj_t port) {
     return MP_OBJ_FROM_PTR(tuple);
 }
 
-// Copy data from Zephyr net_buf chain into linear buffer.
-// We don't use net_pkt_read(), because it's weird (e.g., we'd like to
-// free processed data fragment ASAP, while net_pkt_read() holds onto
-// the whole fragment chain to do its deeds, and that's minor comparing
-// to the fact that it copies data byte by byte).
-static char *net_pkt_gather(struct net_pkt *pkt, char *to, unsigned max_len) {
-    struct net_buf *tmp = pkt->frags;
-
-    while (tmp && max_len) {
-        unsigned len = tmp->len;
-        if (len > max_len) {
-            len = max_len;
-        }
-        memcpy(to, tmp->data, len);
-        to += len;
-        max_len -= len;
-        tmp = net_pkt_frag_del(pkt, NULL, tmp);
-    }
-
-    return to;
-}
-
-// Callback for incoming packets.
-static void sock_received_cb(struct net_context *context, struct net_pkt *pkt, int status, void *user_data) {
-    socket_obj_t *socket = (socket_obj_t*)user_data;
-    DEBUG_printf("recv cb: context: %p, status: %d, pkt: %p", context, status, pkt);
-    if (pkt) {
-        DEBUG_printf(" (appdatalen=%d), token: %p", pkt->appdatalen, net_pkt_token(pkt));
-    }
-    DEBUG_printf("\n");
-    #if DEBUG_PRINT > 1
-    net_pkt_print_frags(pkt);
-    #endif
-
-    // if net_buf == NULL, EOF
-    if (pkt == NULL) {
-        struct net_pkt *last_pkt = _k_fifo_peek_tail(&socket->recv_q);
-        if (last_pkt == NULL) {
-            socket->state = STATE_PEER_CLOSED;
-            k_fifo_cancel_wait(&socket->recv_q);
-            DEBUG_printf("Marked socket %p as peer-closed\n", socket);
-        } else {
-            // We abuse "buf_sent" flag to store EOF flag
-            net_pkt_set_sent(last_pkt, true);
-            DEBUG_printf("Set EOF flag on %p\n", last_pkt);
-        }
-        return;
-    }
-
-    // Make sure that "EOF flag" is not set
-    net_pkt_set_sent(pkt, false);
-
-    // We don't care about packet header, so get rid of it asap
-    unsigned header_len = net_pkt_appdata(pkt) - pkt->frags->data;
-    net_buf_pull(pkt->frags, header_len);
-
-    k_fifo_put(&socket->recv_q, pkt);
-}
-
-// Callback for incoming connections.
-static void sock_accepted_cb(struct net_context *new_ctx, struct sockaddr *addr, socklen_t addrlen, int status, void *user_data) {
-    socket_obj_t *socket = (socket_obj_t*)user_data;
-    DEBUG_printf("accept cb: context: %p, status: %d, new ctx: %p\n", socket->ctx, status, new_ctx);
-    DEBUG_printf("new_ctx ref_cnt: %d\n", new_ctx->refcount);
-
-    k_fifo_put(&socket->accept_q, new_ctx);
-}
-
 socket_obj_t *socket_new(void) {
     socket_obj_t *socket = m_new_obj_with_finaliser(socket_obj_t);
     socket->base.type = (mp_obj_t)&socket_type;
-    k_fifo_init(&socket->recv_q);
     socket->state = STATE_NEW;
     return socket;
 }
@@ -215,10 +116,10 @@ socket_obj_t *socket_new(void) {
 
 STATIC void socket_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
     socket_obj_t *self = self_in;
-    if (self->ctx == NULL) {
+    if (self->ctx == -1) {
         mp_printf(print, "<socket NULL>");
     } else {
-        struct net_context *ctx = self->ctx;
+        struct net_context *ctx = (void*)self->ctx;
         mp_printf(print, "<socket %p type=%d>", ctx, net_context_get_type(ctx));
     }
 }
@@ -249,7 +150,8 @@ STATIC mp_obj_t socket_make_new(const mp_obj_type_t *type, size_t n_args, size_t
         }
     }
 
-    RAISE_ERRNO(net_context_get(family, socktype, proto, &socket->ctx));
+    socket->ctx = zsock_socket(family, socktype, proto);
+    RAISE_SOCK_ERRNO(socket->ctx);
 
     return MP_OBJ_FROM_PTR(socket);
 }
@@ -261,14 +163,9 @@ STATIC mp_obj_t socket_bind(mp_obj_t self_in, mp_obj_t addr_in) {
     struct sockaddr sockaddr;
     parse_inet_addr(socket, addr_in, &sockaddr);
 
-    RAISE_ERRNO(net_context_bind(socket->ctx, &sockaddr, sizeof(sockaddr)));
-    // For DGRAM socket, we expect to receive packets after call to bind(),
-    // but for STREAM socket, next expected operation is listen(), which
-    // doesn't work if recv callback is set.
-    if (net_context_get_type(socket->ctx) == SOCK_DGRAM) {
-        DEBUG_printf("Setting recv cb after bind\n");
-        RAISE_ERRNO(net_context_recv(socket->ctx, sock_received_cb, K_NO_WAIT, socket));
-    }
+    int res = zsock_bind(socket->ctx, &sockaddr, sizeof(sockaddr));
+    RAISE_SOCK_ERRNO(res);
+
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_2(socket_bind_obj, socket_bind);
@@ -280,9 +177,9 @@ STATIC mp_obj_t socket_connect(mp_obj_t self_in, mp_obj_t addr_in) {
     struct sockaddr sockaddr;
     parse_inet_addr(socket, addr_in, &sockaddr);
 
-    RAISE_ERRNO(net_context_connect(socket->ctx, &sockaddr, sizeof(sockaddr), NULL, K_FOREVER, NULL));
-    DEBUG_printf("Setting recv cb after connect()\n");
-    RAISE_ERRNO(net_context_recv(socket->ctx, sock_received_cb, K_NO_WAIT, socket));
+    int res = zsock_connect(socket->ctx, &sockaddr, sizeof(sockaddr));
+    RAISE_SOCK_ERRNO(res);
+
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_2(socket_connect_obj, socket_connect);
@@ -292,8 +189,9 @@ STATIC mp_obj_t socket_listen(mp_obj_t self_in, mp_obj_t backlog_in) {
     socket_check_closed(socket);
 
     mp_int_t backlog = mp_obj_get_int(backlog_in);
-    RAISE_ERRNO(net_context_listen(socket->ctx, backlog));
-    RAISE_ERRNO(net_context_accept(socket->ctx, sock_accepted_cb, K_NO_WAIT, socket));
+    int res = zsock_listen(socket->ctx, backlog);
+    RAISE_SOCK_ERRNO(res);
+
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_2(socket_listen_obj, socket_listen);
@@ -302,14 +200,12 @@ STATIC mp_obj_t socket_accept(mp_obj_t self_in) {
     socket_obj_t *socket = self_in;
     socket_check_closed(socket);
 
-    struct net_context *ctx = k_fifo_get(&socket->accept_q, K_FOREVER);
-    // Was overwritten by fifo
-    ctx->refcount = 1;
+    struct sockaddr sockaddr;
+    socklen_t addrlen = sizeof(sockaddr);
+    int ctx = zsock_accept(socket->ctx, &sockaddr, &addrlen);
 
     socket_obj_t *socket2 = socket_new();
     socket2->ctx = ctx;
-    DEBUG_printf("Setting recv cb after accept()\n");
-    RAISE_ERRNO(net_context_recv(ctx, sock_received_cb, K_NO_WAIT, socket2));
 
     mp_obj_tuple_t *client = mp_obj_new_tuple(2, NULL);
     client->items[0] = MP_OBJ_FROM_PTR(socket2);
@@ -322,28 +218,15 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(socket_accept_obj, socket_accept);
 
 STATIC mp_uint_t sock_write(mp_obj_t self_in, const void *buf, mp_uint_t size, int *errcode) {
     socket_obj_t *socket = self_in;
-    if (socket->ctx == NULL) {
+    if (socket->ctx == -1) {
         // already closed
         *errcode = EBADF;
         return MP_STREAM_ERROR;
     }
 
-    struct net_pkt *send_pkt = net_pkt_get_tx(socket->ctx, K_FOREVER);
-
-    unsigned len = net_if_get_mtu(net_context_get_iface(socket->ctx));
-    // Arbitrary value to account for protocol headers
-    len -= 64;
-    if (len > size) {
-        len = size;
-    }
-
-    // TODO: Return value of 0 is a hard case (as we wait forever, should
-    // not happen).
-    len = net_pkt_append(send_pkt, len, buf, K_FOREVER);
-
-    int err = net_context_send(send_pkt, /*cb*/NULL, K_FOREVER, NULL, NULL);
-    if (err < 0) {
-        *errcode = -err;
+    ssize_t len = zsock_send(socket->ctx, buf, size, 0);
+    if (len == -1) {
+        *errcode = errno;
         return MP_STREAM_ERROR;
     }
 
@@ -364,81 +247,16 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_2(socket_send_obj, socket_send);
 
 STATIC mp_uint_t sock_read(mp_obj_t self_in, void *buf, mp_uint_t max_len, int *errcode) {
     socket_obj_t *socket = self_in;
-    if (socket->ctx == NULL) {
+    if (socket->ctx == -1) {
         // already closed
         *errcode = EBADF;
         return MP_STREAM_ERROR;
     }
 
-    enum net_sock_type sock_type = net_context_get_type(socket->ctx);
-    unsigned recv_len;
-
-    if (sock_type == SOCK_DGRAM) {
-
-        struct net_pkt *pkt = k_fifo_get(&socket->recv_q, K_FOREVER);
-
-        recv_len = net_pkt_appdatalen(pkt);
-        DEBUG_printf("recv: pkt=%p, appdatalen: %d\n", pkt, recv_len);
-
-        if (recv_len > max_len) {
-            recv_len = max_len;
-        }
-
-        net_pkt_gather(pkt, buf, recv_len);
-        net_pkt_unref(pkt);
-
-    } else if (sock_type == SOCK_STREAM) {
-
-        do {
-
-            if (socket->state == STATE_PEER_CLOSED) {
-                return 0;
-            }
-
-            _k_fifo_wait_non_empty(&socket->recv_q, K_FOREVER);
-            struct net_pkt *pkt = _k_fifo_peek_head(&socket->recv_q);
-            if (pkt == NULL) {
-                DEBUG_printf("TCP recv: NULL return from fifo\n");
-                continue;
-            }
-
-            DEBUG_printf("TCP recv: cur_pkt: %p\n", pkt);
-
-            struct net_buf *frag = pkt->frags;
-            if (frag == NULL) {
-                printf("net_pkt has empty fragments on start!\n");
-                assert(0);
-            }
-
-            unsigned frag_len = frag->len;
-            recv_len = frag_len;
-            if (recv_len > max_len) {
-                recv_len = max_len;
-            }
-            DEBUG_printf("%d data bytes in head frag, going to read %d\n", frag_len, recv_len);
-
-            memcpy(buf, frag->data, recv_len);
-
-            if (recv_len != frag_len) {
-                net_buf_pull(frag, recv_len);
-            } else {
-                frag = net_pkt_frag_del(pkt, NULL, frag);
-                if (frag == NULL) {
-                    DEBUG_printf("Finished processing pkt %p\n", pkt);
-                    // Drop head packet from queue
-                    k_fifo_get(&socket->recv_q, K_NO_WAIT);
-
-                    // If "sent" flag was set, it's last packet and we reached EOF
-                    if (net_pkt_sent(pkt)) {
-                        socket->state = STATE_PEER_CLOSED;
-                    }
-                    net_pkt_unref(pkt);
-                }
-            }
-        // Keep repeating while we're getting empty fragments
-        // Zephyr IP stack appears to have fed empty net_buf's with empty
-        // frags for various TCP control packets - in previous versions.
-        } while (recv_len == 0);
+    ssize_t recv_len = zsock_recv(socket->ctx, buf, max_len, 0);
+    if (recv_len == -1) {
+        *errcode = errno;
+        return MP_STREAM_ERROR;
     }
 
     return recv_len;
@@ -483,30 +301,31 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(socket_makefile_obj, 1, 3, socket_mak
 
 STATIC mp_obj_t socket_close(mp_obj_t self_in) {
     socket_obj_t *socket = self_in;
-    if (socket->ctx != NULL) {
-        RAISE_ERRNO(net_context_put(socket->ctx));
-        socket->ctx = NULL;
+    if (socket->ctx != -1) {
+        int res = zsock_close(socket->ctx);
+        RAISE_SOCK_ERRNO(res);
+        socket->ctx = -1;
     }
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(socket_close_obj, socket_close);
 
-STATIC const mp_map_elem_t socket_locals_dict_table[] = {
-    { MP_OBJ_NEW_QSTR(MP_QSTR___del__), (mp_obj_t)&socket_close_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_close), (mp_obj_t)&socket_close_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_bind), (mp_obj_t)&socket_bind_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_connect), (mp_obj_t)&socket_connect_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_listen), (mp_obj_t)&socket_listen_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_accept), (mp_obj_t)&socket_accept_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_send), (mp_obj_t)&socket_send_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_recv), (mp_obj_t)&socket_recv_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_setsockopt), (mp_obj_t)&socket_setsockopt_obj },
-
-    { MP_OBJ_NEW_QSTR(MP_QSTR_read), (mp_obj_t)&mp_stream_read_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_readinto), (mp_obj_t)&mp_stream_readinto_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_readline), (mp_obj_t)&mp_stream_unbuffered_readline_obj},
-    { MP_OBJ_NEW_QSTR(MP_QSTR_write), (mp_obj_t)&mp_stream_write_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_makefile), (mp_obj_t)&socket_makefile_obj },
+STATIC const mp_rom_map_elem_t socket_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR___del__), MP_ROM_PTR(&socket_close_obj) },
+    { MP_ROM_QSTR(MP_QSTR_close), MP_ROM_PTR(&socket_close_obj) },
+    { MP_ROM_QSTR(MP_QSTR_bind), MP_ROM_PTR(&socket_bind_obj) },
+    { MP_ROM_QSTR(MP_QSTR_connect), MP_ROM_PTR(&socket_connect_obj) },
+    { MP_ROM_QSTR(MP_QSTR_listen), MP_ROM_PTR(&socket_listen_obj) },
+    { MP_ROM_QSTR(MP_QSTR_accept), MP_ROM_PTR(&socket_accept_obj) },
+    { MP_ROM_QSTR(MP_QSTR_send), MP_ROM_PTR(&socket_send_obj) },
+    { MP_ROM_QSTR(MP_QSTR_recv), MP_ROM_PTR(&socket_recv_obj) },
+    { MP_ROM_QSTR(MP_QSTR_setsockopt), MP_ROM_PTR(&socket_setsockopt_obj) },
+
+    { MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&mp_stream_read_obj) },
+    { MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_stream_readinto_obj) },
+    { MP_ROM_QSTR(MP_QSTR_readline), MP_ROM_PTR(&mp_stream_unbuffered_readline_obj) },
+    { MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&mp_stream_write_obj) },
+    { MP_ROM_QSTR(MP_QSTR_makefile), MP_ROM_PTR(&socket_makefile_obj) },
 };
 STATIC MP_DEFINE_CONST_DICT(socket_locals_dict, socket_locals_dict_table);
 
@@ -610,22 +429,22 @@ STATIC mp_obj_t pkt_get_info(void) {
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_0(pkt_get_info_obj, pkt_get_info);
 
-STATIC const mp_map_elem_t mp_module_usocket_globals_table[] = {
-    { MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_usocket) },
+STATIC const mp_rom_map_elem_t mp_module_usocket_globals_table[] = {
+    { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_usocket) },
     // objects
-    { MP_OBJ_NEW_QSTR(MP_QSTR_socket), (mp_obj_t)&socket_type },
+    { MP_ROM_QSTR(MP_QSTR_socket), MP_ROM_PTR(&socket_type) },
     // class constants
-    { MP_OBJ_NEW_QSTR(MP_QSTR_AF_INET), MP_OBJ_NEW_SMALL_INT(AF_INET) },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_AF_INET6), MP_OBJ_NEW_SMALL_INT(AF_INET6) },
+    { MP_ROM_QSTR(MP_QSTR_AF_INET), MP_ROM_INT(AF_INET) },
+    { MP_ROM_QSTR(MP_QSTR_AF_INET6), MP_ROM_INT(AF_INET6) },
 
-    { MP_OBJ_NEW_QSTR(MP_QSTR_SOCK_STREAM), MP_OBJ_NEW_SMALL_INT(SOCK_STREAM) },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_SOCK_DGRAM), MP_OBJ_NEW_SMALL_INT(SOCK_DGRAM) },
+    { MP_ROM_QSTR(MP_QSTR_SOCK_STREAM), MP_ROM_INT(SOCK_STREAM) },
+    { MP_ROM_QSTR(MP_QSTR_SOCK_DGRAM), MP_ROM_INT(SOCK_DGRAM) },
 
-    { MP_OBJ_NEW_QSTR(MP_QSTR_SOL_SOCKET), MP_OBJ_NEW_SMALL_INT(1) },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_SO_REUSEADDR), MP_OBJ_NEW_SMALL_INT(2) },
+    { MP_ROM_QSTR(MP_QSTR_SOL_SOCKET), MP_ROM_INT(1) },
+    { MP_ROM_QSTR(MP_QSTR_SO_REUSEADDR), MP_ROM_INT(2) },
 
-    { MP_OBJ_NEW_QSTR(MP_QSTR_getaddrinfo), (mp_obj_t)&mod_getaddrinfo_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_pkt_get_info), (mp_obj_t)&pkt_get_info_obj },
+    { MP_ROM_QSTR(MP_QSTR_getaddrinfo), MP_ROM_PTR(&mod_getaddrinfo_obj) },
+    { MP_ROM_QSTR(MP_QSTR_pkt_get_info), MP_ROM_PTR(&pkt_get_info_obj) },
 };
 
 STATIC MP_DEFINE_CONST_DICT(mp_module_usocket_globals, mp_module_usocket_globals_table);