Merge remote-tracking branch 'upstream/master'

Conflicts:
	core/newlib_syscalls.c

.dir-locals.el

@@ -6,4 +6,20 @@
   (c-file-style . "bsd")
   (c-basic-offset . 4)
   )
+ (asm-mode
+  (indent-tabs-mode . nil)
+  ; this is basically a hack so asm-mode indents with spaces not tabs
+  ; taken from http://stackoverflow.com/questions/2668563/emacs-indentation-in-asm-mode
+  ; (moving to gas-mode may be a better choice)
+  (tab-stop-list (quote (4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96 100 104 108 112 116 120)))
+  (asm-comment-char . "#")
+  )
  )
+
+; IMPORTANT: If you want to write assembly and have indenting to not be infuriating,
+; you probably also want this in your .emacs file:
+;
+; (add-hook 'asm-mode-hook '(lambda () (setq indent-line-function 'indent-relative)))
+;
+; This is not safe to set as a local variable.
+

FreeRTOS/Source/portable/esp8266/port.c

@@ -198,6 +198,8 @@ portBASE_TYPE xPortStartScheduler( void )
     }
 
     /* Initialize system tick timer interrupt and schedule the first tick. */
+    _xt_isr_attach(INUM_TICK, sdk__xt_timer_int);
+    _xt_isr_unmask(BIT(INUM_TICK));
     sdk__xt_tick_timer_init();
 
     vTaskSwitchContext();
@@ -265,60 +267,3 @@ void IRAM vPortExitCritical( void )
 	portENABLE_INTERRUPTS();
 }
 
-/*-----------------------------------------------------------*/
-
-/* Main ISR handler for FreeRTOS side of the ESP libs?
-
-   As far as I can tell, the "real" Xtensa ISRs ("Exceptions") are
-   handled in libmain.a (xtensa_vectors.o) which then can call into here
-   passing an interrupt mask.
-*/
-
-_xt_isr isr[16];
-
-void IRAM _xt_isr_attach(uint8_t i, _xt_isr func)
-{
-    isr[i] = func;
-}
-
-uint16_t IRAM _xt_isr_handler(uint16_t i)
-{
-    uint8_t index;
-
-    /* I think this is implementing some kind of interrupt priority or
-       short-circuiting an expensive ffs for most common interrupts - ie
-       WDT And GPIO are common or high priority, then remaining flags.
-    */
-    if (i & (1 << INUM_WDT)) {
-	index = INUM_WDT;
-    }
-    else if (i & (1 << INUM_GPIO)) {
-	index = INUM_GPIO;
-    }else {
-	index = __builtin_ffs(i) - 1;
-
-	if (index == INUM_MAX) {
-	    /* I don't understand what happens here. INUM_MAX is not
-	       the highest interrupt number listed (and the isr array
-	       has 16 entries).
-
-	       Clearing that flag and then setting index to
-	       __builtin_ffs(i)-1 may result in index == 255 if no
-	       higher flags are set, unless this is guarded against
-	       somehow by the caller?
-
-	       I also don't understand why the code is written like
-	       this in esp_iot_rtos_sdk instead of just putting the i
-	       &= line near the top... Probably no good reason?
-	    */
-	    i &= ~(1 << INUM_MAX);
-	    index = __builtin_ffs(i) - 1;
-	}
-    }
-
-    _xt_clear_ints(1<<index);
-
-    isr[index]();
-
-    return i & ~(1 << index);
-}

FreeRTOS/Source/portable/esp8266/portmacro.h

@@ -73,8 +73,8 @@ extern "C" {
 #include "esp8266.h"
 #include "espressif/esp8266/ets_sys.h"
 #include <stdint.h>
-#include    "xtensa_rtos.h"
+#include "xtensa_rtos.h"
-#include "xtensa_interrupts.h"
+#include <esp/interrupts.h>
 
 /*-----------------------------------------------------------
  * Port specific definitions for ESP8266

README.md

@@ -134,7 +134,17 @@ The best way to write suitable code is to first add documentation somewhere like
 
 ## Coding Style
 
-For new contributions, please use BSD style and indent using 4 spaces. If you're an emacs user then there is a .dir-locals.el file in the root which configures cc-mode.
+For new contributions in C, please use BSD style and indent using 4 spaces.
+
+For assembly, please use the following:
+* Instructions indented using 8 spaces.
+* Inline comments use `#` as a comment delimiter.
+* Comments on their own line(s) use `/*`..`*/`.
+* First operand of each instruction should be vertically aligned where possible.
+* For xtensa special registers, prefer `wsr aX, SR` over `wsr.SR aX`
+
+If you're an emacs user then there is a .dir-locals.el file in the root which configures cc-mode and asm-mode (you will need to approve some variable values as safe). See also
+the additional comments in .dir-locals.el, if you're editing assembly code.
 
 Upstream code is left with the indentation and style of the upstream project.
 

core/app_main.c

@@ -16,8 +16,8 @@
 #include "common_macros.h"
 #include "xtensa_ops.h"
 #include "esp/rom.h"
+#include "esp/uart.h"
 #include "esp/iomux_regs.h"
-#include "esp/uart_regs.h"
 #include "esp/spi_regs.h"
 #include "esp/dport_regs.h"
 #include "esp/wdev_regs.h"
@@ -30,7 +30,6 @@
 
 void user_init(void);
 
-#define UART_DIVISOR 1068  // 74906 bps (yeah, I don't understand it either)
 #define BOOT_INFO_SIZE 28
 //TODO: phy_info should probably be a struct (no idea about its organization, though)
 #define PHY_INFO_SIZE 128
@@ -82,8 +81,6 @@ xTaskHandle sdk_xWatchDogTaskHandle;
 
 static void IRAM get_otp_mac_address(uint8_t *buf);
 static void IRAM set_spi0_divisor(uint32_t divisor);
-static int IRAM default_putc(char c);
-static void IRAM default_putc1(char c);
 static void zero_bss(void);
 static void init_networking(uint8_t *phy_info, uint8_t *mac_addr);
 static void init_g_ic(void);
@@ -160,27 +157,15 @@ void IRAM sdk_user_fatal_exception_handler(void) {
     Cache_Read_Disable();
     Cache_Read_Enable(0, 0, 1);
     dump_excinfo();
-    while (FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(0).STATUS)) {}
+    uart_flush_txfifo(0);
-    while (FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(1).STATUS)) {}
+    uart_flush_txfifo(1);
     sdk_system_restart_in_nmi();
     halt();
 }
 
-// .Lfunc003 -- .text+0x1d0
-static int IRAM default_putc(char c) {
-    while (FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(0).STATUS) > 125) {}
-    UART(0).FIFO = c;
-    return 0;
-}
 
-// .Lfunc004 -- .text+0x1f4
+static void IRAM default_putc(char c) {
-static void IRAM default_putc1(char c) {
+    uart_putc(0, c);
-    if (c == '\n') {
-        default_putc('\r');
-    } else if (c == '\r') {
-        return;
-    }
-    default_putc(c);
 }
 
 // .text+0x258
@@ -247,7 +232,7 @@ void IRAM sdk_user_start(void) {
     sdk_SPIRead(ic_flash_addr, buf32, sizeof(struct sdk_g_ic_saved_st));
     Cache_Read_Enable(0, 0, 1);
     zero_bss();
-    sdk_os_install_putc1(default_putc1);
+    sdk_os_install_putc1(default_putc);
     if (cksum_magic == 0xffffffff) {
         // No checksum required
     } else if ((cksum_magic == 0x55aa55aa) &&
@@ -293,8 +278,8 @@ static void init_networking(uint8_t *phy_info, uint8_t *mac_addr) {
         printf("FATAL: sdk_register_chipv6_phy failed");
         halt();
     }
-    sdk_uart_div_modify(0, UART_DIVISOR);
+    uart_set_baud(0, 74906);
-    sdk_uart_div_modify(1, UART_DIVISOR);
+    uart_set_baud(1, 74906);
     sdk_phy_disable_agc();
     sdk_ieee80211_phy_init(sdk_g_ic.s.phy_mode);
     sdk_lmacInit();
@@ -378,15 +363,6 @@ static void dump_excinfo(void) {
     sdk_system_rtc_mem_write(0, excinfo, 32);
 }
 
-// .irom0.text+0x368
-int sdk_uart_rx_one_char(char *buf) {
-    if (FIELD2VAL(UART_STATUS_RXFIFO_COUNT, UART(0).STATUS)) {
-        *buf = UART(0).FIFO;
-        return 0;
-    }
-    return 1;
-}
-
 // .irom0.text+0x398
 void sdk_wdt_init(void) {
     WDT.CTRL &= ~WDT_CTRL_ENABLE;
@@ -455,9 +431,11 @@ static void user_start_phase2(void) {
     phy_info = malloc(PHY_INFO_SIZE);
     sdk_spi_flash_read(sdk_flashchip.chip_size - sdk_flashchip.sector_size * 4, (uint32_t *)phy_info, PHY_INFO_SIZE);
 
+    // Disable default buffering on stdout
+    setbuf(stdout, NULL);
     // Wait for UARTs to finish sending anything in their queues.
-    while (FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(0).STATUS) > 0) {}
+    uart_flush_txfifo(0);
-    while (FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(1).STATUS) > 0) {}
+    uart_flush_txfifo(1);
 
     if (phy_info[0] != 5) {
         // Bad version byte.  Discard what we read and use default values

core/esp_interrupts.c

@@ -0,0 +1,39 @@
+/* ESP8266 Xtensa interrupt management functions
+ *
+ *
+ * Part of esp-open-rtos
+ * Copyright (C) 2015 Angus Gratton
+ * BSD Licensed as described in the file LICENSE
+ */
+#include <esp/interrupts.h>
+
+_xt_isr isr[16];
+
+void IRAM _xt_isr_attach(uint8_t i, _xt_isr func)
+{
+    isr[i] = func;
+}
+
+/* Generic ISR handler.
+
+   Handles all flags set for interrupts in 'intset'.
+*/
+uint16_t IRAM _xt_isr_handler(uint16_t intset)
+{
+    /* WDT has highest priority (occasional WDT resets otherwise) */
+    if(intset & BIT(INUM_WDT)) {
+        _xt_clear_ints(BIT(INUM_WDT));
+        isr[INUM_WDT]();
+        intset -= BIT(INUM_WDT);
+    }
+
+    while(intset) {
+        uint8_t index = __builtin_ffs(intset) - 1;
+        uint16_t mask = BIT(index);
+        _xt_clear_ints(mask);
+        isr[index]();
+        intset -= mask;
+    }
+
+    return 0;
+}

core/exception_vectors.S

@@ -25,12 +25,19 @@
 
         .section .bss
 
-NMIHandlerStack:                # stack space for NMI handler
+/* Stack space for NMI handler
-        .skip   4*0x100
-.LNMIHandlerStackTop:
-NMIRegisterSaved:               # register space for saving NMI registers
-        .skip   4*(16 + 6)
 
+   NMI handler stack high water mark measured at 0x134 bytes. Any use
+   of the NMI timer callback will add stack overhead as well.
+
+   The NMI handler does a basic check for stack overflow
+*/
+        .balign 16
+NMIHandlerStack:
+        .skip 0x200
+.NMIHandlerStackTop:
+
+        .balign 16
 LoadStoreErrorHandlerStack:
         .word   0       # a0
         .word   0       # (unused)
@@ -67,10 +74,7 @@ DebugExceptionVector:
         .org    VecBase + 0x20
 NMIExceptionVector:
         .type   NMIExceptionVector, @function
-
+        j   NMIExceptionHandler
-        wsr     a0, excsave3
-        call0   CallNMIExceptionHandler
-        rfi     3  # Should never be reached
 
         .org    VecBase + 0x30
 KernelExceptionVector:
@@ -371,96 +375,103 @@ call_user_start:
 
 /*************************** NMI Exception Handler ***************************/
 
+#define NMI_STACK_CANARY 0xABBABABA
+
         .section .vecbase.text, "x"
 
-/* Save register relative to a0 */
-.macro SAVE_REG register, regnum
-        s32i \register, a0, (4 * (\regnum + 6))
-.endm
-
-/* Load register relative to sp */
-.macro LOAD_REG register, regnum
-        l32i \register, sp, (4 * (\regnum + 6))
-.endm
-
         .literal_position
-
         .balign  16
-CallNMIExceptionHandler:
+NMIExceptionHandler:
-        .type   CallNMIExceptionHandler, @function
+        .type   NMIExceptionHandler, @function
 
-        movi    a0, NMIRegisterSaved
+        wsr     sp, excsave3	# excsave3 holds user stack
-        SAVE_REG a2, 2
+        movi    sp, .NMIHandlerStackTop - 0x40
-        SAVE_REG sp, 1
+        s32i    a0, sp, 0x00
-        SAVE_REG a3, 3
+        s32i    a2, sp, 0x04
-        rsr     a2, excsave3    # a2 is now former a0
+        s32i    a3, sp, 0x08
-        SAVE_REG a4, 4
+        s32i    a4, sp, 0x0c
-        SAVE_REG a2, 0
+        s32i    a5, sp, 0x10
-        rsr     a3, epc1
+        s32i    a6, sp, 0x14
-        rsr     a4, exccause
+        s32i    a7, sp, 0x18
-        SAVE_REG a3, -5
+        s32i    a8, sp, 0x1c
-        SAVE_REG a4, -4
+        s32i    a9, sp, 0x20
-        rsr     a3, excvaddr
+        s32i    a10, sp, 0x24
-        SAVE_REG a3, -3
+        s32i    a11, sp, 0x28
-        rsr     a3, excsave1
+        rsr     a0, epc1
-        SAVE_REG a3, -2
+        s32i    a0, sp, 0x2c
-        SAVE_REG a5, 5
+        rsr     a0, exccause
-        SAVE_REG a6, 6
+        s32i    a0, sp, 0x30
-        SAVE_REG a7, 7
+        rsr     a0, excsave1
-        SAVE_REG a8, 8
+        s32i    a0, sp, 0x34
-        SAVE_REG a9, 9
+        rsr     a0, excvaddr
-        SAVE_REG a10, 10
+        s32i    a0, sp, 0x38
-        SAVE_REG a11, 11
+        rsr     a0, sar
-        SAVE_REG a12, 12
+        s32i    a0, sp, 0x3c
-        SAVE_REG a13, 13
+        movi    a0, 0x23        # Override PS for NMI handler
-        SAVE_REG a14, 14
+        wsr     a0, ps
-        SAVE_REG a15, 15
-        movi    sp, .LNMIHandlerStackTop
-        movi    a0, 0
-        movi    a2, 0x23        # argument for handler
-        wsr     a2, ps
         rsync
-        rsr     a14, sar
+
-        s32i    a14, sp, 0      # this is also NMIRegisterSaved+0
+        /* mark the stack overflow point before we call the actual NMI handler */
+        movi    a0, NMIHandlerStack
+        movi    a2, NMI_STACK_CANARY
+        s32i    a2, a0, 0x00
+
         call0   sdk_wDev_ProcessFiq
-        l32i    a15, sp, 0
+
-        wsr     a15, sar
+        /* verify we didn't overflow */
-        movi    a2, 0x33
+        movi    a0, NMIHandlerStack
-        wsr     a2, ps
+        l32i    a3, a0, 0
+        movi    a2, NMI_STACK_CANARY
+        bne    a3, a2, .NMIFatalStackOverflow
+
+	l32i 	a0, sp, 0x3c
+	wsr	a0, sar
+	l32i	a0, sp, 0x38
+	wsr	a0, excvaddr
+	l32i	a0, sp, 0x34
+	wsr	a0, excsave1
+	l32i	a0, sp, 0x30
+	wsr	a0, exccause
+	l32i	a0, sp, 0x2c
+	wsr	a0, epc1
+	l32i	a11, sp, 0x28
+	l32i 	a10, sp, 0x24
+	l32i	a9, sp, 0x20
+	l32i	a8, sp, 0x1c
+	l32i	a7, sp, 0x18
+	l32i 	a6, sp, 0x14
+	l32i	a5, sp, 0x10
+	l32i	a4, sp, 0x0c
+	l32i	a3, sp, 0x08
+        movi    a0, 0x33    	  # Reset PS
+        wsr     a0, ps
         rsync
-        LOAD_REG a4, 4
+        /* set dport nmi status to 1 (wDev_ProcessFiq clears bit 0 and verifies it
-        LOAD_REG a5, 5
+         * stays cleared, see
-        LOAD_REG a6, 6
-        LOAD_REG a7, 7
-        LOAD_REG a8, 8
-        LOAD_REG a9, 9
-        LOAD_REG a10, 10
-        LOAD_REG a11, 11
-        LOAD_REG a12, 12
-        LOAD_REG a13, 13
-        LOAD_REG a14, 14
-        LOAD_REG a15, 15
-        LOAD_REG a2, -5
-        LOAD_REG a3, -4
-        wsr     a2, epc1
-        wsr     a3, exccause
-        LOAD_REG a2, -3
-        LOAD_REG a3, -2
-        wsr     a2, excvaddr
-        wsr     a3, excsave1
-        LOAD_REG a0, 0
-        /* set dport nmi status bit 0 (wDev_ProcessFiq clears & verifies this
-         * bit stays cleared, see
          * http://esp8266-re.foogod.com/wiki/WDev_ProcessFiq_%28IoT_RTOS_SDK_0.9.9%29)
          */
-        movi    a2, 0x3ff00000
+        movi    a0, 0x3ff00000
-        movi    a3, 0x1
+        movi    a2, 0x1
-        s32i    a3, a2, 0
+        s32i    a2, a0, 0
-        LOAD_REG a2, 2
+	l32i	a2, sp, 0x04
-        LOAD_REG a3, 3
+	l32i	a0, sp, 0x00
-        LOAD_REG a1, 1
+	movi	a1, 0x0
+	xsr	a1, excsave3       # Load stack back from excsave3, clear excsave3
         rfi     3
 
+        .section .rodata
+
+.NMIStackOverflowErrorMsg:
+        .string "\nFATAL: NMI Stack Overflow\n"
+
+        .section .vecbase.text, "x"
+
+.NMIFatalStackOverflow:
+        movi a2, .NMIStackOverflowErrorMsg
+        call0 printf
+.NMIInfiniteLoop:
+        j .NMIInfiniteLoop /* TODO: replace with call to abort() */
+
 /*********************** General UserException Handler ***********************/
 
         .section .vecbase.text, "x"
@@ -469,7 +480,6 @@ CallNMIExceptionHandler:
  * LoadStoreCause. */
 
         .literal_position
-
         .balign  4
 UserExceptionHandler:
         .type   UserExceptionHandler, @function
@@ -490,46 +500,28 @@ UserExceptionHandler:
         wsr     a0, ps
         rsync
         rsr     a2, exccause
-        beqi    a2, CAUSE_LVL1INT, UserHandleInterrupt
+        /* Any UserException cause other than a level 1 interrupt is fatal */
-        /* Any UserException cause other than level 1 interrupt should panic */
+        bnei    a2, CAUSE_LVL1INT, .LUserFailOtherExceptionCause
-UserFailOtherExceptionCause:
+.LUserHandleInterrupt:
-        break   1, 1
-        call0   sdk_user_fatal_exception_handler
-UserHandleInterrupt:
         rsil    a0, 1
         rsr     a2, intenable
         rsr     a3, interrupt
         movi    a4, 0x3fff
         and     a2, a2, a3
-        and     a2, a2, a4      # a2 = 0x3FFF & INTENABLE & INTERRUPT
+        and     a2, a2, a4       # a2 = 0x3FFF & INTENABLE & INTERRUPT
-UserHandleTimer:
-        movi    a3, 0xffbf
-        and     a3, a2, a3      # a3 = a2 with bit 6 cleared
-        bnez    a3, UserTimerDone   # If any non-timer interrupt bits set
-        movi    a3, 0x40
-        sub     a12, a2, a3     # a12 = a2 - 0x40 -- Will be zero if bit 6 set
-        call0   sdk__xt_timer_int  # tick timer interrupt
-        mov     a2, a12         # restore a2 from a12, ie zero
-        beqz    a2, UserIntDone
-UserTimerDone:
         call0   _xt_isr_handler
-        bnez    a2, UserHandleTimer
+        call0   sdk__xt_int_exit # once finished, jumps to _xt_user_exit via stack
-UserIntDone:
+
-        beqz    a2, UserIntExit
+        .literal_position
-        /* FIXME: this code will never be reached */
+.LUserFailOtherExceptionCause:
         break   1, 1
         call0   sdk_user_fatal_exception_handler
-UserIntExit:
-        call0   sdk__xt_int_exit  # jumps to _xt_user_exit. Never returns here
 
-        .section .text
+/* _xt_user_exit is pushed onto the stack as part of the user exception handler,
-
+   restores same set registers which were saved there and returns from exception */
-/* _xt_user_exit is used to exit interrupt context. */
-/* TODO: Find a better place for this to live. */
 _xt_user_exit:
         .global _xt_user_exit
         .type _xt_user_exit, @function
-
         l32i    a0, sp, 0x8
         wsr     a0, ps
         l32i    a0, sp, 0x4
@@ -538,4 +530,3 @@ _xt_user_exit:
         l32i    sp, sp, 0x10
         rsync
         rfe
-

core/include/esp/cpu.h

@@ -1,33 +0,0 @@
-/* esp/cpu.h
- *
- * Details relating to the ESP8266 Xtensa core.
- *
- */
-#ifndef _ESP_CPU_H
-#define _ESP_CPU_H
-#include <stdbool.h>
-
-/* Interrupt numbers for level 1 exception handler.
- *
- * Currently the UserExceptionVector calls down to _xt_isr_handler,
- * defined in port.c, for at least some of these interrupts. Some are handled
- * on the SDK side, though.
- */
-typedef enum {
-    INUM_SPI = 2,
-    INUM_GPIO = 4,
-    INUM_UART = 5,
-    INUM_MAX = 6, /* in some places this is documented as timer0 CCOMPARE0 interrupt */
-    INUM_SOFT = 7,
-    INUM_WDT = 8,
-    INUM_TIMER_FRC1 = 9,
-
-    /* FRC2 default handler. Configured by sdk_ets_timer_init, which
-       runs as part of default libmain.a startup code, assigns
-       interrupt handler to sdk_vApplicationTickHook+0x68
-     */
-    INUM_TIMER_FRC2 = 10,
-} xt_isr_num_t;
-
-#endif
-

core/include/esp/gpio.h

@@ -11,8 +11,7 @@
 #include <stdbool.h>
 #include "esp/gpio_regs.h"
 #include "esp/iomux.h"
-#include "esp/cpu.h"
+#include "esp/interrupts.h"
-#include "xtensa_interrupts.h"
 
 typedef enum {
     GPIO_INPUT,

core/include/esp/interrupts.h

@@ -1,4 +1,4 @@
-/* Xtensa interrupt management functions
+/* ESP8266 Xtensa interrupt management functions
  *
  * Some (w/ sdk_ prefix) are implemented in binary libs, rest are
  * inlines replacing functions in the binary libraries.
@@ -15,9 +15,27 @@
 #include <xtensa/hal.h>
 #include <common_macros.h>
 
+/* Interrupt numbers for level 1 exception handler. */
+typedef enum {
+    INUM_SPI = 2,
+    INUM_GPIO = 4,
+    INUM_UART = 5,
+    INUM_TICK = 6, /* RTOS timer tick, possibly xtensa CPU CCOMPARE0(?) */
+    INUM_SOFT = 7,
+    INUM_WDT = 8,
+    INUM_TIMER_FRC1 = 9,
+
+    /* FRC2 default handler. Configured by sdk_ets_timer_init, which
+       runs as part of default libmain.a startup code, assigns
+       interrupt handler to sdk_vApplicationTickHook+0x68
+     */
+    INUM_TIMER_FRC2 = 10,
+} xt_isr_num_t;
+
 void sdk__xt_int_exit (void);
 void _xt_user_exit (void);
 void sdk__xt_tick_timer_init (void);
+void sdk__xt_timer_int(void);
 void sdk__xt_timer_int1(void);
 
 INLINED uint32_t _xt_get_intlevel(void)

core/include/esp/timer.h

@@ -10,9 +10,8 @@
 #define _ESP_TIMER_H
 
 #include <stdbool.h>
-#include <xtensa_interrupts.h>
 #include "esp/timer_regs.h"
-#include "esp/cpu.h"
+#include "esp/interrupts.h"
 
 #ifdef	__cplusplus
 extern "C" {

core/include/esp/uart.h

@@ -0,0 +1,127 @@
+/** esp/uart.h
+ *
+ * Utility routines for working with UARTs
+ *
+ * Part of esp-open-rtos
+ * Copyright (C) 2015 Superhouse Automation Pty Ltd
+ * BSD Licensed as described in the file LICENSE
+ */
+#ifndef _ESP_UART_H
+#define _ESP_UART_H
+
+#include "esp/types.h"
+#include "esp/uart_regs.h"
+#include "esp/clocks.h"
+
+#define UART_FIFO_MAX 127
+
+/* Wait for at least `min_count` bytes of data to be available in the UART's
+ * receive FIFO
+ *
+ * Returns the number of bytes actually available for reading.
+ */
+static inline int uart_rxfifo_wait(int uart_num, int min_count) {
+    int count;
+    do {
+        count = FIELD2VAL(UART_STATUS_RXFIFO_COUNT, UART(uart_num).STATUS);
+    } while (count < min_count);
+    return count;
+}
+
+/* Wait for at least `min_count` bytes of space to be available in the UART's
+ * transmit FIFO
+ *
+ * Returns the number of bytes actually available in the write buffer.
+ */
+static inline int uart_txfifo_wait(int uart_num, int min_count) {
+    int count;
+    do {
+        count = UART_FIFO_MAX - FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(uart_num).STATUS);
+    } while (count < min_count);
+    return count;
+}
+
+/* Read a character from the UART.  Block until a character is available for
+ * reading.
+ *
+ * Returns the character read.
+ */
+static inline int uart_getc(int uart_num) {
+    uart_rxfifo_wait(uart_num, 1);
+    return UART(uart_num).FIFO;
+}
+
+/* Read a character from the UART.  Does not block.
+ *
+ * Returns the read character on success.  If the RX FIFO is currently empty
+ * (nothing to read), returns -1.
+ */
+static inline int uart_getc_nowait(int uart_num) {
+    if (FIELD2VAL(UART_STATUS_RXFIFO_COUNT, UART(uart_num).STATUS)) {
+        return UART(uart_num).FIFO;
+    }
+    return -1;
+}
+
+/* Write a character to the UART.  Blocks if necessary until there is space in
+ * the TX FIFO.
+ */
+static inline void uart_putc(int uart_num, char c) {
+    uart_txfifo_wait(uart_num, 1);
+    UART(uart_num).FIFO = c;
+}
+
+/* Write a character to the UART.  Does not block.
+ *
+ * Returns 0 on success.  If there is no space currently in the TX FIFO,
+ * returns -1.
+ */
+static inline int uart_putc_nowait(int uart_num, char c) {
+    if (FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(uart_num).STATUS) < UART_FIFO_MAX) {
+        UART(uart_num).FIFO = c;
+        return 0;
+    }
+    return -1;
+}
+
+/* Clear (discard) all pending write data in the TX FIFO */
+static inline void uart_clear_txfifo(int uart_num) {
+    uint32_t conf = UART(uart_num).CONF0;
+    UART(uart_num).CONF0 = conf | UART_CONF0_TXFIFO_RESET;
+    UART(uart_num).CONF0 = conf & ~UART_CONF0_TXFIFO_RESET;
+}
+
+/* Clear (discard) all pending read data in the RX FIFO */
+static inline void uart_clear_rxfifo(int uart_num) {
+    uint32_t conf = UART(uart_num).CONF0;
+    UART(uart_num).CONF0 = conf | UART_CONF0_RXFIFO_RESET;
+    UART(uart_num).CONF0 = conf & ~UART_CONF0_RXFIFO_RESET;
+}
+
+/* Wait until all pending output in the UART's TX FIFO has been sent out the
+ * serial port. */
+static inline void uart_flush_txfifo(int uart_num) {
+    while (FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(uart_num).STATUS) != 0) {}
+}
+
+/* Flush all pending input in the UART's RX FIFO
+ * (this is just another name for uart_clear_rxfifo)
+ */
+static inline void uart_flush_rxfifo(int uart_num) {
+    uart_clear_rxfifo(uart_num);
+}
+
+/* Set uart baud rate to the desired value */
+static inline void uart_set_baud(int uart_num, int bps)
+{
+    uint32_t divider = APB_CLK_FREQ / bps;
+    UART(uart_num).CLOCK_DIVIDER = divider;
+}
+
+/* Returns the current baud rate for the UART */
+static inline int uart_get_baud(int uart_num)
+{
+    return APB_CLK_FREQ / FIELD2VAL(UART_CLOCK_DIVIDER_VALUE, UART(uart_num).CLOCK_DIVIDER);
+}
+
+#endif /* _ESP_UART_H */

core/include/esp8266.h

@@ -13,7 +13,7 @@
 
 #include "common_macros.h"
 #include "esp/registers.h"
-#include "esp/cpu.h"
+#include "esp/interrupts.h"
 #include "esp/iomux.h"
 #include "esp/gpio.h"
 #include "esp/timer.h"

core/newlib_syscalls.c

@@ -9,6 +9,7 @@
 #include <sys/errno.h>
 #include <espressif/sdk_private.h>
 #include <common_macros.h>
+#include <esp/uart.h>
 #include <stdlib.h>
 
 IRAM caddr_t _sbrk_r (struct _reent *r, int incr)
@@ -32,38 +33,40 @@ IRAM caddr_t _sbrk_r (struct _reent *r, int incr)
     return (caddr_t) prev_heap_end;
 }
 
-/* syscall implementation for stdio write to UART
+/* syscall implementation for stdio write to UART */
-
-   at the moment UART functionality is all still in the binary SDK
- */
 long _write_r(struct _reent *r, int fd, const char *ptr, int len )
 {
     if(fd != r->_stdout->_file) {
         r->_errno = EBADF;
         return -1;
     }
-    for(int i = 0; i < len; i++)
+    for(int i = 0; i < len; i++) {
-	sdk_os_putc(ptr[i]);
+        /* Auto convert CR to CRLF, ignore other LFs (compatible with Espressif SDK behaviour) */
+        if(ptr[i] == '\r')
+            continue;
+        if(ptr[i] == '\n')
+            uart_putc(0, '\r');
+        uart_putc(0, ptr[i]);
+    }
     return len;
 }
 
-/* syscall implementation for stdio read from UART
+/* syscall implementation for stdio read from UART */
-
+long _read_r( struct _reent *r, int fd, char *ptr, int len )
-   at the moment UART functionality is all still in the binary SDK
-   but there is support for IRQ driven UART0 RX in extras/serial-driver
- */
-long __attribute__((weak)) _read_r( struct _reent *r, int fd, char *ptr, int len )
 {
+    int ch, i;
+
     if(fd != r->_stdin->_file) {
         r->_errno = EBADF;
         return -1;
     }
-    for(int i = 0; i < len; i++) {
+    uart_rxfifo_wait(0, 1);
-        char ch;
+    for(i = 0; i < len; i++) {
-        while (sdk_uart_rx_one_char(&ch)) ;
+        ch = uart_getc_nowait(0);
+        if (ch < 0) break;
         ptr[i] = ch;
     }
-    return len;
+    return i;
 }
 
 /* Stub syscall implementations follow, to allow compiling newlib functions that

core/sdk_compat.c

@@ -1,5 +1,5 @@
 /*
- * Wrappers for functions called by binary espressif libraries
+ * Compatibility routines for the Espressif SDK and its API
  *
  * Part of esp-open-rtos
  * Copyright (C) 2015 Superhouse Automation Pty Ltd
@@ -10,6 +10,8 @@
 #include <stdio.h>
 #include <common_macros.h>
 
+#include <esp/uart.h>
+
 void IRAM *zalloc(size_t nbytes)
 {
     return calloc(1, nbytes);
@@ -18,9 +20,8 @@ void IRAM *zalloc(size_t nbytes)
 extern void (*__init_array_start)(void);
 extern void (*__init_array_end)(void);
 
-/* Do things which should be done as part of the startup code, but aren't.
+/* Do things which should be done as part of the SDK startup code, but aren't.
-
+   TODO: Move into app_main.c
-   Can be replaced with _start() once we have open source startup code.
 */
 void sdk_compat_initialise()
 {
@@ -29,3 +30,15 @@ void sdk_compat_initialise()
     for ( p = &__init_array_start; p != &__init_array_end; ++p)
         (*p)();
 }
+
+/* UART RX function from Espressif SDK internals.
+ *
+ * Not part of published API.
+ */
+int sdk_uart_rx_one_char(char *buf) {
+    int c = uart_getc_nowait(0);
+    if(c < 0)
+        return 1;
+    *buf = (char)c;
+    return 0;
+}

examples/blink/blink.c

@@ -3,7 +3,7 @@
  * This sample code is in the public domain.
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "esp8266.h"
@@ -53,7 +53,7 @@ void blinkenRegisterTask(void *pvParameters)
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
     xTaskCreate(blinkenTask, (signed char *)"blinkenTask", 256, NULL, 2, NULL);
     //xTaskCreate(blinkenRegisterTask, (signed char *)"blinkenRegisterTask", 256, NULL, 2, NULL);
 }

examples/blink_timers/blink_timers.c

@@ -3,7 +3,7 @@
  * This sample code is in the public domain.
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "esp8266.h"
@@ -33,7 +33,7 @@ void frc2_interrupt_handler(void)
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
 
     /* configure GPIOs */
     gpio_enable(gpio_frc1, GPIO_OUTPUT);

examples/bmp180_i2c/bmp180_i2c.c

@@ -3,7 +3,7 @@
  * This sample code is in the public domain.
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 
 #include "FreeRTOS.h"
 #include "task.h"
@@ -87,7 +87,7 @@ void bmp180_task(void *pvParameters)
 void user_setup(void)
 {
     // Set UART Parameter
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
 
     // Give the UART some time to settle
     sdk_os_delay_us(500);

examples/button/button.c

@@ -6,7 +6,7 @@
  * This sample code is in the public domain.
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "queue.h"
@@ -75,7 +75,7 @@ void GPIO_HANDLER(void)
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
     gpio_enable(gpio, GPIO_INPUT);
 
     tsqueue = xQueueCreate(2, sizeof(uint32_t));

examples/cpp_01_tasks/cpp_tasks.cpp

@@ -31,6 +31,8 @@
 
 #include "espressif/esp_common.h"
 
+#include "esp/uart.h"
+
 /******************************************************************************************************************
  * task_1_t
  *
@@ -94,7 +96,7 @@ esp_open_rtos::thread::queue_t<uint32_t> MyQueue;
  */
 extern "C" void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
     
     MyQueue.queue_create(10);
     

examples/experiments/timers/timers.c

@@ -7,7 +7,7 @@
  * This experimental reverse engineering code is in the public domain.
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "esp8266.h"
@@ -118,7 +118,7 @@ void frc2_handler(void)
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
     xTaskCreate(timerRegTask, (signed char *)"timerRegTask", 1024, NULL, 2, NULL);
 
     TIMER(0).CTRL = VAL2FIELD(TIMER_CTRL_CLKDIV, TIMER_CLKDIV_256) | TIMER_CTRL_RELOAD;

examples/experiments/unaligned_load/unaligned_load.c

@@ -3,7 +3,7 @@
 #include "esp/rom.h"
 #include "esp/timer.h"
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "queue.h"
@@ -214,7 +214,7 @@ void sanity_tests(void);
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
 
     gpio_enable(2, GPIO_OUTPUT); /* used for LED debug */
     gpio_write(2, 1); /* active low */

examples/http_get/http_get.c

@@ -5,7 +5,7 @@
  * This sample code is in the public domain.,
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 
 #include <string.h>
 
@@ -114,7 +114,7 @@ void http_get_task(void *pvParameters)
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
     printf("SDK version:%s\n", sdk_system_get_sdk_version());
 
     struct sdk_station_config config = {

examples/http_get_mbedtls/http_get_mbedtls.c

@@ -10,7 +10,7 @@
  * Additions Copyright (C) 2015 Angus Gratton, Apache 2.0 License.
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 
 #include <string.h>
 
@@ -80,7 +80,6 @@ static void my_debug(void *ctx, int level,
         file = file_sep+1;
 
     printf("%s:%04d: %s", file, line, str);
-    fflush(stdout);
 }
 #endif
 
@@ -107,7 +106,6 @@ void http_get_task(void *pvParameters)
     mbedtls_x509_crt_init(&cacert);
     mbedtls_ctr_drbg_init(&ctr_drbg);
     printf("\n  . Seeding the random number generator...");
-    fflush(stdout);
 
     mbedtls_ssl_config_init(&conf);
 
@@ -126,7 +124,6 @@ void http_get_task(void *pvParameters)
      * 0. Initialize certificates
      */
     printf("  . Loading the CA root certificate ...");
-    fflush(stdout);
 
     ret = mbedtls_x509_crt_parse(&cacert, (uint8_t*)server_root_cert, strlen(server_root_cert)+1);
     if(ret < 0)
@@ -148,7 +145,6 @@ void http_get_task(void *pvParameters)
      * 2. Setup stuff
      */
     printf("  . Setting up the SSL/TLS structure...");
-    fflush(stdout);
 
     if((ret = mbedtls_ssl_config_defaults(&conf,
                                           MBEDTLS_SSL_IS_CLIENT,
@@ -182,7 +178,6 @@ void http_get_task(void *pvParameters)
        our network is probably working...
     */
     printf("Waiting for server DNS to resolve... ");
-    fflush(stdout);
     err_t dns_err;
     ip_addr_t host_ip;
     do {
@@ -198,7 +193,6 @@ void http_get_task(void *pvParameters)
          * 1. Start the connection
          */
         printf("  . Connecting to %s:%s...", WEB_SERVER, WEB_PORT);
-        fflush(stdout);
 
         if((ret = mbedtls_net_connect(&server_fd, WEB_SERVER,
                                       WEB_PORT, MBEDTLS_NET_PROTO_TCP)) != 0)
@@ -215,7 +209,6 @@ void http_get_task(void *pvParameters)
          * 4. Handshake
          */
         printf("  . Performing the SSL/TLS handshake...");
-        fflush(stdout);
 
         while((ret = mbedtls_ssl_handshake(&ssl)) != 0)
         {
@@ -251,7 +244,6 @@ void http_get_task(void *pvParameters)
          * 3. Write the GET request
          */
         printf("  > Write to server:");
-        fflush(stdout);
 
         int len = sprintf((char *) buf, GET_REQUEST);
 
@@ -271,7 +263,6 @@ void http_get_task(void *pvParameters)
          * 7. Read the HTTP response
          */
         printf("  < Read from server:");
-        fflush(stdout);
 
         do
         {
@@ -322,7 +313,6 @@ void http_get_task(void *pvParameters)
         printf("\n\nsuccesses = %d failures = %d\n", successes, failures);
         for(int countdown = successes ? 10 : 5; countdown >= 0; countdown--) {
             printf("%d... ", countdown);
-            fflush(stdout);
             vTaskDelay(1000 / portTICK_RATE_MS);
         }
         printf("\nStarting again!\n");
@@ -331,7 +321,7 @@ void http_get_task(void *pvParameters)
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
     printf("SDK version:%s\n", sdk_system_get_sdk_version());
 
     struct sdk_station_config config = {

examples/ota_basic/ota_basic.c

@@ -7,7 +7,7 @@
  * NOT SUITABLE TO PUT ON THE INTERNET OR INTO A PRODUCTION ENVIRONMENT!!!!
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "esp8266.h"
@@ -18,7 +18,7 @@
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
 
     rboot_config_t conf = rboot_get_config();
     printf("\r\n\r\nOTA Basic demo.\r\nCurrently running on flash slot %d / %d.\r\n\r\n",

examples/serial_echo/Makefile

@@ -0,0 +1,3 @@
+# Simple makefile for serial_echo example
+PROGRAM=serial_echo
+include ../../common.mk

examples/serial_echo/serial_echo.c

@@ -0,0 +1,42 @@
+/* Extremely simple example that just reads from stdin and echoes back on stdout
+ *
+ * Has an easter egg, which is if you type "QUACK" it'll quack 3 times back at you.
+ *
+ * This example code is in the public domain
+ */
+#include "espressif/esp_common.h"
+#include <esp/uart.h>
+#include <string.h>
+
+void user_init(void)
+{
+    uart_set_baud(0, 115200);
+    printf("SDK version:%s\n", sdk_system_get_sdk_version());
+    printf("Going into echo mode...\n");
+
+    /* By default stdout is line-buffered, so you only see output
+       after a newline is sent. This is helpful in a multithreaded
+       environment so output doesn't get chopped up within a line.
+
+       Here we want to see the echo immediately, so disable buffering.
+    */
+    setbuf(stdout, NULL);
+
+    while(1) {
+        int c = getchar();
+        if(c != EOF)
+            putchar(c);
+
+        /* Easter egg: check for a quack! */
+        static int quack;
+        if(c == "QUACK"[quack]) {
+            quack++;
+            if(quack == strlen("QUACK")) {
+                printf("\nQUACK\nQUACK\n");
+                quack = 0;
+            }
+        } else {
+            quack = 0;
+        }
+    }
+}

examples/simple/simple.c

@@ -1,7 +1,7 @@
 /* Very basic example that just demonstrates we can run at all!
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "queue.h"
@@ -36,7 +36,7 @@ static xQueueHandle mainqueue;
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
     printf("SDK version:%s\n", sdk_system_get_sdk_version());
     mainqueue = xQueueCreate(10, sizeof(uint32_t));
     xTaskCreate(task1, (signed char *)"tsk1", 256, &mainqueue, 2, NULL);

examples/simple_cplusplus/simple.cpp

@@ -3,11 +3,12 @@
    This sample code is in the public domain.
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "queue.h"
 
+#include <esp/uart.h>
+
 class Counter
 {
 private:
@@ -58,7 +59,7 @@ void task1(void *pvParameters)
 
 extern "C" void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
     printf("SDK version:%s\n", sdk_system_get_sdk_version());
     xTaskCreate(task1, (signed char *)"tsk1", 256, NULL, 2, NULL);
 }

examples/tests/hmac_test_vectors/hmac_test_vectors.c

@@ -8,7 +8,7 @@
  * This sample code is in the public domain.,
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "mbedtls/md.h"
 
@@ -130,7 +130,7 @@ static void test_md5(void)
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
 
     test_md5();
 

libc/xtensa-lx106-elf/include/newlib.h

@@ -31,7 +31,7 @@
 
 /* Optional reentrant struct support.  Used mostly on platforms with
    very restricted storage.  */
-/* #undef _WANT_REENT_SMALL */
+#define _WANT_REENT_SMALL 1
 
 /* Multibyte supported */
 /* #undef _MB_CAPABLE */

libc/xtensa-lx106-elf/include/sys/config.h

@@ -188,6 +188,8 @@
 #ifdef __XTENSA__
 #include <xtensa/config/core-isa.h>
 #define MALLOC_ALIGNMENT ((XCHAL_DATA_WIDTH) < 16 ? 16 : (XCHAL_DATA_WIDTH))
+/* esp8266-specific: shrink the default fd buffer size */
+#define __BUFSIZ__ 128
 #endif
 
 /* This block should be kept in sync with GCC's limits.h.  The point