Version 2.3.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>

ChangeLog

@@ -1,3 +1,104 @@
+2021-10-12  NIIBE Yutaka  <gniibe@fsij.org>
+
+	* VERSION: 2.3
+	* doc/chopstx.texi (VERSION): 2.3.
+
+2021-10-11  NIIBE Yutaka  <gniibe@fsij.org>
+
+	* mcu/usb-usbip.c (URB_DATA_SIZE): Tweak the value.
+
+2021-02-26  NIIBE Yutaka  <gniibe@fsij.org>
+
+	* VERSION: 2.2
+	* doc/chopstx.texi (VERSION): 2.2.
+
+2021-02-25  NIIBE Yutaka  <gniibe@fsij.org>
+
+	* rules.mk (MCFLAGS): Add -masm-syntax-unified.
+
+	* entry-cortex-m.c (entry): Use Thumb-16 instruction in unified
+	asm syntax.  This means that no output change for Cortex-M0,
+	but change for Cortex-M3/M4 (shorter, different semantics).
+
+	* example-fsm-55/reset.c (reset): Likewise.
+
+	* chopstx-cortex-m.c
+	[__ARM_ARCH_6M__] (involuntary_context_switch): Use unified syntax.
+	[__ARM_ARCH_7M__] (involuntary_context_switch): Use Thumb-16
+	instruction.
+	[__ARM_ARCH_6M__] (chx_handle_intr): Use unified syntax.
+	[__ARM_ARCH_7M__] (chx_handle_intr): Use Thumb-16 instruction.
+	[__ARM_ARCH_6M__] (voluntary_context_switch): Use unified syntax.
+	[__ARM_ARCH_7M__] (svc): Use Thumb-16 instruction.
+
+2021-02-19  NIIBE Yutaka  <gniibe@fsij.org>
+
+	* chopstx-cortex-m.c (chx_handle_intr): Fix SUB instruction.
+
+2021-02-17  NIIBE Yutaka  <gniibe@fsij.org>
+
+	* contrib/adc-gnu-linux.c (adc_start_conversion): Use getrandom.
+
+	* mcu/usb-usbip.c (usbip_run_server): Add start-up message.
+
+2021-02-16  NIIBE Yutaka  <gniibe@fsij.org>
+
+	* contrib/ackbtn-gnu-linux.c: New.
+
+2021-02-12  NIIBE Yutaka  <gniibe@fsij.org>
+
+	* VERSION: 2.1
+	* doc/chopstx.texi (VERSION): 2.1.
+
+2021-02-10  NIIBE Yutaka  <gniibe@fsij.org>
+
+	* example-cdc-gnu-linux/usb-cdc.c (tty_recv): Cancel the input.
+
+	* chopstx.c (chx_recv_irq): Bug fix when no waiter.
+
+	* chopstx-gnu-linux.c (chopstx_create_arch): Fix ARGC of
+	makecontext call.
+	(chx_idle): Support exit by SIGINT or SIGTERM.
+
+2021-02-09  NIIBE Yutaka  <gniibe@fsij.org>
+
+	* chopstx-gnu-linux.c (chopstx_create_arch): Clear TP.
+
+	* example-cdc-gnu-linux/sample.c (main): Handle timeout by canceling
+	input.
+
+	* chopstx-gnu-linux.c (voluntary_context_switch): Fix for the case
+	when chx_idle suggests no context switch (tp_prev == tp_next).
+
+2021-02-08  NIIBE Yutaka  <gniibe@fsij.org>
+
+	* entry-cortex-m.c (vector_table): No use of PENDV exception.
+	Use chx_handle_intr for SysTick.
+	* example-fsm-55/reset.c (vector): Likewise.
+
+	* chopstx-cortex-m.c (preempting): Remove.
+	(CPU_EXCEPTION_PRIORITY_PENDSV): Remove.
+	(chx_interrupt_controller_init): No setup for PENDV.
+	(chx_request_preemption_possibly): Remove.
+	(involuntary_context_switch): New.
+	(chx_timer_handler): Remove.
+	(chx_handle_intr): Use involuntary_context_switch directly.
+	(preempt): Remove.
+
+2021-02-05  NIIBE Yutaka  <gniibe@fsij.org>
+
+	* chopstx-cortex-m.c (preempting): New value to hold the pointer
+	to preempting thread, which will become RUNNING.
+	(chx_request_preemption_possibly): New.
+	(chx_timer_handler, chx_handle_intr): Use the new function.
+	(preempt): Recover R0 from PREEMPTING and clear PREEMPTING.
+	(svc): Don't share return path with preempt.
+
+2021-02-04  NIIBE Yutaka  <gniibe@fsij.org>
+
+	* board/board-fsm-55.h (VAL_GPIO_LED_MODER): Support SWD
+	debugging.
+
 2020-06-26  NIIBE Yutaka  <gniibe@fsij.org>
 
 	* VERSION: 2.0

NEWS

@@ -1,6 +1,58 @@
 NEWS - Noteworthy changes
 
 
+* Major changes in Chopstx 2.3
+
+  Released 2021-10-12
+
+** Fix of USB driver for GNU/Linux emulation
+
+Fix the value of URB_DATA_SIZE, so that Gnuk can work with PC/SC.
+
+
+* Major changes in Chopstx 2.2
+
+  Released 2021-02-25
+
+** Acknowledge button support for GNU/Linux emulation
+User is asked acknowledge by RET with standard input.
+
+** USB driver for GNU/Linux emulation
+It shows start-up message now.
+
+** ADC driver for GNU/Linux emulation
+It uses getrandom(2), output is not deterministic any more.
+
+** Bug fix for Cortex-M3/M4 Support
+In 2.1, preemption doesn't work well, because of the difference of
+assembler syntax.
+
+
+* Major changes in Chopstx 2.1
+
+  Released 2021-02-12
+
+** GNU/Linux emulation change
+The process can be asked to exit by SIGINT or SIGTERM.
+
+** Bug fix for interrupt handling
+The check to find waiting thread was wrong.  If no waiting thread,
+it failed.
+
+** Bug fix for GNU/Linux emulation
+In 2.0, GNU/Linux emulation doesn't work well with chx_idle when it
+handles interrupt synchronously and the waken thread is the same one
+which called chx_idle.
+
+** Bug fix for Cortex-M0/M3/M4 Support
+In 2.0, Cortex-M0 with no tail-chaining support (e.g. STM32F030)
+doesn't work.  In 2.0, Cortex-M3/M4 may fail when two or more
+interrupts occur simultaneously; A waken thread (which is about to
+preempt RUNNING) by the first interrupt may be lost (and never
+scheduled again), by the second interrupt handling before the call of
+preempt function.
+
+
 * Major changes in Chopstx 2.0
 
   Released 2020-06-26

README

@@ -1,6 +1,6 @@
 Chopstx - Threads and only Threads
-							 Version 2.0
-							  2020-06-26
+							 Version 2.3
+							  2021-10-12
 							Niibe Yutaka
 					     Flying Stone Technology
 
@@ -9,7 +9,7 @@ What's Chopstx?
 
 Chopstx is an RT thread library for STM32F103 and GD32F103 (ARM
 Cortex-M3), STM32F030 (ARM Cortex-M0), MKL27Z (ARM Cortex-M0plus),
-STM32L432 (ARM Cortex-M4), GD32V103 (RISC-V Bumblebee) and emulation
+STM32L432 (ARM Cortex-M4), GD32VF103 (RISC-V Bumblebee) and emulation
 on GNU/Linux.
 
 While most RTOSes come with many features, drivers, and protocol
@@ -28,7 +28,8 @@ Note that this library is _not_ related to the hand game:
     https://en.wikipedia.org/wiki/Chopsticks_(hand_game)
 
 Thanks to Yao Wei and Enrico Zini for giving me an opportunity
-visiting the wiki page above, when my children were playing the game.
+visiting the wiki page above in Debconf Taiwan, when my children were
+playing the game.
 
 
 License
@@ -65,7 +66,7 @@ Convenience function to determine the bottom of thread stack,
 configuration of thread size by compiler's output would be next things
 to be done.
 
-Experimental SMP port for Cortex-A7 is under development.  For SMP,
-more careful considerations for shared access to objects of struct
-chx_pq is needed.  So, modifications required will not be small.
+We have an experimental SMP port for Cortex-A7.  For SMP, more careful
+considerations for shared access to objects of struct chx_pq is
+needed.  So, modifications required will not be small.
 -- 

VERSION

@@ -1 +1 @@
-release/2.0
+release/2.3

board/board-fsm-55.h

@@ -19,10 +19,13 @@
 
 /*
  * Port A setup.
- * PA5  - ON (LED 1:ON 0:OFF)
  * PA4  - Pull DOWN
+ * PA5  - ON (LED 1:ON 0:OFF)
+ *
+ * PA13 - SWDIO
+ * PA14 - SWCLK
  */
-#define VAL_GPIO_LED_MODER   0x00145555 /* Output Pin0-7, Pin9 and Pin10 */
+#define VAL_GPIO_LED_MODER   0x28145555 /* Output Pin0-7, Pin9 and Pin10 */
 #define VAL_GPIO_LED_OTYPER  0x0000001f /* Open-drain for Pin0-4, Push-Pull*/
 #define VAL_GPIO_LED_OSPEEDR 0x003cffff /* High speed */
 #define VAL_GPIO_LED_PUPDR   0x00000000 /* No pull-up/pull-down */

chopstx-cortex-m.c

@@ -2,7 +2,7 @@
  * chopstx-cortex-m.c - Threads and only threads: Arch specific code
  *                      for Cortex-M0/M3/M4
  *
- * Copyright (C) 2013, 2014, 2015, 2016, 2017, 2018, 2019
+ * Copyright (C) 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2021
  *               Flying Stone Technology
  * Author: NIIBE Yutaka <gniibe@fsij.org>
  *
@@ -76,14 +76,14 @@ struct chx_stack_regs {
  * ---------------------
  * Prio 0x40: thread temporarily inhibiting schedule for critical region
  * ...
- * Prio 0xb0: systick, external interrupt, pendsv
+ * Prio 0xb0: systick, external interrupt
  * =====================================
  *
  * Cortex-M0
  * =====================================
  * Prio 0x00: thread temporarily inhibiting schedule for critical region
  * ...
- * Prio 0x40: systick, external interrupt, pendsv
+ * Prio 0x40: systick, external interrupt
  * Prio 0x80: svc (not used)
  * =====================================
  */
@@ -95,7 +95,6 @@ struct chx_stack_regs {
 /* ... */
 #define CPU_EXCEPTION_PRIORITY_SYSTICK       0x40
 #define CPU_EXCEPTION_PRIORITY_INTERRUPT     CPU_EXCEPTION_PRIORITY_SYSTICK
-#define CPU_EXCEPTION_PRIORITY_PENDSV        CPU_EXCEPTION_PRIORITY_SYSTICK
 #define CPU_EXCEPTION_PRIORITY_SVC           0x80 /* No use in this arch */
 #elif defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7EM__)
 #define CPU_EXCEPTION_PRIORITY_SVC           0x30
@@ -104,7 +103,6 @@ struct chx_stack_regs {
 /* ... */
 #define CPU_EXCEPTION_PRIORITY_SYSTICK       0xb0
 #define CPU_EXCEPTION_PRIORITY_INTERRUPT     CPU_EXCEPTION_PRIORITY_SYSTICK
-#define CPU_EXCEPTION_PRIORITY_PENDSV        CPU_EXCEPTION_PRIORITY_SYSTICK
 #else
 #error "no support for this arch"
 #endif
@@ -228,8 +226,7 @@ chx_interrupt_controller_init (void)
 {
   *AIRCR = 0x05FA0000 | ( 5 << 8); /* PRIGROUP = 5, 2-bit:2-bit. */
   *SHPR2 = (CPU_EXCEPTION_PRIORITY_SVC << 24);
-  *SHPR3 = ((CPU_EXCEPTION_PRIORITY_SYSTICK << 24)
-	    | (CPU_EXCEPTION_PRIORITY_PENDSV << 16));
+  *SHPR3 = (CPU_EXCEPTION_PRIORITY_SYSTICK << 24);
 }
 
 
@@ -256,37 +253,107 @@ chx_cpu_sched_unlock (void)
 }
 
 
-static void
-chx_request_preemption (void)
+static void __attribute__ ((naked, used))
+involuntary_context_switch (struct chx_thread *tp_next)
 {
-  *ICSR = (1 << 28);
-  asm volatile ("" : : : "memory");
+  register struct chx_thread *tp_current asm ("r1");
+
+  asm (
+	"ldr	r2, =running\n\t"
+	"ldr	r1, [r2]"
+	: "=r" (tp_current)
+	: /* no input */
+	: "r2");
+
+  if (!tp_current)
+    /* It's idle thread.  No need to save registers.  */
+    ;
+  else
+    {
+      /* Save registers onto CHX_THREAD struct.  */
+      asm volatile (
+	"adds	%0, #20\n\t"
+	"stm	%0!, {r4, r5, r6, r7}\n\t"
+	"mov	r2, r8\n\t"
+	"mov	r3, r9\n\t"
+	"mov	r4, r10\n\t"
+	"mov	r5, r11\n\t"
+	"mrs	r6, PSP\n\t" /* r13(=SP) in user space.  */
+	"stm	%0!, {r2, r3, r4, r5, r6}"
+	: "=r" (tp_current)
+	: "0" (tp_current)
+	  /*
+	   * Memory clobber constraint here is not accurate, but this
+	   * works.  R7 keeps its value, but having "r7" here prevents
+	   * use of R7 before this asm statement.
+	   */
+	: "cc", "r2", "r3", "r4", "r5", "r6", "r7", "memory");
+
+      tp_next = chx_running_preempted (tp_next);
+    }
+
+  /* Registers on stack (PSP): r0, r1, r2, r3, r12, lr, pc, xpsr */
+
+  asm volatile (
+	/* Now, r0 points to the thread to be switched.  */
+	/* Put it to *running.  */
+	"ldr	r1, =running\n\t"
+	/* Update running: chx_set_running */
+	"str	r0, [r1]\n\t"
+	/**/
+	"adds	r0, #20\n\t"
+	"ldm	r0!, {r4, r5, r6, r7}\n\t"
+#if defined(__ARM_ARCH_6M__)
+	"ldm	r0!, {r1, r2, r3}\n\t"
+	"mov	r8, r1\n\t"
+	"mov	r9, r2\n\t"
+	"mov	r10, r3\n\t"
+	"ldm	r0!, {r1, r2}\n\t"
+	"mov	r11, r1\n\t"
+	"msr	PSP, r2\n\t"
+#else
+	"ldr	r8, [r0], #4\n\t"
+	"ldr	r9, [r0], #4\n\t"
+	"ldr	r10, [r0], #4\n\t"
+	"ldr	r11, [r0], #4\n\t"
+	"ldr	r1, [r0], #4\n\t"
+	"msr	PSP, r1\n\t"
+#endif
+	"movs	r0, #0\n\t"
+	"subs	r0, #3\n\t" /* EXC_RETURN to a thread with PSP */
+	"bx	r0"
+	: /* no output */ : "r" (tp_next) : "memory");
 }
 
-struct chx_thread *
-chx_timer_handler (void)
-{
-  struct chx_thread *tp_next;
-  tp_next = chx_timer_expired ();
-  if (tp_next)
-    chx_request_preemption ();
-  return tp_next;
-}
+static struct chx_thread *chx_timer_expired (void) __attribute__ ((noinline,used));
+static struct chx_thread *chx_recv_irq (uint32_t irq_num) __attribute__ ((noinline,used));
 
-struct chx_thread *
+void __attribute__ ((naked))
 chx_handle_intr (void)
 {
-  register uint32_t irq_num;
-  struct chx_thread *tp_next;
+  register struct chx_thread *tp_next asm ("r0");;
 
   asm volatile ("mrs	%0, IPSR\n\t"
-		"sub	%0, #16"   /* Exception # - 16 = interrupt number.  */
-		: "=r" (irq_num) : /* no input */ : "memory");
+		/* Exception # - 16 = interrupt number.  */
+		"subs	%0, #16\n\t"
+		"bpl	0f\n\t"
+		"bl	chx_timer_expired\n\t"
+		"b	1f\n"
+	      "0:\n\t"
+		"bl	chx_recv_irq\n"
+	      "1:"
+		: "=r" (tp_next) : /* no input */ : "cc", "memory");
 
-  tp_next = chx_recv_irq (irq_num);
   if (tp_next)
-    chx_request_preemption ();
-  return tp_next;
+    asm volatile (
+	"b	involuntary_context_switch"
+	: /*no input */ : /* no input */ : "memory");
+  else
+    asm volatile (
+	"movs	r0, #0\n\t"
+	"subs	r0, #3\n\t" /* EXC_RETURN to a thread with PSP */
+	"bx	r0"
+	: /*no input */ : /* no input */ : "memory");
 }
 
 static void
@@ -305,14 +372,14 @@ voluntary_context_switch (struct chx_thread *tp_next)
 #if defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7EM__)
   asm volatile (
 	"svc	#0\n\t"
-        "add	r1, r0, #16\n\t"
-        "ldr	r0, [r1]"       /* Get tp->v */
-	: "=r" (result) : "0" (tp_next): "memory");
+	"add	r1, r0, #16\n\t"
+	"ldr	r0, [r1]"	/* Get tp->v */
+	: "=r" (result) : "0" (tp_next): "r1", "memory");
 #else
   register struct chx_thread *tp asm ("r1");
 
   /* Build stack data as if it were an exception entry.
-   * And set the stop top to has RUNNNING.
+   * And set the stack top to have RUNNNING.
    */
   /*
    * r0:  RUNNING               scratch
@@ -326,10 +393,10 @@ voluntary_context_switch (struct chx_thread *tp_next)
    */
   asm ("mov	%0, lr\n\t"
        "ldr	r2, =.L_CONTEXT_SWITCH_FINISH\n\t"
-       "mov	r3, #128\n\t"
-       "lsl	r3, #17\n\t"
+       "movs	r3, #128\n\t"
+       "lsls	r3, #17\n\t"
        "push	{%0, r2, r3}\n\t"
-       "mov	%0, #0\n\t"
+       "movs	%0, #0\n\t"
        "mov	r2, %0\n\t"
        "mov	r3, %0\n\t"
        "push	{%0, r2, r3}\n\t"
@@ -338,10 +405,10 @@ voluntary_context_switch (struct chx_thread *tp_next)
        "push	{%0, r3}\n\t"
        : "=r" (tp)
        : /* no input */
-       : "r2", "r3", "memory");
+       : "cc", "r2", "r3", "memory");
 
   /* Save registers onto CHX_THREAD struct.  */
-  asm ("add	r1, #20\n\t"
+  asm ("adds	r1, #20\n\t"
        "stm	r1!, {r4, r5, r6, r7}\n\t"
        "mov	r2, r8\n\t"
        "mov	r3, r9\n\t"
@@ -349,10 +416,10 @@ voluntary_context_switch (struct chx_thread *tp_next)
        "mov	r5, r11\n\t"
        "mov	r6, sp\n\t"
        "stm	r1!, {r2, r3, r4, r5, r6}\n\t"
-       "sub	r1, #56"
+       "subs	r1, #56"
        : /* no output */
        : "r" (tp)
-       : "r2", "r3", "r4", "r5", "r6", "r7", "memory");
+       : "cc", "r2", "r3", "r4", "r5", "r6", "r7", "memory");
 
   asm volatile (/* Now, r0 points to the thread to be switched.  */
 		/* Put it to *running.  */
@@ -373,7 +440,7 @@ voluntary_context_switch (struct chx_thread *tp_next)
 
 		/* Normal context switch */
 	"0:\n\t"
-		"add	r0, #20\n\t"
+		"adds	r0, #20\n\t"
 		"ldm	r0!, {r4, r5, r6, r7}\n\t"
 		"ldm	r0!, {r1, r2, r3}\n\t"
 		"mov	r8, r1\n\t"
@@ -398,12 +465,12 @@ voluntary_context_switch (struct chx_thread *tp_next)
 		  [28 or 32] <-- pc
 		*/
 		"ldr	r0, [sp, #28]\n\t"
-		"lsl	r1, r0, #23\n\t"
+		"lsls	r1, r0, #23\n\t"
 		"bcc	2f\n\t"
 		/**/
 		"ldr	r2, [sp, #24]\n\t"
-		"mov	r1, #1\n\t"
-		"orr	r2, r1\n\t"	/* Ensure Thumb-mode */
+		"movs	r1, #1\n\t"
+		"orrs	r2, r1\n\t"	/* Ensure Thumb-mode */
 		"str	r2, [sp, #32]\n\t"
 		"msr	APSR_nzcvq, r0\n\t"
 		/**/
@@ -416,8 +483,8 @@ voluntary_context_switch (struct chx_thread *tp_next)
 		"pop	{pc}\n"
 	"2:\n\t"
 		"ldr	r2, [sp, #24]\n\t"
-		"mov	r1, #1\n\t"
-		"orr	r2, r1\n\t"	/* Ensure Thumb-mode */
+		"movs	r1, #1\n\t"
+		"orrs	r2, r1\n\t"	/* Ensure Thumb-mode */
 		"str	r2, [sp, #28]\n\t"
 		"msr	APSR_nzcvq, r0\n\t"
 		/**/
@@ -429,13 +496,13 @@ voluntary_context_switch (struct chx_thread *tp_next)
 		"add	sp, #12\n\t"
 		"pop	{pc}\n\t"
 	".L_CONTEXT_SWITCH_FINISH:\n\t"
-		"add	r0, #16\n\t"
+		"adds	r0, #16\n\t"
 		"ldr	r0, [r0]"       /* Get tp->v */
 		: "=r" (result)		/* Return value in R0 */
 		: "0" (tp_next)
-		: "memory");
+		: "cc", "memory");
 #endif
-  return (uintptr_t)result;
+  return result;
 }
 
 extern void cause_link_time_error_unexpected_size_of_struct_chx_thread (void);
@@ -470,119 +537,6 @@ chopstx_create_arch (uintptr_t stack_addr, size_t stack_size,
   return tp;
 }
 
-/*
- * Lower layer architecture specific exception handling entries.
- *
- */
-
-void __attribute__ ((naked))
-preempt (struct chx_thread * tp_next)
-{
-  register struct chx_thread *tp_current asm ("r1");
-
-  asm (	"ldr	r2, =running\n\t"
-	"ldr	r1, [r2]"
-	: "=r" (tp_current)
-	: /* no input */
-	: "r2");
-
-  if (!tp_current)
-    /* It's idle thread.  No need to save registers.  */
-    ;
-  else
-    {
-      /* Save registers onto CHX_THREAD struct.  */
-      asm volatile (
-	"add	%0, #20\n\t"
-	"stm	%0!, {r4, r5, r6, r7}\n\t"
-	"mov	r2, r8\n\t"
-	"mov	r3, r9\n\t"
-	"mov	r4, r10\n\t"
-	"mov	r5, r11\n\t"
-	"mrs	r6, PSP\n\t" /* r13(=SP) in user space.  */
-	"stm	%0!, {r2, r3, r4, r5, r6}"
-	: "=r" (tp_current)
-	: "0" (tp_current)
-	  /*
-	   * Memory clobber constraint here is not accurate, but this
-	   * works.  R7 keeps its value, but having "r7" here prevents
-	   * use of R7 before this asm statement.
-	   */
-	: "r2", "r3", "r4", "r5", "r6", "r7", "memory");
-
-      tp_next = chx_running_preempted (tp_next);
-    }
-
-  /* Registers on stack (PSP): r0, r1, r2, r3, r12, lr, pc, xpsr */
-
-  asm volatile (
-    ".L_CONTEXT_SWITCH:\n\t"
-	/* Now, r0 points to the thread to be switched.  */
-	/* Put it to *running.  */
-	"ldr	r1, =running\n\t"
-	/* Update running.  */
-	"str	r0, [r1]\n\t"
-#if defined(__ARM_ARCH_6M__)
-	"cmp	r0, #0\n\t"
-	"beq	1f\n\t"
-#else
-	"cbz	r0, 1f\n\t"
-#endif
-	/**/
-	"add	r0, #20\n\t"
-	"ldm	r0!, {r4, r5, r6, r7}\n\t"
-#if defined(__ARM_ARCH_6M__)
-	"ldm	r0!, {r1, r2, r3}\n\t"
-	"mov	r8, r1\n\t"
-	"mov	r9, r2\n\t"
-	"mov	r10, r3\n\t"
-	"ldm	r0!, {r1, r2}\n\t"
-	"mov	r11, r1\n\t"
-	"msr	PSP, r2\n\t"
-#else
-	"ldr	r8, [r0], #4\n\t"
-	"ldr	r9, [r0], #4\n\t"
-	"ldr	r10, [r0], #4\n\t"
-	"ldr	r11, [r0], #4\n\t"
-	"ldr	r1, [r0], #4\n\t"
-	"msr	PSP, r1\n\t"
-#endif
-	"mov	r0, #0\n\t"
-	/* Unmask interrupts.  */
-#if defined(__ARM_ARCH_6M__)
-	"cpsie	i\n\t"
-#else
-	"msr	BASEPRI, r0\n\t"
-#endif
-	/**/
-	"sub	r0, #3\n\t" /* EXC_RETURN to a thread with PSP */
-	"bx	r0\n"
-    "1:\n\t"
-	/* Spawn an IDLE thread.  */
-	"ldr	r0, =__main_stack_end__-32\n\t"
-	"msr	PSP, r0\n\t"
-	"mov	r1, #0\n\t"
-	"mov	r2, #0\n\t"
-	"mov	r3, #0\n\t"
-	"stm	r0!, {r1, r2, r3}\n\t"
-	"stm	r0!, {r1, r2, r3}\n\t"
-	"ldr	r1, =chx_idle\n\t" /* PC = idle */
-	"mov	r2, #0x010\n\t"
-	"lsl	r2, r2, #20\n\t" /* xPSR = T-flag set (Thumb) */
-	"stm	r0!, {r1, r2}\n\t"
-	/**/
-	/* Unmask interrupts.  */
-	"mov	r0, #0\n\t"
-#if defined(__ARM_ARCH_6M__)
-	"cpsie	i\n\t"
-#else
-	"msr	BASEPRI, r0\n"
-#endif
-	/**/
-	"sub	r0, #3\n\t" /* EXC_RETURN to a thread with PSP */
-	"bx	r0"
-	: /* no output */ : "r" (tp_next) : "memory");
-}
 
 #if defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7EM__)
 /*
@@ -595,7 +549,7 @@ svc (void)
 
   asm ("ldr	r1, =running\n\t"
        "ldr	r1, [r1]\n\t"
-       "add	r1, #20\n\t"
+       "adds	r1, #20\n\t"
        /* Save registers onto CHX_THREAD struct.  */
        "stm	r1!, {r4, r5, r6, r7}\n\t"
        "mov	r2, r8\n\t"
@@ -605,14 +559,51 @@ svc (void)
        "mrs	r6, PSP\n\t" /* r13(=SP) in user space.  */
        "stm	r1!, {r2, r3, r4, r5, r6}\n\t"
        "ldr	r0, [r6]\n\t"
-       "sub	r1, #56\n\t"
+       "subs	r1, #56\n\t"
        "str	r1, [r6]"
        : "=r" (tp_next)
        : /* no input */
-       : "r1", "r2", "r3", "r4", "r5", "r6", "memory");
+       : "cc", "r1", "r2", "r3", "r4", "r5", "r6", "memory");
 
   asm volatile (
-	"b	.L_CONTEXT_SWITCH"
+	/* Now, r0 points to the thread to be switched.  */
+	/* Put it to *running.  */
+	"ldr	r1, =running\n\t"
+	/* Update running: chx_set_running */
+	"str	r0, [r1]\n\t"
+	"cbz	r0, 1f\n\t"
+	/**/
+	"adds	r0, #20\n\t"
+	"ldm	r0!, {r4, r5, r6, r7}\n\t"
+	"ldr	r8, [r0], #4\n\t"
+	"ldr	r9, [r0], #4\n\t"
+	"ldr	r10, [r0], #4\n\t"
+	"ldr	r11, [r0], #4\n\t"
+	"ldr	r1, [r0], #4\n\t"
+	"msr	PSP, r1\n\t"
+	/* Unmask interrupts.  */
+	"movs	r0, #0\n\t"
+	"msr	BASEPRI, r0\n\t"
+	"subs	r0, #3\n\t" /* EXC_RETURN to a thread with PSP */
+	"bx	r0\n"
+    "1:\n\t"
+	/* Spawn an IDLE thread.  */
+	"ldr	r0, =__main_stack_end__-32\n\t"
+	"msr	PSP, r0\n\t"
+	"movs	r1, #0\n\t"
+	"movs	r2, #0\n\t"
+	"movs	r3, #0\n\t"
+	"stm	r0!, {r1, r2, r3}\n\t"
+	"stm	r0!, {r1, r2, r3}\n\t"
+	"ldr	r1, =chx_idle\n\t" /* PC = idle */
+	"movs	r2, #0x010\n\t"
+	"lsls	r2, r2, #20\n\t" /* xPSR = T-flag set (Thumb) */
+	"stm	r0!, {r1, r2}\n\t"
+	/* Unmask interrupts.  */
+	"movs	r0, #0\n\t"
+	"msr	BASEPRI, r0\n"
+	"subs	r0, #3\n\t" /* EXC_RETURN to a thread with PSP */
+	"bx	r0"
 	: /* no output */ : "r" (tp_next) : "memory");
 }
 #endif

chopstx-gnu-linux.c

@@ -2,7 +2,7 @@
  * chopstx-gnu-linux.c - Threads and only threads: Arch specific code
  *                       for GNU/Linux emulation
  *
- * Copyright (C) 2017, 2018, 2019 Flying Stone Technology
+ * Copyright (C) 2017, 2018, 2019, 2021 Flying Stone Technology
  * Author: NIIBE Yutaka <gniibe@fsij.org>
  *
  * This file is a part of Chopstx, a thread library for embedded.
@@ -27,6 +27,16 @@
  *
  */
 
+/*
+ * NOTE: This code is not portable.  It's intended for GNU/Linux.
+ *
+ * This implementation depends on the feature of SA_SIGINFO of Linux,
+ * which signal handler takes three arguments.  Also, it depends on
+ * GNU C library for how to use the makecontext function on 64-bit
+ * machine.
+ *
+ */
+
 #include <unistd.h>
 #include <ucontext.h>
 #include <signal.h>
@@ -164,7 +174,13 @@ chx_idle (void)
       if (sig == SIGALRM)
 	tp_next = chx_timer_expired ();
       else
-	tp_next = chx_recv_irq (sig);
+	{
+	  tp_next = chx_recv_irq (sig);
+	  /* Exit when there is no waiter and it's INT or TERM.	 */
+	  if (tp_next == NULL
+	      && (sig == SIGINT || sig == SIGTERM))
+	    exit (1);
+	}
     }
 
   return tp_next;
@@ -260,14 +276,23 @@ preempted_context_switch (struct chx_thread *tp_next)
 static uintptr_t
 voluntary_context_switch (struct chx_thread *tp_next)
 {
-  struct chx_thread *tp, *tp_prev;
-
-  if (!tp_next)
-    tp_next = chx_idle ();
+  struct chx_thread *tp;
+  struct chx_thread *tp_prev;
 
   tp_prev = chx_running ();
-  chx_set_running (tp_next);
-  swapcontext (&tp_prev->tc, &tp_next->tc);
+  if (!tp_next)
+    {
+      chx_set_running (NULL);
+      tp_next = chx_idle ();
+      chx_set_running (tp_next);
+      if (tp_prev != tp_next)
+	swapcontext (&tp_prev->tc, &tp_next->tc);
+    }
+  else
+    {
+      chx_set_running (tp_next);
+      swapcontext (&tp_prev->tc, &tp_next->tc);
+    }
   chx_cpu_sched_unlock ();
 
   tp = chx_running ();
@@ -298,13 +323,22 @@ chopstx_create_arch (uintptr_t stack_addr, size_t stack_size,
    * signal blocked.  The sigmask will be cleared in chx_thread_start.
    */
   chx_cpu_sched_lock ();
+  memset (tp, 0, sizeof (struct chx_thread));
   getcontext (&tp->tc);
   tp->tc.uc_stack.ss_sp = (void *)stack_addr;
   tp->tc.uc_stack.ss_size = stack_size;
   tp->tc.uc_link = NULL;
 
+  /*
+   * makecontext is hard to use in a portable way, actually.
+   *
+   * On 64-bit machine, according to the standard, it should be coded
+   * to specify int (== 32-bit for LP64 machine) arguments that follow
+   * ARGC, so it is not that correct to specify two 64-bit arguments
+   * here.  However, GNU C library allows this.
+   */
   makecontext (&tp->tc, (void (*)(void))chx_thread_start,
-	       4, thread_entry, arg);
+	       2, thread_entry, arg);
   chx_cpu_sched_unlock ();
   return tp;
 }

chopstx-riscv32.c

@@ -2,7 +2,7 @@
  * chopstx-riscv32.c - Threads and only threads: Arch specific code
  *                     for RISC-V 32 IMAC (Bumblebee core)
  *
- * Copyright (C) 2019
+ * Copyright (C) 2019, 2021
  *               Flying Stone Technology
  * Author: NIIBE Yutaka <gniibe@fsij.org>
  *
@@ -514,7 +514,7 @@ voluntary_context_switch (struct chx_thread *tp_next)
 	 */
 	"# Call the IDLE function, interrupt masked.\n\t"
 	"mv	tp,zero\n\t"
-	"csrw	mscratch,tp\n\t"
+	"csrw	mscratch,tp\n\t" /* chx_set_running */
 	"la	sp,__main_stack_end__\n\t"
 	"call	chx_idle\n"
     ".L_V_CONTEXT_SWITCH_BEGIN:\n"
@@ -523,7 +523,7 @@ voluntary_context_switch (struct chx_thread *tp_next)
 	"mv	sp,%0\n\t"
 	RESTORE_CALLEE_SAVE_REGISTERS
 	/**/
-	"csrw	mscratch,sp\n\t"
+	"csrw	mscratch,sp\n\t" /* chx_set_running */
 	"lw	a0,0(sp)\n\t"
 	"beqz	a0,1f\n"
     ".L_RETURN_TO_PREEMPTED_THREAD:\n\t"
@@ -667,7 +667,7 @@ chx_handle_intr (void)
 	"mv	sp,%0\n\t"
 	RESTORE_CALLEE_SAVE_REGISTERS
 	/**/
-	"csrw	mscratch,sp\n\t"
+	"csrw	mscratch,sp\n\t" /* chx_set_running */
 	"lw	a0,0(sp)\n\t"
 	"bnez	a0,.L_RETURN_TO_PREEMPTED_THREAD\n\t"
 	/**/

chopstx.c

@@ -1,7 +1,7 @@
 /*
  * chopstx.c - Threads and only threads.
  *
- * Copyright (C) 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020
+ * Copyright (C) 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021
  *               Flying Stone Technology
  * Author: NIIBE Yutaka <gniibe@fsij.org>
  *
@@ -460,7 +460,7 @@ chx_recv_irq (uint32_t irq_num)
       break;
   chx_spin_unlock (&q_intr.lock);
 
-  if (p)
+  if (p != (struct chx_pq *)&q_intr.q)
     {
       struct chx_px *px = (struct chx_px *)p;
 
@@ -949,7 +949,9 @@ chopstx_mutex_lock (chopstx_mutex_t *mutex)
  * chopstx_mutex_unlock - Unlock the mutex
  * @mutex: Mutex
  *
- * Unlock @mutex.
+ * Unlock @mutex.  Note that Chopstx doesn't allow unlocking by
+ * non-owner of the lock.  chopstx_mutex_unlock should be called
+ * by a thread which did chopstx_mutex_lock.
  */
 void
 chopstx_mutex_unlock (chopstx_mutex_t *mutex)

contrib/ackbtn-gnu-linux.c

@@ -0,0 +1,232 @@
+/*
+ * ackbtn-gnu-linux.c - Acknowledge button support for GNU/Linux
+ *
+ * Copyright (C) 2021  Free Software Initiative of Japan
+ * Author: NIIBE Yutaka <gniibe@fsij.org>
+ *
+ * This file is a part of Chopstx, a thread library for embedded.
+ *
+ * Chopstx is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Chopstx is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * As additional permission under GNU GPL version 3 section 7, you may
+ * distribute non-source form of the Program without the copy of the
+ * GNU GPL normally required by section 4, provided you inform the
+ * recipients of GNU GPL by a written offer.
+ *
+ */
+
+#include <pthread.h>
+
+#include <unistd.h>
+
+#include <stdint.h>
+#include <string.h>
+#include <chopstx.h>
+
+#include <stdio.h>
+#include <signal.h>
+#include <sys/eventfd.h>
+#include <poll.h>
+#include <errno.h>
+#include <stdlib.h>
+
+static pthread_t tid_main;
+static pthread_t tid_ui;
+
+static pthread_mutex_t mutex;
+static pthread_cond_t cond;
+static int enabled;
+static int event_fd;
+
+static void
+ackbtn_intr (int signum, siginfo_t *siginfo, void *arg)
+{
+  extern void chx_sigmask (ucontext_t *uc);
+  extern void chx_handle_intr (int signum);
+
+  ucontext_t *uc = arg;
+  (void)signum;
+  (void)siginfo;
+  chx_handle_intr (SIGUSR2);
+  chx_sigmask (uc);
+}
+
+
+#define ACKBTN_ACKED   (1 << 0)
+#define ACKBTN_TIMEOUT (1 << 2)
+
+static void *
+user_interaction (void *arg)
+{
+  struct pollfd pollfds[2];
+
+  (void)arg;
+
+  pollfds[0].fd = 0;		/* standard input */
+  pollfds[0].events = POLLIN;
+
+  pollfds[1].fd = event_fd;
+  pollfds[1].events = POLLIN;
+
+  fputs ("User interaction thread for AckBtn started.\n", stdout);
+
+  while (1)
+    {
+      unsigned int acked_or_timeout = 0;
+      char buf[256];
+
+      pthread_mutex_lock (&mutex);
+      while (!enabled)
+	pthread_cond_wait (&cond, &mutex);
+      pthread_mutex_unlock (&mutex);
+
+      /* Consume all input if any.  */
+      while (1)
+	{
+	  int r;
+
+	  pollfds[0].revents = 0;
+
+	  r = poll (pollfds, 1, 0);
+	  if (r < 0)
+	    {
+	      if (errno == EINTR)
+		continue;
+
+	      perror ("poll");
+	      exit (1);
+	    }
+
+	  if (r == 0)
+	    break;
+
+	  if ((pollfds[0].revents & POLLIN))
+	    read (0, buf, sizeof buf);
+	}
+
+      fputs ("Type RET to acknowledge (or wait for timeout) > ", stdout);
+      fflush (stdout);
+
+      while (!acked_or_timeout)
+	{
+	  pollfds[0].revents = 0;
+	  pollfds[1].revents = 0;
+
+	  if (poll (pollfds, 2, -1) < 0)
+	    {
+	      if (errno == EINTR)
+		continue;
+
+	      perror ("poll");
+	      exit (1);
+	    }
+
+	  if ((pollfds[0].revents & POLLIN))
+	    {
+	      read (0, buf, sizeof buf);
+	      acked_or_timeout |= ACKBTN_ACKED;
+	    }
+
+	  if ((pollfds[1].revents & POLLIN))
+	    acked_or_timeout |= ACKBTN_TIMEOUT;
+	}
+
+      pthread_mutex_lock (&mutex);
+      if ((acked_or_timeout & ACKBTN_ACKED))
+	{
+	  if ((acked_or_timeout & ACKBTN_TIMEOUT))
+	    /* No output of newline, as it follows timeout message.  */
+	    fputs ("Input ignored", stdout);
+	  else
+	    {
+	      pthread_kill (tid_main, SIGUSR2);
+	      fputs ("Acknowledged\n", stdout);
+	    }
+	}
+
+      if ((acked_or_timeout & ACKBTN_TIMEOUT))
+	fputs ("\nTimeout\n", stdout);
+
+      while (enabled)
+	pthread_cond_wait (&cond, &mutex);
+
+      read (event_fd, buf, sizeof (uint64_t));
+      pthread_mutex_unlock (&mutex);
+    }
+}
+
+void
+ackbtn_init (chopstx_intr_t *intr)
+{
+  int r;
+  sigset_t sigset;
+  struct sigaction act;
+
+  event_fd = eventfd (0, EFD_CLOEXEC);
+  if (event_fd < 0)
+    {
+      perror ("eventfd");
+      exit (1);
+    }
+
+  pthread_mutex_init (&mutex, NULL);
+  pthread_cond_init (&cond, NULL);
+  enabled = 0;
+
+  sigemptyset (&sigset);
+  sigaddset (&sigset, SIGUSR2);
+  sigaddset (&sigset, SIGALRM);
+
+  tid_main = pthread_self ();
+
+  /* Launch the thread for user interaction.  */
+  pthread_sigmask (SIG_BLOCK, &sigset, NULL);
+
+  r = pthread_create (&tid_ui, NULL, user_interaction, NULL);
+  if (r)
+    {
+      fprintf (stderr, "ackbtn_init: %s\n", strerror (r));
+      exit (1);
+    }
+
+  act.sa_sigaction = ackbtn_intr;
+  sigfillset (&act.sa_mask);
+  act.sa_flags = SA_SIGINFO|SA_RESTART;
+  sigaction (SIGUSR2, &act, NULL);
+
+  pthread_sigmask (SIG_UNBLOCK, &sigset, NULL);
+
+  chopstx_claim_irq (intr, SIGUSR2);
+}
+
+void
+ackbtn_enable (void)
+{
+  pthread_mutex_lock (&mutex);
+  enabled = 1;
+  pthread_cond_signal (&cond);
+  pthread_mutex_unlock (&mutex);
+}
+
+void
+ackbtn_disable (void)
+{
+  const uint64_t l = 1;
+
+  pthread_mutex_lock (&mutex);
+  enabled = 0;
+  write (event_fd, &l, sizeof (l));
+  pthread_cond_signal (&cond);
+  pthread_mutex_unlock (&mutex);
+}

contrib/adc-gnu-linux.c

@@ -3,7 +3,7 @@
  *                   This ADC driver just fills pseudo random values.
  *                   It's completely useless other than for NeuG.
  *
- * Copyright (C) 2017  Free Software Initiative of Japan
+ * Copyright (C) 2017, 2021  Free Software Initiative of Japan
  * Author: NIIBE Yutaka <gniibe@fsij.org>
  *
  * This file is a part of Chopstx, a thread library for embedded.
@@ -33,7 +33,7 @@
 #include <chopstx.h>
 #include "adc.h"
 
-#define ADC_RANDOM_SEED 0x01034649 /* "Hello, father!" in Japanese */
+#include <sys/random.h>
 
 /*
  * Do calibration for ADC.
@@ -41,7 +41,6 @@
 int
 adc_init (void)
 {
-  srandom (ADC_RANDOM_SEED);
   return 0;
 }
 
@@ -55,8 +54,7 @@ uint32_t adc_buf[64];
 void
 adc_start_conversion (int offset, int count)
 {
-  while (count--)
-    adc_buf[offset++] = random ();
+  getrandom (adc_buf+offset, count, 0);
 }
 
 

doc/chopstx.texi

@@ -1,7 +1,7 @@
 \input texinfo                      @c -*-texinfo-*-
 @c %**start of header
 @setfilename chopstx.info
-@set VERSION 2.0
+@set VERSION 2.3
 @settitle Chopstx Reference Manual
 @c Unify some of the indices.
 @syncodeindex tp fn
@@ -11,7 +11,7 @@
 This manual is for Chopstx (version @value{VERSION}).
 
 @noindent
-Copyright @copyright{} 2013, 2015, 2016, 2017, 2018, 2019, 2020 Flying Stone Technology @*
+Copyright @copyright{} 2013, 2015, 2016, 2017, 2018, 2019, 2020, 2021 Flying Stone Technology @*
 
 @quotation
 Permission is granted to copy, distribute and/or modify this document
@@ -91,7 +91,7 @@ Indexes
 Chopstx is an RT thread library for ARM Cortex-M0, Cortex-M0plus,
 Cortex-M3, Cortex-M4 with no FPU or DSP, RISC-V Bumblebee, and
 GNU/Linux emulation.  Specifically, it is used for STM32F030, MKL27Z,
-STM32F103, GD32F103, STM32L432, GD32V103 and as a command on
+STM32F103, GD32F103, STM32L432, GD32VF103 and as a command on
 GNU/Linux.
 
 While most RTOSes come with many features, drivers, and stacks,
@@ -126,7 +126,7 @@ done by interrupt handler, bottom half, and thead is crucial for
 applications' performance.  And because the demarcation should be done
 at an early stage of an application development, it has a tendency,
 many parts are getting demanding higher priority.  Amount of code for
-higher priority interrupt hander is getting bigger and bigger, while
+higher priority interrupt handler is getting bigger and bigger, while
 losing performance.
 
 On the other hand, ``Threads (and only Threads)'' programming style
@@ -239,7 +239,7 @@ chx_handle_intr entries.
 Obviously, this is suboptimal.  It kills the hardware effort to
 decrease interrupt latency.
 
-I is certainly possible to support configurable vector table and/or
+It is certainly possible to support configurable vector table and/or
 better dispatch.
 
 The reason why I keep this badness is that I believe that when

entry-cortex-m.c

@@ -1,7 +1,7 @@
 /*
  * entry-cortex-m.c - Entry routine when reset and interrupt vectors.
  *
- * Copyright (C) 2013, 2014, 2015, 2016, 2017, 2019
+ * Copyright (C) 2013, 2014, 2015, 2016, 2017, 2019, 2021
  *               Flying Stone Technology
  * Author: NIIBE Yutaka <gniibe@fsij.org>
  *
@@ -65,23 +65,6 @@ extern uint8_t __main_stack_end__;
 extern void svc (void);
 #endif
 
-/*
- * In ARMv6-M Architecture Reference Manual and ARM v7-M Architecture
- * Reference Manual, you can find a section B1.5.12 for tail-chaining.
- *
- * B1.5.12 Exceptions on exception return, and tail-chaining exceptions
- */
-/*
- * Because it is tail-chained, the preempt function has an argument
- * with type of (struct chx_thread *), in fact.
- */
-extern void preempt (void);
-
-/*
- * Following functions return type of (struct chx_thread *) for
- * tail-chained function (the preempt function), for its argument.
- */
-extern void chx_timer_handler (void);
 extern void chx_handle_intr (void);
 
 static void nmi (void)
@@ -130,7 +113,7 @@ entry (void)
 {
   asm volatile ("bl	clock_init\n\t"
 		/* Clear BSS section.  */
-		"mov	r0, #0\n\t"
+		"movs	r0, #0\n\t"
 		"ldr	r1, =_bss_start\n\t"
 		"ldr	r2, =_bss_end\n"
 	"0:\n\t"
@@ -138,7 +121,7 @@ entry (void)
 		"beq	1f\n\t"
 #if defined(__ARM_ARCH_6M__)
 		"str	r0, [r1]\n\t"
-		"add	r1, #4\n\t"
+		"adds	r1, #4\n\t"
 #else
 		"str	r0, [r1], #4\n\t"
 #endif
@@ -154,8 +137,8 @@ entry (void)
 #if defined(__ARM_ARCH_6M__)
 		"ldr	r0, [r3]\n\t"
 		"str	r0, [r1]\n\t"
-		"add	r3, #4\n\t"
-		"add	r1, #4\n\t"
+		"adds	r3, #4\n\t"
+		"adds	r1, #4\n\t"
 #else
 		"ldr	r0, [r3], #4\n\t"
 		"str	r0, [r1], #4\n\t"
@@ -164,9 +147,9 @@ entry (void)
 	"3:\n\t"
 		/* Switch to PSP.  */
 		"ldr	r0, =__process0_stack_end__\n\t"
-		COMPOSE_STATEMENT ("sub	r0, #", CHOPSTX_THREAD_SIZE, "\n\t")
+		COMPOSE_STATEMENT ("subs	r0, #", CHOPSTX_THREAD_SIZE, "\n\t")
 		"msr	PSP, r0\n\t" /* Process (main routine) stack.  */
-		"mov	r1, #2\n\t"
+		"movs	r1, #2\n\t"
 		"msr	CONTROL, r1\n\t"
 		"isb\n\t"
 		"bl	chx_init\n\t"
@@ -174,7 +157,7 @@ entry (void)
 		"bl	gpio_init\n\t"
 		/* Enable interrupts.  */
 #if defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7EM__)
-		"mov	r0, #0\n\t"
+		"movs	r0, #0\n\t"
 		"msr	BASEPRI, r0\n\t"
 #endif
 		"cpsie	i\n\t"
@@ -208,8 +191,8 @@ handler vector_table[] __attribute__ ((section(".startup.vectors"))) = {
 #endif  
   none,				/* Debug */
   none,				/* reserved */
-  preempt,			/* PendSV */
-  chx_timer_handler,		/* SysTick */
+  none,				/* PendSV */
+  chx_handle_intr,		/* SysTick */
   /* 0x40 */
   chx_handle_intr /* WWDG */,      chx_handle_intr /* PVD */,
   chx_handle_intr /* TAMPER */,    chx_handle_intr /* RTC */,

example-cdc-gnu-linux/sample.c

@@ -179,7 +179,14 @@ main (int argc, const char *argv[])
 	      if (size < 0)
 		goto connection_loop;
 
-	      if (size == 1)
+	      if (size == 0)
+		/* Timeout */
+		{
+		  if (tty_send (tty, "\r\n", 2) < 0)
+		    return 0;
+		  break;
+		}
+	      else if (size == 1)
 		/* Do nothing but prompt again.  */
 		break;
 	      else if (size)

example-cdc-gnu-linux/usb-cdc.c

@@ -904,8 +904,18 @@ tty_recv (struct tty *t, char *buf, uint32_t *timeout)
       chopstx_mutex_lock (&t->mtx);
       r = check_rx (t);
       chopstx_mutex_unlock (&t->mtx);
-      if (r || (timeout != NULL && *timeout == 0))
+      if (r)
 	break;
+      else if (timeout != NULL && *timeout == 0)
+	{
+	  int i;
+
+	  /* Cancel the input.	*/
+	  for (i = 0; i < t->inputline_len; i++)
+	    tty_send (t, "\x08\x20\x08", 3);
+	  t->inputline_len = 0;
+	  break;
+	}
     }
 
   chopstx_mutex_lock (&t->mtx);

example-fsm-55/reset.c

@@ -1,7 +1,7 @@
 /*
  * reset.c - No system routines, but only RESET handler for STM32F030.
  *
- * Copyright (C) 2015 Flying Stone Technology
+ * Copyright (C) 2015, 2021 Flying Stone Technology
  * Author: NIIBE Yutaka <gniibe@fsij.org>
  *
  * Copying and distribution of this file, with or without modification,
@@ -19,10 +19,10 @@ reset (void)
 {
   asm volatile ("cpsid	i\n\t"		/* Mask all interrupts. */
 		"mov	r0, pc\n\t"	/* r0 = PC & ~0x0fff */
-		"mov	r1, #0x10\n\t"
-		"lsl	r1, #8\n\t"
-		"sub	r1, r1, #1\n\t"
-		"bic	r0, r0, r1\n\t"
+		"movs	r1, #0x10\n\t"
+		"lsls	r1, #8\n\t"
+		"subs	r1, #1\n\t"
+		"bics	r0, r0, r1\n\t"
 		"ldr	r2, [r0]\n\t"
 		"msr	MSP, r2\n\t"	/* Main (exception handler) stack. */
 		"b	entry\n\t"
@@ -31,8 +31,6 @@ reset (void)
 }
 
 extern uint8_t __main_stack_end__;
-extern void preempt (void);
-extern void chx_timer_handler (void);
 extern void chx_handle_intr (void);
 
 static void nmi (void)
@@ -84,8 +82,8 @@ handler vector[] __attribute__ ((section(".vectors"))) = {
   none,				/* SVCall */
   none,				/* Debug */
   none,				/* reserved */
-  preempt,			/* PendSV */
-  chx_timer_handler,		/* SysTick */
+  none,				/* PendSV */
+  chx_handle_intr,		/* SysTick */
   /* 0x40 */
   chx_handle_intr /* WWDG */,     chx_handle_intr /* PVD */,
   chx_handle_intr /* TAMPER */,   chx_handle_intr /* RTC */,

mcu/usb-usbip.c

@@ -1,7 +1,7 @@
 /*
  * usb-usbip.c - USB Device Emulation (server side) by USBIP
  *
- * Copyright (C) 2017, 2018  g10 Code GmbH
+ * Copyright (C) 2017, 2018, 2021  g10 Code GmbH
  * Author: NIIBE Yutaka <gniibe@fsij.org>
  *
  * This file is a part of Chopstx, a thread library for embedded.
@@ -22,10 +22,26 @@
  */
 
 /*
- FIXME:
-   RESET handling
-   USB Shutdown
-   Use reply structure of its own
+ * This driver is intended to emulate USB full-speed device, which
+ * maximum packet size is 64.
+ *
+ * "USBIP" is actually URB over network (instead of USB packet over
+ * network), and its (current) naive protocol may expose possible
+ * demarcation problem, which never occurs in real host-device; In
+ * real host-device relationship, it is host side, which does
+ * composition/decomposition of URB to/from packets.  In an
+ * implmentation of USB device with USBIP, it needs to be device side,
+ * which does composition/decomposition of URB to/from packets.
+ *
+ * In this implementation of USB driver, URB_DATA_SIZE is defined as
+ * (65544+10), because (major) target device intended is CCID.  In the
+ * CCID specification, you can find the value 65544+10.
+ */
+/*
+ *  FIXME:
+ *    RESET handling
+ *    USB Shutdown
+ *    Use reply structure of its own
  */
 
 #include <pthread.h>
@@ -96,7 +112,7 @@ struct urb {
   struct urb *next;
   struct urb *prev;
 
-  uint16_t remain;
+  uint32_t remain;
   char *data_p;
 
   pthread_t tid;
@@ -236,7 +252,67 @@ attach_device (char busid[32], size_t *len_p)
   return (const char *)&usbip_usb_device;
 }
 
-#define URB_DATA_SIZE 65535
+/*
+ * The number 65544 comes from ISO 7816-4, which defines data format
+ * of smartcard;  CLS INS P1 P2 occupies four octets.  Then, Lc-octet
+ * to represent size of command data block, then command data block.
+ * Lastly, Le-octet to represent size of response data block to be
+ * returned.
+ *
+ * /----- for CLS INS P1 P2
+ * |
+ * |   /-- for Lc
+ * |   |
+ * |   |   /-- for data block
+ * |   |   |
+ * |   |   |       /-- for Le
+ * |   |   |       |
+ * v   v   v       v
+ * 4 + 3 + 65535 + 2 = 65544
+ *
+ * The number 10 comes from the CCID protocol specification; It is the
+ * header size of CCID.  Besides, we can find the number 65544 in the
+ * CCID protocol specification, too.
+ *
+ * And... we have "AND ONE MORE" three times.
+ *
+ * We accept that, as Buddha did.
+ *
+ * There are different interpretations for the historical fact and the
+ * idiom.  Most likely, nowadays, here, third-time is considered a
+ * strikeout, perhaps, due to popularity of baseball.
+ */
+#define URB_DATA_SIZE (65544+10+1+1+1)
+
+/*
+ * The reasons why there are "+1" three times.
+ *
+ * Wrong (1): +1, because of confusion of data size maximum.
+ * Wrong (2): +1, because of confusion of the size for Le.
+ * Wrong (3): +1, because of keeping applying old patch.
+ *
+ * Something like this may occur, unfortunately, in our world.
+ *
+ * We need to consider the real case of the max buffer size for
+ * libusb_bulk_transfer with CCID (let us call this "CASE_MAX").
+ *
+ * (1) Although the data size maximum (for all cases) is 65536, it
+ * only occurs when Le size is zero.  In the particular case of
+ * CASE_MAX, it is actually 65535.  When just applying the max value
+ * 65536, +1 occurs.
+ *
+ * (2) Although maximum size to represent Le is 3, it only occurs when
+ * Lc size is zero.  In the particular case of CASE_MAX, it is
+ * actually 2.  When just applying the max value 3, +1 occurs.
+ *
+ * (3) Fedora keeps a old patch for Ominikey 3121.  The patch was
+ * written when the value of CMD_BUF_SIZE in libccid was small for
+ * short extended APDU exchange.  In the patch, it uses the value 11
+ * for the header size (instead of 10) of TPDU, for its special
+ * support.  Historically, CMD_BUF_SIZE in libccid was updated
+ * to bigger value to handle extended APDU exchange.  When just applying
+ * the old patch using 11, +1 occurs.
+ */
 
 struct usbip_msg_cmd {
   uint32_t devid;
@@ -299,12 +375,14 @@ static int write_data_transaction (struct usb_control *usbc_p,
 static int read_data_transaction (struct usb_control *usbc_p,
 				  int ep_num, char *buf, uint16_t count);
 
+#define USB_MAX_PACKET_SIZE 64 /* For USB fullspeed device.  */
+
 static int
 hc_handle_control_urb (struct urb *urb)
 {
   int r;
   uint16_t count;
-  uint16_t remain = urb->len;
+  uint32_t remain = urb->len;
   uint64_t l;
 
   if ((debug & DEBUG_USB))
@@ -325,10 +403,10 @@ hc_handle_control_urb (struct urb *urb)
 
       while (r == 0)
 	{
-	  if (remain > 64)
-	    count = 64;
+	  if (remain > USB_MAX_PACKET_SIZE)
+	    count = USB_MAX_PACKET_SIZE;
 	  else
-	    count = remain;
+	    count = (uint16_t)remain;
 
 	  read (usbc_ep0.eventfd, &l, sizeof (l));
 	  r = control_write_data_transaction (urb->data_p, count);
@@ -337,7 +415,7 @@ hc_handle_control_urb (struct urb *urb)
 
 	  urb->data_p += count;
 	  remain -= count;
-	  if (count < 64)
+	  if (count < USB_MAX_PACKET_SIZE)
 	    break;
 	}
       if (r >= 0)
@@ -353,10 +431,10 @@ hc_handle_control_urb (struct urb *urb)
 
       while (1)
 	{
-	  if (remain > 64)
-	    count = 64;
+	  if (remain > USB_MAX_PACKET_SIZE)
+	    count = USB_MAX_PACKET_SIZE;
 	  else
-	    count = remain;
+	    count = (uint16_t)remain;
 
 	  read (usbc_ep0.eventfd, &l, sizeof (l));
 	  r = control_read_data_transaction (urb->data_p, count);
@@ -368,7 +446,7 @@ hc_handle_control_urb (struct urb *urb)
 
 	  remain -= r;
 	  urb->data_p += r;
-	  if (r < 64)
+	  if (r < USB_MAX_PACKET_SIZE)
 	    break;
 	}
 
@@ -516,10 +594,10 @@ hc_handle_data_urb (struct usb_control *usbc_p)
   if ((debug & DEBUG_USB))
     puts ("hc_hdu 0");
 
-  if (urb->remain > 64)
-    count = 64;
+  if (urb->remain > USB_MAX_PACKET_SIZE)
+    count = USB_MAX_PACKET_SIZE;
   else
-    count = urb->remain;
+    count = (uint16_t)urb->remain;
 
   if (urb->dir == USBIP_DIR_OUT)
     {				/* Output from host to device.  */
@@ -533,7 +611,7 @@ hc_handle_data_urb (struct usb_control *usbc_p)
       urb->data_p += count;
       urb->remain -= count;
 
-      if (urb->remain == 0 || count < 64)
+      if (urb->remain == 0 || count < USB_MAX_PACKET_SIZE)
 	{
 	  size_t len = urb->len - urb->remain;
 
@@ -565,7 +643,7 @@ hc_handle_data_urb (struct usb_control *usbc_p)
 
       urb->remain -= r;
       urb->data_p += r;
-      if (urb->remain == 0 || r < 64)
+      if (urb->remain == 0 || r < USB_MAX_PACKET_SIZE)
 	{
 	  size_t len = urb->len - urb->remain;
 
@@ -596,7 +674,7 @@ issue_get_desc (void)
 {
   struct urb *urb;
 
-  urb = malloc (sizeof (struct urb) + 64);
+  urb = malloc (sizeof (struct urb) + USB_MAX_PACKET_SIZE);
 
   urb->next = urb->prev = urb;
 
@@ -606,14 +684,14 @@ issue_get_desc (void)
   urb->setup[3] = 1;			 /* Value H: desc_type */
   urb->setup[4] = 0;              	 /* Index */
   urb->setup[5] = 0;
-  urb->setup[6] = 64;		         /* Length */
+  urb->setup[6] = USB_MAX_PACKET_SIZE;   /* Length */
   urb->setup[7] = 0;
   urb->data_p = urb->data;
   urb->seq = 0;
   urb->devid = 0;
   urb->dir = USBIP_DIR_IN;
   urb->ep = 0;
-  urb->remain = urb->len = 64;
+  urb->remain = urb->len = USB_MAX_PACKET_SIZE;
   hc_handle_control_urb (urb);
   return urb;
 }
@@ -729,7 +807,7 @@ usbip_handle_urb (uint32_t seq)
 
  leave:
   msg.cmd = htonl (REP_URB_SUBMIT);
-  msg.seq = htonl (urb->seq);
+  msg.seq = htonl (seq);
 
   memset (&msg_rep, 0, sizeof (msg_rep));
   msg_rep.status = htonl (r);
@@ -1080,6 +1158,11 @@ usbip_run_server (void *arg)
       exit (1);
     }
 
+  fputs ("USBIP thread started.\n", stdout);
+  fputs ("You can use this by attaching following commands:\n", stdout);
+  fputs ("    # modprobe vhci_hcd\n", stdout);
+  fputs ("    # usbip attach -r 127.0.0.1 -b 1-1\n", stdout);
+
   pollfds[1].fd = shutdown_notify_fd;
   pollfds[1].events = POLLIN;
   pollfds[1].revents = 0;

rules.mk

@@ -71,7 +71,7 @@ MCFLAGS   = -march=rv32imac -mabi=ilp32
 LDFLAGS   = $(MCFLAGS) -nodefaultlibs -nostartfiles -lc -T$(LDSCRIPT) \
             -Wl,-Map=$(BUILDDIR)/$(PROJECT).map,--cref,--no-warn-mismatch
 else
-MCFLAGS   = -mcpu=$(MCU)
+MCFLAGS   = -mcpu=$(MCU) -masm-syntax-unified
 LDFLAGS   = $(MCFLAGS) -nostartfiles -T$(LDSCRIPT) \
             -Wl,-Map=$(BUILDDIR)/$(PROJECT).map,--cref,--no-warn-mismatch,--gc-sections
 endif