[console][io] Add an optional global input queue.

In this model, getc reads from a global input buffer and the uart posts data to this buffer.

This commit also enables the global input queue for STM32F7 and QEMU-Virt.

Tested on STM32F7/Dartuino and QEMU-ARM A15 with both CONSOLE_HAS_INPUT_BUFFER=1 and CONSOLE_HAS_INPUT_BUFFER=0

4 files changed, 33 insertions, 13 deletions

diff --git a/platform/qemu-virt/rules.mk b/platform/qemu-virt/rules.mk
index a19fdddd..fd588d15 100644
--- a/platform/qemu-virt/rules.mk
+++ b/platform/qemu-virt/rules.mk
@@ -37,7 +37,8 @@ MODULE_DEPS += \
 GLOBAL_DEFINES += \
     MEMBASE=$(MEMBASE) \
     MEMSIZE=$(MEMSIZE) \
-    PLATFORM_SUPPORTS_PANIC_SHELL=1
+    PLATFORM_SUPPORTS_PANIC_SHELL=1 \
+    CONSOLE_HAS_INPUT_BUFFER=1
 
 GLOBAL_DEFINES += MMU_WITH_TRAMPOLINE=1 \
 
diff --git a/platform/qemu-virt/uart.c b/platform/qemu-virt/uart.c
index b39e186e..4eebe102 100644
--- a/platform/qemu-virt/uart.c
+++ b/platform/qemu-virt/uart.c
@@ -28,6 +28,7 @@
 #include <platform/interrupts.h>
 #include <platform/debug.h>
 #include <platform/qemu-virt.h>
+#include <target/debugconfig.h>
 
 /* PL011 implementation */
 #define UART_DR    (0x00)
@@ -75,15 +76,23 @@ static enum handler_return uart_irq(void *arg)
 
         /* while fifo is not empty, read chars out of it */
         while ((UARTREG(base, UART_TFR) & (1<<4)) == 0) {
-            /* if we're out of rx buffer, mask the irq instead of handling it */
-            if (cbuf_space_avail(rxbuf) == 0) {
-                UARTREG(base, UART_IMSC) &= ~(1<<4); // !rxim
-                break;
+#if CONSOLE_HAS_INPUT_BUFFER
+            if (port == DEBUG_UART) {
+                char c = UARTREG(base, UART_DR);
+                cbuf_write_char(&console_input_cbuf, c, false);
+            } else
+#endif
+            {
+                /* if we're out of rx buffer, mask the irq instead of handling it */
+                if (cbuf_space_avail(rxbuf) == 0) {
+                    UARTREG(base, UART_IMSC) &= ~(1<<4); // !rxim
+                    break;
+                }
+
+                char c = UARTREG(base, UART_DR);
+                cbuf_write_char(rxbuf, c, false);
             }
 
-            char c = UARTREG(base, UART_DR);
-            cbuf_write_char(rxbuf, c, false);
-
             resched = true;
         }
     }
diff --git a/platform/stm32f7xx/rules.mk b/platform/stm32f7xx/rules.mk
index f040a492..27c033cd 100644
--- a/platform/stm32f7xx/rules.mk
+++ b/platform/stm32f7xx/rules.mk
@@ -34,7 +34,8 @@ LK_HEAP_IMPLEMENTATION ?= miniheap
 
 GLOBAL_DEFINES += \
 	PLATFORM_SUPPORTS_PANIC_SHELL=1 \
-    NOVM_MAX_ARENAS=2
+    NOVM_MAX_ARENAS=2 \
+    CONSOLE_HAS_INPUT_BUFFER=1
 
 MODULE_SRCS += \
 	$(LOCAL_DIR)/debug.c \
diff --git a/platform/stm32f7xx/uart.c b/platform/stm32f7xx/uart.c
index 33d86600..257cc3ec 100644
--- a/platform/stm32f7xx/uart.c
+++ b/platform/stm32f7xx/uart.c
@@ -161,7 +161,7 @@ void uart_init(void)
 #endif
 }
 
-static void stm32_usart_shared_irq(struct uart_instance *u)
+static void stm32_usart_shared_irq(struct uart_instance *u, const unsigned int id)
 {
     bool resched = false;
 
@@ -200,7 +200,16 @@ static void stm32_usart_shared_irq(struct uart_instance *u)
 
         /* we got a character */
         uint8_t c = (uint8_t)(u->handle.Instance->RDR & 0xff);
-        if (cbuf_write_char(&u->rx_buf, c, false) != 1) {
+
+        cbuf_t *target_buf = &u->rx_buf;
+
+#if CONSOLE_HAS_INPUT_BUFFER
+        if (id == DEBUG_UART) {
+            target_buf = &console_input_cbuf;
+        }
+#endif
+
+        if (cbuf_write_char(target_buf, c, false) != 1) {
             printf("WARNING: uart cbuf overrun!\n");
         }
         resched = true;
@@ -225,14 +234,14 @@ static void stm32_usart_shared_irq(struct uart_instance *u)
 #if ENABLE_UART1
 void stm32_USART1_IRQ(void)
 {
-    stm32_usart_shared_irq(uart[1]);
+    stm32_usart_shared_irq(uart[1], 1);
 }
 #endif
 
 #if ENABLE_UART3
 void stm32_USART3_IRQ(void)
 {
-    stm32_usart_shared_irq(uart[3]);
+    stm32_usart_shared_irq(uart[3], 3);
 }
 #endif