Feat: Add uart support

src/target/common/include/target/uart.h

@@ -7,5 +7,94 @@
 #pragma once
 
 #include <stdint.h>
+#include <stdbool.h>
+#include "soc_caps.h"
 
+/**
+ * @brief UART port numbers
+ *
+ * Available UART ports depend on the chip's SOC_UART_HP_NUM capability.
+ */
+typedef enum {
+    UART_NUM_0,                         /*!< UART port 0 */
+    UART_NUM_1,                         /*!< UART port 1 */
+#if SOC_UART_HP_NUM > 2
+    UART_NUM_2,                         /*!< UART port 2 */
+#endif
+#if SOC_UART_HP_NUM > 3
+    UART_NUM_3,                         /*!< UART port 3 */
+#endif
+#if SOC_UART_HP_NUM > 4
+    UART_NUM_4,                         /*!< UART port 4 */
+#endif
+    UART_NUM_MAX,                       /*!< UART port max */
+} uart_port_t;
+
+#define UART_INTR_RXFIFO_FULL      (0x1<<0)
+#define UART_INTR_RXFIFO_TOUT      (0x1<<8)
+
+/**
+ * @brief Initialize UART
+ *
+ * @param uart_num UART port number
+ * @param baudrate Baud rate
+ */
 void stub_target_uart_init(uint8_t uart_num, uint32_t baudrate);
+
+/**
+ * @brief Set UART baud rate
+ *
+ * @param uart_num UART port number
+ * @param baudrate Baud rate
+ */
+void stub_target_uart_set_baudrate(uint8_t uart_num, uint32_t baudrate);
+
+/**
+ * @brief Attach interrupt handler to UART and configure interrupts
+ *
+ * @param uart_num UART port number
+ * @param intr_num CPU interrupt source
+ * @param handler Interrupt handler function pointer
+ * @param flags Interrupt enable flags (bitwise OR of UART_INTR_* values)
+ */
+void stub_target_uart_intr_attach(uint8_t uart_num, int intr_num, void *handler, uint32_t flags);
+
+/**
+ * @brief Get and clear UART interrupt status
+ *
+ * This function returns the interrupt status and automatically clears it.
+ * Call this at the beginning of your interrupt handler.
+ *
+ * @param uart_num UART port number
+ * @return Bitmask of active interrupts that were cleared
+ */
+uint32_t stub_target_uart_get_intr_flags(uint8_t uart_num);
+
+/**
+ * @brief Get number of bytes available in RX FIFO
+ *
+ * @param uart_num UART port number
+ * @return Number of bytes currently in the RX FIFO
+ */
+uint32_t stub_target_uart_get_rxfifo_count(uint8_t uart_num);
+
+/**
+ * @brief Read a single byte from UART RX FIFO
+ *
+ * This function reads one byte from the RX FIFO without checking
+ * if data is available. Call stub_target_uart_get_rxfifo_count()
+ * first to ensure data is available.
+ *
+ * @param uart_num UART port number
+ * @return The byte read from the FIFO
+ */
+uint8_t stub_target_uart_read_rxfifo_byte(uint8_t uart_num);
+
+/**
+ * @brief Configure RX timeout threshold
+ *
+ * @param uart_num UART port number
+ * @param timeout Timeout value in bit times (1-126, 0 to disable)
+ * timeout mean the multiple of UART packets (~11 bytes) that can be received before timeout
+ */
+void stub_target_uart_set_rx_timeout(uint8_t uart_num, uint8_t timeout);

src/target/esp32/CMakeLists.txt

@@ -13,6 +13,7 @@ target_include_directories(${ESP_TARGET_LIB}
 
 target_link_options(${ESP_TARGET_LIB}
     PUBLIC -T${CMAKE_CURRENT_LIST_DIR}/ld/esp32.rom.ld
+    PUBLIC -T${CMAKE_CURRENT_LIST_DIR}/ld/esp32.rom.redefined.ld
     PUBLIC -T${CMAKE_CURRENT_LIST_DIR}/ld/esp32.rom.libc-funcs.ld
     PUBLIC -T${CMAKE_CURRENT_LIST_DIR}/ld/esp32.rom.libgcc.ld
 )