From 4f25c287d206289a92a3ac588e4d4cfa5557f298 Mon Sep 17 00:00:00 2001
From: yinshengkai <yinshengkai@xiaomi.com>
Date: Mon, 21 Aug 2023 11:33:01 +0800
Subject: [PATCH] arch/sim: add sim uart_ram support

Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>
---
 arch/sim/Kconfig            | 49 +++++++++++++++++++++++++++++++++++++
 arch/sim/src/sim/sim_uart.c | 41 +++++++++++++++++++++++++++++++
 2 files changed, 90 insertions(+)

diff --git a/arch/sim/Kconfig b/arch/sim/Kconfig
index c55d729f1d..05d379f627 100644
--- a/arch/sim/Kconfig
+++ b/arch/sim/Kconfig
@@ -625,6 +625,55 @@ config SIM_UART3_NAME
 		A UART port must also exist on the host system
 		with the exact same name specified here.
 
+config SIM_RAM_UART
+	bool "SIM RAM UART Device"
+	depends on RAM_UART
+	default n
+	---help---
+		SIM RAM UART. It emulates a UART device but using a RAM memory
+		instead a physical peripheral.
+
+if SIM_RAM_UART
+config SIM_RAM_UART0
+	bool "SIM RAM UART Device 0"
+	default n
+	---help---
+		sim ram uart device 0
+
+config SIM_RAM_UART0_SLAVE
+	bool "SIM_RAM_UART0 is slave"
+	depends on SIM_RAM_UART0
+	default n
+	---help---
+		The sim ram uart0 is slave
+
+config SIM_RAM_UART1
+	bool "SIM RAM UART Device 1"
+	default n
+	---help---
+		sim ram uart device 1
+
+config SIM_RAM_UART1_SLAVE
+	bool "SIM_RAM_UART1 is slave"
+	depends on SIM_RAM_UART1
+	default n
+	---help---
+		The sim ram uart1 is slave
+
+config SIM_RAM_UART2
+	bool "SIM RAM UART Device 2"
+	default n
+	---help---
+		sim ram uart device 2
+
+config SIM_RAM_UART2_SLAVE
+	bool "SIM_RAM_UART2 is slave"
+	depends on SIM_RAM_UART2
+	default n
+	---help---
+		The sim ram uart2 is slave
+endif
+
 endmenu
 
 config SIM_USB_DEV
diff --git a/arch/sim/src/sim/sim_uart.c b/arch/sim/src/sim/sim_uart.c
index fbd42a6e41..2d4b04bb3a 100644
--- a/arch/sim/src/sim/sim_uart.c
+++ b/arch/sim/src/sim/sim_uart.c
@@ -25,7 +25,9 @@
 #include <nuttx/config.h>
 #include <nuttx/serial/serial.h>
 #include <nuttx/fs/ioctl.h>
+#include <nuttx/serial/uart_ram.h>
 #include <nuttx/wqueue.h>
+#include <string.h>
 #include <sys/types.h>
 #include <fcntl.h>
 #include <errno.h>
@@ -666,6 +668,21 @@ static bool tty_txempty(struct uart_dev_s *dev)
 }
 #endif
 
+#ifdef CONFIG_SIM_RAM_UART
+static int sim_uartram_register(FAR const char *devname, bool slave)
+{
+  char name[NAME_MAX];
+  FAR struct uart_rambuf_s *shmem;
+
+  strlcpy(name, strrchr(devname, '/') + 1, NAME_MAX);
+  shmem = host_allocshmem(name, sizeof(struct uart_rambuf_s) * 2, !slave);
+  DEBUGASSERT(shmem);
+
+  memset(shmem, 0, sizeof(struct uart_rambuf_s) * 2);
+  return uart_ram_register(devname, shmem, slave);
+}
+#endif
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -676,6 +693,30 @@ static bool tty_txempty(struct uart_dev_s *dev)
 
 void sim_uartinit(void)
 {
+#ifdef CONFIG_SIM_RAM_UART0
+#  ifdef CONFIG_SIM_RAM_UART0_SLAVE
+  sim_uartram_register("/dev/ttyVS0", true);
+#  else
+  sim_uartram_register("/dev/ttyVS0", false);
+#  endif
+#endif
+
+#ifdef CONFIG_SIM_RAM_UART1
+#  ifdef CONFIG_SIM_RAM_UART1_SLAVE
+  sim_uartram_register("/dev/ttyVS1", true);
+#  else
+  sim_uartram_register("/dev/ttyVS1", false);
+#  endif
+#endif
+
+#ifdef CONFIG_SIM_RAM_UART2
+#  ifdef CONFIG_SIM_RAM_UART2_SLAVE
+  sim_uartram_register("/dev/ttyVS2", true);
+#  else
+  sim_uartram_register("/dev/ttyVS2", false);
+#  endif
+#endif
+
 #ifdef USE_DEVCONSOLE
   /* Start the simulated UART device */