@@ -501,6 +501,15 @@ config DEBUG_UART_MT7620
driver will be available until the real driver model serial is
running.
+config DEBUG_UART_XTENSA_SEMIHOSTING
+ bool "Xtensa semihosting"
+ depends on XTENSA_SEMIHOSTING_SERIAL
+ help
+ Select this to enable the debug UART using the Xtensa semihosting driver.
+ This provides basic serial output from the console without needing to
+ start up driver model. The driver will be available until the real
+ driver model serial is running.
+
endchoice
config DEBUG_UART_BASE
@@ -936,7 +945,6 @@ config SH_SCIF_CLK_FREQ
config SEMIHOSTING_SERIAL
bool "Semihosting UART support"
depends on SEMIHOSTING && !SERIAL_RX_BUFFER
- imply SERIAL_PUTS
help
Select this to enable a serial UART using semihosting. Special halt
instructions will be issued which an external debugger (such as a
@@ -1115,6 +1123,14 @@ config XEN_SERIAL
If built without DM support, then requires Xen
to be built with CONFIG_VERBOSE_DEBUG.
+config XTENSA_SEMIHOSTING_SERIAL
+ bool "Xtensa Semihosting UART support"
+ depends on DM_SERIAL
+ depends on XTENSA_SEMIHOSTING
+ imply SERIAL_PUTS
+ help
+ Select this to enable a serial UART using Xtensa semihosting.
+
choice
prompt "Console port"
default 8xx_CONS_SMC1
@@ -60,6 +60,7 @@ obj-$(CONFIG_MT7620_SERIAL) += serial_mt7620.o
obj-$(CONFIG_HTIF_CONSOLE) += serial_htif.o
obj-$(CONFIG_SIFIVE_SERIAL) += serial_sifive.o
obj-$(CONFIG_XEN_SERIAL) += serial_xen.o
+obj-$(CONFIG_XTENSA_SEMIHOSTING_SERIAL) += serial_xtensa_semihosting.o
obj-$(CONFIG_S5P4418_PL011_SERIAL) += serial_s5p4418_pl011.o
ifndef CONFIG_SPL_BUILD
new file mode 100644
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2024 Jiaxun Yang <jiaxun.yang@flygoat.com>
+ */
+
+#include <dm.h>
+#include <malloc.h>
+#include <serial.h>
+
+#include <asm/platform/simcall.h>
+
+/**
+ * struct simc_serial_priv - Semihosting serial private data
+ * @counter: Counter used to fake pending every other call
+ */
+struct simc_serial_priv {
+ unsigned int counter;
+};
+
+static int simc_serial_getc(struct udevice *dev)
+{
+ char ch = 0;
+
+ simc_read(0, &ch, sizeof(ch));
+
+ return ch;
+}
+
+static int simc_serial_putc(struct udevice *dev, const char ch)
+{
+ char str[2] = {0};
+
+ str[0] = ch;
+ simc_write(1, str, 1);
+
+ return 0;
+}
+
+static int simc_serial_pending(struct udevice *dev, bool input)
+{
+ struct simc_serial_priv *priv = dev_get_priv(dev);
+
+ if (input) {
+ int res = simc_poll(0);
+ return res < 0 ? priv->counter++ & 1 : res;
+ }
+
+ return false;
+}
+
+static ssize_t smh_serial_puts(struct udevice *dev, const char *s, size_t len)
+{
+ int ret;
+
+ ret = simc_write(1, s, len);
+
+ return ret;
+}
+
+static const struct dm_serial_ops simc_serial_ops = {
+ .putc = simc_serial_putc,
+ .puts = smh_serial_puts,
+ .getc = simc_serial_getc,
+ .pending = simc_serial_pending,
+};
+
+U_BOOT_DRIVER(simc_serial) = {
+ .name = "serial_xtensa_semihosting",
+ .id = UCLASS_SERIAL,
+ .priv_auto = sizeof(struct simc_serial_priv),
+ .ops = &simc_serial_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+};
+
+U_BOOT_DRVINFO(simc_serial) = {
+ .name = "serial_xtensa_semihosting",
+};
+
+#if CONFIG_IS_ENABLED(DEBUG_UART_XTENSA_SEMIHOSTING)
+#include <debug_uart.h>
+
+static inline void _debug_uart_init(void)
+{
+}
+
+static inline void _debug_uart_putc(int c)
+{
+ simc_serial_putc(NULL, c);
+}
+
+DEBUG_UART_FUNCS
+#endif
Add xtensa semihosting driver. It can't use regular semihosting driver as Xtensa's has it's own semihosting ABI. Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> --- v2: - Fix simc_serial_pending implementation - Get puts work --- drivers/serial/Kconfig | 18 +++++- drivers/serial/Makefile | 1 + drivers/serial/serial_xtensa_semihosting.c | 92 ++++++++++++++++++++++++++++++ 3 files changed, 110 insertions(+), 1 deletion(-)