By using a hypervisor call, we can implement DEBUG_UART on xen. This will allow us to see messages even earlier than serial_init().
Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org --- drivers/serial/Kconfig | 14 +++++++++++--- drivers/serial/serial_xen.c | 20 ++++++++++++++++++++ 2 files changed, 31 insertions(+), 3 deletions(-)
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index e344677f91f6..536cf0641773 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -401,11 +401,19 @@ config DEBUG_UART_MTK driver will be available until the real driver model serial is running.
+config DEBUG_UART_XEN + bool "XEN Hypervisor Console" + depends on XEN_SERIAL + help + Select this to enable a debug UART using the serial_xen driver. You + will not have to provide any parameters to make this work. The driver + will be available until the real driver-model serial is running. + endchoice
config DEBUG_UART_BASE hex "Base address of UART" - depends on DEBUG_UART + depends on DEBUG_UART && !DEBUG_UART_XEN default 0 if DEBUG_UART_SANDBOX help This is the base address of your UART for memory-mapped UARTs. @@ -415,7 +423,7 @@ config DEBUG_UART_BASE
config DEBUG_UART_CLOCK int "UART input clock" - depends on DEBUG_UART + depends on DEBUG_UART && !DEBUG_UART_XEN default 0 if DEBUG_UART_SANDBOX help The UART input clock determines the speed of the internal UART @@ -427,7 +435,7 @@ config DEBUG_UART_CLOCK
config DEBUG_UART_SHIFT int "UART register shift" - depends on DEBUG_UART + depends on DEBUG_UART && !DEBUG_UART_XEN default 0 if DEBUG_UART help Some UARTs (notably ns16550) support different register layouts diff --git a/drivers/serial/serial_xen.c b/drivers/serial/serial_xen.c index ed191829f059..34c90ece40fc 100644 --- a/drivers/serial/serial_xen.c +++ b/drivers/serial/serial_xen.c @@ -5,6 +5,7 @@ */ #include <common.h> #include <cpu_func.h> +#include <debug_uart.h> #include <dm.h> #include <serial.h> #include <watchdog.h> @@ -15,11 +16,14 @@ #include <xen/events.h>
#include <xen/interface/sched.h> +#include <xen/interface/xen.h> #include <xen/interface/hvm/hvm_op.h> #include <xen/interface/hvm/params.h> #include <xen/interface/io/console.h> #include <xen/interface/io/ring.h>
+#include <asm/xen/hypercall.h> + DECLARE_GLOBAL_DATA_PTR;
u32 console_evtchn; @@ -178,3 +182,19 @@ U_BOOT_DRIVER(serial_xen) = { .flags = DM_FLAG_PRE_RELOC, };
+#if defined(CONFIG_DEBUG_UART_XEN) +static inline void _debug_uart_init(void) {} + +static inline void _debug_uart_putc(int c) +{ +#if CONFIG_IS_ENABLED(ARM) + xen_debug_putc(c); +#else + /* the type cast should work on LE only */ + HYPERVISOR_console_io(CONSOLEIO_write, 1, (char *)&ch); +#endif +} + +DEBUG_UART_FUNCS + +#endif