[console] Allow usage to be defined independently for each console

Add the concept of a "console usage", such as "standard output" or
"debug messages".  Allow usages to be associated with each console
independently.  For example, to send debugging output via the serial
port, while preventing it from appearing on the local console:

  #define CONSOLE_SERIAL CONSOLE_USAGE_ALL
  #define CONSOLE_PCBIOS ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_DEBUG )

If no usages are explicitly specified, then a default set of usages
will be applied.  For example:

  #define CONSOLE_SERIAL

will have the same affect as

  #define CONSOLE_SERIAL CONSOLE_USAGE_ALL

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/src/interface/linux/linux_console.c b/src/interface/linux/linux_console.c
index aeb7c661..c79e5263 100644
--- a/src/interface/linux/linux_console.c
+++ b/src/interface/linux/linux_console.c
@@ -33,6 +33,14 @@ FILE_LICENCE(GPL2_OR_LATER);
 #include <linux/termios.h>
 #include <asm/errno.h>
 
+#include <config/console.h>
+
+/* Set default console usage if applicable */
+#if ! ( defined ( CONSOLE_LINUX ) && CONSOLE_EXPLICIT ( CONSOLE_LINUX ) )
+#undef CONSOLE_LINUX
+#define CONSOLE_LINUX CONSOLE_USAGE_ALL
+#endif
+
 static void linux_console_putchar(int c)
 {
 	/* write to stdout */
@@ -79,6 +87,7 @@ struct console_driver linux_console __console_driver = {
 	.putchar = linux_console_putchar,
 	.getchar = linux_console_getchar,
 	.iskey = linux_console_iskey,
+	.usage = CONSOLE_LINUX,
 };
 
 static int linux_tcgetattr(int fd, struct termios *termios_p)