[comboot] Avoid dragging in serial console support unconditionally

When the ability for iPXE to handle multiple serial ports was added,
the choice was made that the singular serial port referred to by
COMBOOT calls should mean the port used for the serial console.  This
unintentionally caused IMAGE_COMBOOT to also enable CONSOLE_SERIAL.

Fix by providing a weak-symbol version of the serial console which
will be used if serial console support was not explicitly enabled.

Reported-by: Torgeir Wulfsberg <Torgeir.Wulfsberg@kongsberg.com>
Reported-by: Ján ONDREJ (SAL) <ondrejj@salstar.sk>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/arch/i386/interface/syslinux/comboot_call.c b/src/arch/i386/interface/syslinux/comboot_call.c
index 430bc3a380f1b8eb9d8fbb0547de393ae21c5c50..69d94c407ad3652bdd583a33b2fa8151bdbb1788 100644 (file)
--- a/src/arch/i386/interface/syslinux/comboot_call.c
+++ b/src/arch/i386/interface/syslinux/comboot_call.c
@@ -84,7 +84,6 @@ rmjmp_buf comboot_return;
 /* Mode flags set by INT 22h AX=0017h */
 static uint16_t comboot_graphics_mode = 0;
 
-
 /**
  * Print a string with a particular terminator
  */
@@ -713,3 +712,6 @@ void unhook_comboot_interrupts ( ) {
        unhook_bios_interrupt ( 0x22, ( unsigned int ) int22_wrapper,
                                &int22_vector );
 }
+
+/* Avoid dragging in serial console support unconditionally */
+struct uart serial_console __attribute__ (( weak ));