[console] Add facility for rudimentary keyboard mapping

Allow for remapping of ASCII characters returned by the BIOS, using a
map consisting of (from,to) pairs.

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

diff --git a/src/arch/i386/firmware/pcbios/bios_console.c b/src/arch/i386/firmware/pcbios/bios_console.c
index 55ab21bbb818d9022fdc523f7f7c49ce750a7713..1ecd07dddeb59d2d28b77503c509d76d23801353 100644 (file)
--- a/src/arch/i386/firmware/pcbios/bios_console.c
+++ b/src/arch/i386/firmware/pcbios/bios_console.c
@@ -22,6 +22,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <realmode.h>
 #include <ipxe/console.h>
 #include <ipxe/ansiesc.h>
+#include <ipxe/keymap.h>
 
 #define ATTR_BOLD              0x08
 
@@ -228,6 +229,22 @@ static const char * scancode_to_ansi_seq ( unsigned int scancode ) {
        return NULL;
 }
 
+/**
+ * Map a key
+ *
+ * @v character                Character read from console
+ * @ret character      Mapped character
+ */
+static int bios_keymap ( unsigned int character ) {
+       struct key_mapping *mapping;
+
+       for_each_table_entry ( mapping, KEYMAP ) {
+               if ( mapping->from == character )
+                       return mapping->to;
+       }
+       return character;
+}
+
 /**
  * Get character from BIOS console
  *
@@ -251,9 +268,9 @@ static int bios_getchar ( void ) {
                               : "=a" ( keypress ) : "a" ( 0x1000 ) );
        character = ( keypress & 0xff );
 
-       /* If it's a normal character, just return it */
+       /* If it's a normal character, just map and return it */
        if ( character && ( character < 0x80 ) )
-               return character;
+               return bios_keymap ( character );
 
        /* Otherwise, check for a special key that we know about */
        if ( ( ansi_seq = scancode_to_ansi_seq ( keypress >> 8 ) ) ) {

diff --git a/src/include/ipxe/keymap.h b/src/include/ipxe/keymap.h
new file mode 100644 (file)
index 0000000..9ac42a6
--- /dev/null
+++ b/src/include/ipxe/keymap.h
@@ -0,0 +1,30 @@
+#ifndef _IPXE_KEYMAP_H
+#define _IPXE_KEYMAP_H
+
+/**
+ * @file
+ *
+ * Keyboard mappings
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <ipxe/tables.h>
+
+/** A keyboard mapping */
+struct key_mapping {
+       /** Character read from keyboard */
+       uint8_t from;
+       /** Character to be used instead */
+       uint8_t to;
+} __attribute__ (( packed ));
+
+/** Keyboard mapping table */
+#define KEYMAP __table ( struct key_mapping, "keymap" )
+
+/** Define a keyboard mapping */
+#define __keymap __table_entry ( KEYMAP, 01 )
+
+#endif /* _IPXE_KEYMAP_H */