Add console functionality

Keys I keep hitting should work like I expect them to.

Home or Ctrl+A = move to beginning of line
End or Ctrl+E = move to end of line
Del = delete-right
Ctrl+K = delete to end of line
Ctrl+L = clear screen and reprint current line
Ctrl+N = next command
Ctrl+P = previous command

Also, improve filtering of escape sequences and non-printable
characters, so hitting unsupported keys or control codes doesn't mess
up the current line of input.

BUG=chrome-os-partner:11666
TEST=manual

  type 'fhelpbar'
  home -> cursor moves to beginning of line
  Ctrl+E -> cursor moves to end of line
  Ctrl+A -> cursor moves to beginning of line
    (of course, if you're using Minicom, you'll need to type Ctrl+A A, since
     Minicom uses Ctrl+A as its control key)
  del -> 'helpbar'
  end -> cursor moves to end of line
  left-arrow 3 times -> cursor moves under 'b'
  Ctrl+L -> screen clears, cursor still under 'b'
  Ctrl+K -> 'help'
  Ctrl+Y Page-Up Page-Down -> nothing printed
  enter -> prints known commands (output of 'help' command)
  Ctrl+P -> 'help'
  Ctrl+N -> empty command line

Change-Id: Id893c93b26db8f3deed6ea8be5aab88a3daaead4
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/28143

1 files changed, 1 insertions, 0 deletions

diff --git a/include/util.h b/include/util.h
index 423408a45c..2c6affddde 100644
--- a/include/util.h
+++ b/include/util.h
@@ -66,6 +66,7 @@ int atoi(const char *nptr);
 int isdigit(int c);
 int isspace(int c);
 int isalpha(int c);
+int isprint(int c);
 void *memcpy(void *dest, const void *src, int len);
 void *memset(void *dest, int c, int len);
 void *memmove(void *dest, const void *src, int len);