[bzimage] Fix parsing of "vga=..." when not at end of command line

bzimage_parse_cmdline() uses strcmp() to identify the named "vga=..."
kernel command line option values, which will give a false negative if
the option is not last on the command line.

Fix by temporarily changing the relevant command line separator (if
any) to a NUL terminator.

Debugged-by: Simon Rettberg <simon.rettberg@rz.uni-freiburg.de>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/arch/x86/image/bzimage.c b/src/arch/x86/image/bzimage.c
index a782127a1c40098dc716fb3adc5771ffc2c540cd..769e0c9d8f8f9018307e783135e601f21e8ab362 100644 (file)
--- a/src/arch/x86/image/bzimage.c
+++ b/src/arch/x86/image/bzimage.c
@@ -252,13 +252,17 @@ static void bzimage_update_header ( struct image *image,
  */
 static int bzimage_parse_cmdline ( struct image *image,
                                   struct bzimage_context *bzimg,
-                                  const char *cmdline ) {
+                                  char *cmdline ) {
+       char *sep;
        char *vga;
        char *mem;
 
        /* Look for "vga=" */
        if ( ( vga = strstr ( cmdline, "vga=" ) ) ) {
                vga += 4;
+               sep = strchr ( vga, ' ' );
+               if ( sep )
+                       *sep = '\0';
                if ( strcmp ( vga, "normal" ) == 0 ) {
                        bzimg->vid_mode = BZI_VID_MODE_NORMAL;
                } else if ( strcmp ( vga, "ext" ) == 0 ) {
@@ -267,11 +271,13 @@ static int bzimage_parse_cmdline ( struct image *image,
                        bzimg->vid_mode = BZI_VID_MODE_ASK;
                } else {
                        bzimg->vid_mode = strtoul ( vga, &vga, 0 );
-                       if ( *vga && ( *vga != ' ' ) ) {
-                               DBGC ( image, "bzImage %p strange \"vga=\""
+                       if ( *vga ) {
+                               DBGC ( image, "bzImage %p strange \"vga=\" "
                                       "terminator '%c'\n", image, *vga );
                        }
                }
+               if ( sep )
+                       *sep = ' ';
        }
 
        /* Look for "mem=" */
@@ -522,7 +528,7 @@ static void bzimage_load_initrds ( struct image *image,
  */
 static int bzimage_exec ( struct image *image ) {
        struct bzimage_context bzimg;
-       const char *cmdline = ( image->cmdline ? image->cmdline : "" );
+       char *cmdline = ( image->cmdline ? image->cmdline : "" );
        int rc;
 
        /* Read and parse header from image */