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| author | Joel Sherrill <joel.sherrill@OARcorp.com> | 2002-08-14 22:43:10 +0000 |
|---|---|---|
| committer | Joel Sherrill <joel.sherrill@OARcorp.com> | 2002-08-14 22:43:10 +0000 |
| commit | 37bb9bfd027f9ceb5d6293cd4cfa3dce2ac95482 (patch) | |
| tree | 944d3306d497a572717c161a29f918cefc61d273 /c/src/lib/libbsp/i386/pc386/start/start16.S | |
| parent | 2002-08-14 Ralf Corsepius <corsepiu@faw.uni-ulm.de> (diff) | |
| download | rtems-37bb9bfd027f9ceb5d6293cd4cfa3dce2ac95482.tar.bz2 | |
2002-08-14 Joel Sherrill <joel@OARcorp.com>
* start/start16.S: Per PR259, added code to test for video present
before touching the adapter. Eric Norum <eric.norum@usask.ca>
tested this patch.
Diffstat (limited to 'c/src/lib/libbsp/i386/pc386/start/start16.S')
| -rw-r--r-- | c/src/lib/libbsp/i386/pc386/start/start16.S | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/i386/pc386/start/start16.S b/c/src/lib/libbsp/i386/pc386/start/start16.S index a06199ade7..9434c27723 100644 --- a/c/src/lib/libbsp/i386/pc386/start/start16.S +++ b/c/src/lib/libbsp/i386/pc386/start/start16.S @@ -54,6 +54,11 @@ _start16: #if defined(RTEMS_VIDEO_80x50) + movl $0x0040,%eax # use 32 bit constant to ensure 16 MSB=0 + mov %ax,%es + movw %es:0x4a, %ax # get 16 bit number of columns + cmpw $0, %ax # or 0 if no video adapter + je 1f # if no video, skip touching it /*---------------------------------------------------------------------+ | Switch VGA video to 80 lines x 50 columns mode. Has to be done before | turning protected mode on since it uses BIOS int 10h (video) services. @@ -71,6 +76,7 @@ _start16: movw $0x0007, %cx int $0x10 ++1: #endif /* RTEMS_VIDEO_80x50 */ /*---------------------------------------------------------------------+ |