diff options
author | Joel Sherrill <joel.sherrill@OARcorp.com> | 1999-12-03 15:46:17 +0000 |
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committer | Joel Sherrill <joel.sherrill@OARcorp.com> | 1999-12-03 15:46:17 +0000 |
commit | 76c356f36509a72638ee794fc271e562bf991960 (patch) | |
tree | 56f7e4ee47727f4d944aac3bc136c09b0cd2a098 /c/src/lib/libbsp/i386/pc386/startup | |
parent | Modem example driver for ppp by Tomasz Domin <dot@comarch.pl> of ComArch SA. (diff) | |
download | rtems-76c356f36509a72638ee794fc271e562bf991960.tar.bz2 |
Patch from Aleksey (Quality Quorum <qqi@world.std.com>) to change the
delay loop in this BSP. Here is his response to a question about
the patch:
Yes, or that other machine has a different chipset with different
timing requirements on enabling Gate 20. I am strongly suspecting
that it may some how related to the video card I am using (on my
old P-75 target it was plain PCI VGA, on my new one it is Diamond Stealth
3D 2000).
Diffstat (limited to 'c/src/lib/libbsp/i386/pc386/startup')
-rw-r--r-- | c/src/lib/libbsp/i386/pc386/startup/ldsegs.S | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/c/src/lib/libbsp/i386/pc386/startup/ldsegs.S b/c/src/lib/libbsp/i386/pc386/startup/ldsegs.S index 8e082909d7..63f5052f80 100644 --- a/c/src/lib/libbsp/i386/pc386/startup/ldsegs.S +++ b/c/src/lib/libbsp/i386/pc386/startup/ldsegs.S @@ -52,16 +52,35 @@ BEGIN_CODE EXTERN (Timer_exit) EXTERN (clockOff) - .p2align 4 /*----------------------------------------------------------------------------+ | delay +------------------------------------------------------------------------------ -| Delay is needed after doing I/O. We do it by writing to a non-existent port. +| Delay is needed after doing I/O. +| +| The outb version is OK on most machines BUT the loop version ... +| +| will delay for 1us on 1Gz machine, it will take a little bit +| longer on slower machines, however, it does not matter because we +| are going to call this function only a few times + +----------------------------------------------------------------------------*/ -SYM(delay): - outb al, $0x80 # about 1uS delay + .p2align 4 + .globl _delay + .globl delay +delay: +_delay: +/* + outb %al, $0xED # about 1uS delay on most machines +*/ +/* + + movl $0x200, %eax +delay1: + dec %eax + jnz delay1 ret + /*-------------------------------------------------------------------------+ | Function: _load_segments | Description: Current environment is standard PC booted by grub. |