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| author | H. Peter Anvin <hpa@zytor.com> | 2010-01-21 21:36:52 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2010-01-21 21:38:50 -0800 |
| commit | 8f189531a58aef0655cd04a620931da3a0157eaa (patch) | |
| tree | ff0e2832725fb9dc0afe19d474942138151cf9e4 | |
| parent | 10bc1d024e41c545ddd2a820e6da656e4f4b0f4b (diff) | |
| download | syslinux-8f189531a58aef0655cd04a620931da3a0157eaa.tar.gz syslinux-8f189531a58aef0655cd04a620931da3a0157eaa.tar.xz syslinux-8f189531a58aef0655cd04a620931da3a0157eaa.zip | |
core/diskio: correct the EDD parameter query
We need to tell the BIOS how big of a buffer we have for the EDD
parameter query. This caused us to *never* use EDD, which meant that
large filesystems never worked.
Reported-by: Gert Hulselmans <kimmik999999@yahoo.co.uk>
Isolated-by: Alek Du <alek.du@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| -rw-r--r-- | core/diskio.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/core/diskio.c b/core/diskio.c index 911e4ddf..eddcd8d8 100644 --- a/core/diskio.c +++ b/core/diskio.c @@ -254,14 +254,20 @@ struct disk *disk_init(uint8_t devno, bool cdrom, sector_t part_start, if (cdrom || (!(oreg.eflags.l & EFLAGS_CF) && oreg.ebx.w[0] == 0xaa55 && (oreg.ecx.b[0] & 1))) { + ebios = true; + /* Query EBIOS parameters */ + edd_params.len = sizeof edd_params; + ireg.eax.b[1] = 0x48; ireg.ds = SEG(&edd_params); ireg.esi.w[0] = OFFS(&edd_params); __intcall(0x13, &ireg, &oreg); if (!(oreg.eflags.l & EFLAGS_CF) && oreg.eax.b[1] == 0) { - ebios = true; + if (edd_params.len < sizeof edd_params) + memset((char *)&edd_params + edd_params.len, 0, + sizeof edd_params - edd_params.len); if (edd_params.sector_size >= 512 && is_power_of_2(edd_params.sector_size)) sector_size = edd_params.sector_size; |