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| author | jhb <jhb@FreeBSD.org> | 2012-03-06 20:45:13 +0000 |
|---|---|---|
| committer | jhb <jhb@FreeBSD.org> | 2012-03-06 20:45:13 +0000 |
| commit | 13aacec1f8c622aee729b991194b07b3ab64b7e9 (patch) | |
| tree | 2bc15f9fd8c67bda5eb07cd7d1e8c2716378f5c6 /sys/boot/i386 | |
| parent | 62cc1e85ffa80f350cf6b12ed71008c196e47c54 (diff) | |
| download | FreeBSD-src-13aacec1f8c622aee729b991194b07b3ab64b7e9.zip FreeBSD-src-13aacec1f8c622aee729b991194b07b3ab64b7e9.tar.gz | |
Add a note to clarify why we create a relocated copy of boot1 in lower
memory.
Diffstat (limited to 'sys/boot/i386')
| -rw-r--r-- | sys/boot/i386/boot2/boot1.S | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/sys/boot/i386/boot2/boot1.S b/sys/boot/i386/boot2/boot1.S index 14d28b3..984ab52 100644 --- a/sys/boot/i386/boot2/boot1.S +++ b/sys/boot/i386/boot2/boot1.S @@ -125,7 +125,10 @@ main: cld # String ops inc mov $start,%sp # stack /* * Relocate ourself to MEM_REL. Since %cx == 0, the inc %ch sets - * %cx == 0x100. + * %cx == 0x100. Note that boot1 does not use this relocated copy + * of itself while loading boot2; however, BTX reclaims the memory + * used by boot1 during its initialization. As a result, boot2 uses + * xread from the relocated copy. */ mov %sp,%si # Source mov $MEM_REL,%di # Destination |
