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author | cognet <cognet@FreeBSD.org> | 2009-01-22 15:36:11 +0000 |
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committer | cognet <cognet@FreeBSD.org> | 2009-01-22 15:36:11 +0000 |
commit | 3959d9afa29c69635f686030e4b0f2a7571c184c (patch) | |
tree | 7548f1eaff1101d987699d09aa5354a8375a07c5 /sys/arm | |
parent | 6b4a126c250d970139633934fa8a0cdbaebb195c (diff) | |
download | FreeBSD-src-3959d9afa29c69635f686030e4b0f2a7571c184c.zip FreeBSD-src-3959d9afa29c69635f686030e4b0f2a7571c184c.tar.gz |
Add a comment explaining what ARM_KERN_DIRECTMAP is all about.
Suggested by: raj
Diffstat (limited to 'sys/arm')
-rw-r--r-- | sys/arm/include/vmparam.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/sys/arm/include/vmparam.h b/sys/arm/include/vmparam.h index a3d8425..bc82fd0 100644 --- a/sys/arm/include/vmparam.h +++ b/sys/arm/include/vmparam.h @@ -97,6 +97,13 @@ #define VM_MIN_ADDRESS (0x00001000) #ifdef ARM_USE_SMALL_ALLOC +/* + * ARM_KERN_DIRECTMAP is used to make sure there's enough space between + * VM_MAXUSER_ADDRESS and KERNBASE to map the whole memory. + * It has to be a compile-time constant, even if arm_init_smallalloc(), + * which will do the mapping, gets the real amount of memory at runtime, + * because VM_MAXUSER_ADDRESS is a constant. + */ #ifndef ARM_KERN_DIRECTMAP #define ARM_KERN_DIRECTMAP 512 * 1024 * 1024 /* 512 MB */ #endif |