add some comments

find out the hard way why user and kernel must have separate segment descriptors

1 files changed, 2 insertions, 0 deletions

diff --git a/asm.h b/asm.h
index 0c052db..68210d7 100644
--- a/asm.h
+++ b/asm.h
@@ -6,6 +6,8 @@
         .word 0, 0;                                             \
         .byte 0, 0, 0, 0
 
+// The 0xC0 means the limit is in 4096-byte units
+// and (for executable segments) 32-bit mode.
 #define SEG_ASM(type,base,lim)                                  \
         .word (((lim) >> 12) & 0xffff), ((base) & 0xffff);      \
         .byte (((base) >> 16) & 0xff), (0x90 | (type)),         \