DOS/32 Advanced DOS Extender - Programmer's Reference 2.07 - DPMI function 0008h - Set Segment Limit Sets the limit field in the descriptor table for the specified segment.
In: | AX = 0008h BX = selector CX:DX = 32-bit segment limit
Out: | if successful: CF clear if failed: CF set AX = error code 8021h - invalid value (the limit is greater than 1 MB but the low 12 bits are not set) 8022h - invalid selector 8025h - invalid linear address (changing the limit would cause the descriptor to reference a linear address range outside that allowed for DPMI clients.)
Notes: a) The value supplied to the function in CX:DX is the byte length of the segment-1 (ie, the value returned by the LSL instruction). b) Segment limits greater than or equal to 1 MB must be page-aligned. That is, limits greater than 1 MB must have the low 12 bits set. c) This function has an implicit effect on the "G" (granularity) bit in an 80386+ descriptor's extended access rights/type byte; ie, it is the host's responsibility to set the "G" bit correctly. d) Client programs must use the LSL instruction to query the limit for a descriptor. Note that on 80386 machines, the client must use the 32-bit form of LSL if the segment size is greater than 64 KB. e) DOS/32 Advanced DPMI and DPMI 1.0 hosts will reload any segment registers which contain the selector specified in register BX. Copyright © Supernar Systems, Ltd. 1996-2002 All Rights Reserved.