ps_seg.asm

操作系统实验教程核心技术与编程实例书中地例子代码

USER_PsTSSSEG  SEGMENT PARA USE16
USER_Ps_TASK    TASKSS <>
            DB 0FFH
USER_PsTSSLEN  = $
USER_PsTSSSEG  ENDS

USER_PsLDTSEG SEGMENT
USER_PsLDT    LABEL BYTE
USER_PsLDT_NULL      GDT_DESC <>  
USER_Ps       GDT_DESC  10 dup (<>) ;EXE DPL=0
USER_Ps_SEL    = USER_Ps - USER_PsLDT + 04H
USER_Ps_LDT_INIT_BEGIN LABEL BYTE
USER_PsLDT_ASDATA  GDT_DESC <USER_PsLDTLEN,USER_PsLDTSEG,0,92H,0,0>
USER_PsLDT_ASDATA_SEL = USER_PsLDT_ASDATA - USER_PsLDT + 04H
USER_Ps_LDT_INIT_COUNT  = ($ - USER_Ps_LDT_INIT_BEGIN)/(SIZE GDT_DESC)
Ps_TO_TOS      GAT_DESC <0,TOS_TSS_SEL,0,85H,0>  ;85h:task gate
Ps_TO_TOS_SEL  = (Ps_TO_TOS - USER_PsLDT) + 04H
USER_PsLDTLEN  = $ - USER_PsLDT
USER_PsLDTSEG ENDS