⟦6da1d5368⟧

E3 Source Code



-- Copyright 1991 Verdix Corporation

with System;
use System;
with Unchecked_Conversion;
package Krn_Cpu_Defs is
    pragma Suppress (All_Checks);
    pragma Suppress (Exception_Tables);
    pragma Not_Elaborated;

    -------------------------------------------------------------------------
    -- Kernel type definitions that are M68K cross target specific
    -------------------------------------------------------------------------

    -- Allocation and stack alignment
    Alignment : constant := 4;

    -- Size of exception stack frame for a trap instruction
    Trap_Frame_Size : constant := 8;

    -- This is to get around the problem with 'SIZE not working when
    -- the elaboration code doesn't get executed.
    Storage_Units_Per_Word : constant := 4;


    -- Note: for RTS performance reasons a6, a7 and pc aren't being
    -- updated. They're only there for the debugger.
    type Cpu_State_T is
        record
            A6 : Address; -- fp\x09\x09-- 0
            A7 : Address; -- sp\x09\x09-- 4
            Pc : Address;    -- 8
            Sr : Short_Integer;   -- c
            Sr_Pad : Short_Integer;

            -- When entered_from_intr = TRUE, restore_ssp points to
            -- preempted_state_t record pushed on the task's supervisor stack.
            -- The task's SSP is equal to the restore_ssp after this
            -- record has been popped from the stack. The restore_usp field
            -- contains the task's USP. None of the above registers
            -- are valid.
            --
            -- When entered_from_intr = 0, the above registers reflect
            -- the task's state upon entering the RTS.
            Entered_From_Intr : Boolean;  -- 10
            Entered_From_Intr_Pad1 : Tiny_Integer; -- 11
            Entered_From_Intr_Pad2 : Short_Integer; -- 12
            Restore_Ssp : Address;  -- 14
            Restore_Usp : Address;  -- 18
            Stack_Limit : Address;  -- 1c
        end record;
    for Cpu_State_T'Size use 16#20# * 8;
    type A_Cpu_State_T is access Cpu_State_T;

    -- Length of fields in krn_tcb_t record preceding cpu_state.
    Cpu_State_Offset : constant := 0;
    -- CPU state record field offsets from beginning of task control
    -- block, not beginning of cpu_state
    A6_Offset : constant := Cpu_State_Offset + 16#00#;
    A7_Offset : constant := Cpu_State_Offset + 16#04#;
    Pc_Offset : constant := Cpu_State_Offset + 16#08#;
    Sr_Offset : constant := Cpu_State_Offset + 16#0C#;

    Fp_Offset : constant := A6_Offset;
    Sp_Offset : constant := A7_Offset;

    Entered_From_Intr_Offset : constant := Cpu_State_Offset + 16#10#;
    Restore_Ssp_Offset : constant := Cpu_State_Offset + 16#14#;
    Restore_Usp_Offset : constant := Cpu_State_Offset + 16#18#;
    Stack_Limit_Offset : constant := Cpu_State_Offset + 16#1C#;


    --
    -- The following state is pushed on the current task's supervisor stack
    -- when the RTS is entered from an interrupt. For this case,
    -- ts.ct.proc_state.entered_from_intr = TRUE and
    -- ts.ct.proc_state.restore_ssp points to this record on the stack.
    --
    type Preempted_Reg_T is array (0 .. 14) of Integer; -- d0..d7, a0..a6
    type Preempted_State_T is
        record
            Preempted_Reg : Preempted_Reg_T;
            Sr : Short_Integer;
            Pc : Integer;
        end record;
    pragma Pack (Preempted_State_T);
    for Preempted_State_T'Size use 8 * 32 + 7 * 32 + 16 + 32;
    type A_Preempted_State_T is access Preempted_State_T;

    --
    -- The following state is pushed on the current task's supervisor stack
    -- before doing a task switch. For this case,
    -- ts.ct.proc_state.entered_from_intr = FALSE and
    -- ts.ct.proc_state.restore_ssp points to this record on the stack.
    --
    type Switch_Reg_T is array (0 .. 8) of Integer; -- d4..d7, a2..a6
    type Task_Switch_State_T is
        record
            Switch_Reg : Switch_Reg_T;
            Pc : Integer;
        end record;
    pragma Pack (Task_Switch_State_T);
    for Task_Switch_State_T'Size use 4 * 32 + 5 * 32 + 32;
    type A_Task_Switch_State_T is access Task_Switch_State_T;

end Krn_Cpu_Defs;
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⟦6da1d5368⟧ Ada Source

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