Subversion Repositories core_arm

library ieee;

use ieee.std_logic_1164.all;

-- PREFIX: apm_xxx

package armpmodel is

-------------------------------------------------------------------------------

-- Processor Modes

constant APM_USR : std_logic_vector(4 downto 0) := "10000";        -- 1oooo

constant APM_SYS : std_logic_vector(4 downto 0) := "11111";        -- 11111

constant APM_SVC : std_logic_vector(4 downto 0) := "10011";        -- 1oo11

constant APM_ABT : std_logic_vector(4 downto 0) := "10111";        -- 1o111

constant APM_UND : std_logic_vector(4 downto 0) := "11011";        -- 11o11

constant APM_IRQ : std_logic_vector(4 downto 0) := "10010";        -- 1oo1o

constant APM_FIQ : std_logic_vector(4 downto 0) := "10001";        -- 1ooo1

-- check weather privileged mode

function apm_is_privmode (

  mode : std_logic_vector(4 downto 0)

) return boolean;

-------------------------------------------------------------------------------

-- Trap types

type apm_trap is (

  apm_trap_reset,   -- reset

  apm_trap_undef,   -- undefined (EXSTG)

  apm_trap_swi,     -- software interrupt (DRSTG)

  apm_trap_prefch,  -- prefetch error (IMSTG)

  apm_trap_dabort,  -- data abort error (MESTG)

  apm_trap_irq,     -- interrupt

  apm_trap_fiq      -- fast interrupt

);

-- Trap jump vectors

constant APM_RESET_VEC  : std_logic_vector(31 downto 0) := "00000000000000000000000000000000";

constant APM_UNDEF_VEC  : std_logic_vector(31 downto 0) := "00000000000000000000000000000100";

constant APM_SWI_VEC    : std_logic_vector(31 downto 0) := "00000000000000000000000000001000";

constant APM_PREFCH_VEC : std_logic_vector(31 downto 0) := "00000000000000000000000000001100";

constant APM_DABORT_VEC : std_logic_vector(31 downto 0) := "00000000000000000000000000010000";

constant APM_IRQ_VEC    : std_logic_vector(31 downto 0) := "00000000000000000000000000011000";

constant APM_FIQ_VEC    : std_logic_vector(31 downto 0) := "00000000000000000000000000011100";

-- Trap ctrl

type apm_trapctrl is record

  traptype : apm_trap;

  trap     : std_logic;

end record;

-------------------------------------------------------------------------------

-- Current Program Status Register (CPSR)

-- +---+---+---+---+---+------------+---+---+---+------+

-- | n | z | c | v | q |   dnm(raz) | i | f | t | mode |

-- +---+---+---+---+---+------------+---+---+---+------+

-- exstg controlled part of CPSR

type apm_excpsr is record

   n      : std_logic;                  -- negative

   z      : std_logic;                  -- zero

   c      : std_logic;                  -- carry

   v      : std_logic;                  -- overflow

   -- extensions

   -- fext   : std_logic_vector(3 downto 0);  -- cpsr(27:24)

   -- xext   : std_logic_vector(7 downto 0);  -- cpsr(15:8)

   -- sext   : std_logic_vector(7 downto 0);  -- cpsr(23:16)

end record;

-- wrstg controlled part of CPSR

type apm_wrcpsr is record

   i      : std_logic;                  -- [7] irq

   f      : std_logic;                  -- [6] fiq

   t      : std_logic;                  -- [5] thumb

   mode   : std_logic_vector(4 downto 0);

-- pragma translate_off

--   dbgmode  : aba_atyp_dbgpmode;       -- readable pmode for dbg

-- pragma translate_on

end record;

-- complete CPSR

type apm_cpsr is record

   ex : apm_excpsr;

   wr : apm_wrcpsr;

end record;

-- Banked SPSR

type apm_spsr is record

    svc_spsr : apm_cpsr;

    abt_spsr : apm_cpsr;

    und_spsr : apm_cpsr;

    irq_spsr : apm_cpsr;

    fiq_spsr : apm_cpsr;

end record;

-- convert from stdlogic to spm_cpsr

function apm_stdtocpsr (

  data : std_logic_vector

) return apm_cpsr;

-- convert from spm_cpsr to stdlogic

function apm_cpsrtostd (

  cpsr : apm_cpsr

) return std_logic_vector;

-- assemble new cpsr for msr cmd

function apm_msr (

  insn : std_logic_vector(31 downto 0);

  newcpsr : apm_cpsr;

  oldcpsr : apm_cpsr

) return apm_cpsr;

constant APM_MSR_C : integer := 16;

constant APM_MSR_X : integer := 17;

constant APM_MSR_S : integer := 18;

constant APM_MSR_F : integer := 19;

-------------------------------------------------------------------------------

constant APM_RREAL_U : integer := 4; -- banked register range

constant APM_RREAL_D : integer := 0;

constant APM_REG_U : integer := 3;   -- logical register range

constant APM_REG_D : integer := 0;

constant APM_REG_LINK   : std_logic_vector(3 downto 0) := "1110";   -- link register

constant APM_REG_PC     : std_logic_vector(3 downto 0) := "1111";   -- programm counter

constant APM_RREAL_PC : std_logic_vector(4 downto 0) := "01111";  -- banked program counter

constant APM_REGLIST_SZ : integer := 16;

constant APM_REGLIST_pc : integer := 15;

-------------------------------------------------------------------------------

-- map to banked register of <mode>

function apm_bankreg(

  mode : in std_logic_vector(4 downto 0);

  addr : in std_logic_vector

) return std_logic_vector;

-- retrieve the banked spsr for <mode> 

function apm_bankspsr(

  mode : in  std_logic_vector(4 downto 0);

  spsr : in  apm_spsr

) return apm_cpsr;

-- set bank spsr

procedure apm_setspsr(

  mode : in  std_logic_vector(4 downto 0);

  spsr : inout  apm_spsr;

  cpsr : in  apm_cpsr

);

-- check weather <mode> has a spsr

function apm_is_hasspsr (

  mode : std_logic_vector(4 downto 0)

) return boolean;

end armpmodel;

package body armpmodel is

-------------------------------------------------------------------------------

function apm_is_privmode (

  mode : std_logic_vector(4 downto 0)

) return boolean is

  variable tmp : boolean;

begin

  tmp := true;

  if mode = APM_USR then

    tmp := false;

  end if;

  return tmp;

end;

-------------------------------------------------------------------------------

constant APM_N_C : integer := 31;

constant APM_Z_C : integer := 30;

constant APM_C_C : integer := 29;

constant APM_V_C : integer := 28;

constant APM_Q_C : integer := 27;

constant APM_I_C : integer := 7;

constant APM_F_C : integer := 6;

constant APM_T_C : integer := 5;

constant APM_MODE_U : integer := 4;

constant APM_MODE_D : integer := 0;

-- extensions

-- constant APM_FEXT_U : integer := 27;

-- constant APM_FEXT_D : integer := 24;

-- constant APM_XEXT_U : integer := 15;

-- constant APM_XEXT_D : integer := 8;

-- constant APM_SEXT_U : integer := 23;

-- constant APM_SEXT_D : integer := 16;

function apm_stdtocpsr (

  data : std_logic_vector

) return apm_cpsr is

  variable tmp : apm_cpsr;

begin

  tmp.ex.n := data(APM_N_C);

  tmp.ex.z := data(APM_Z_C);

  tmp.ex.c := data(APM_C_C);

  tmp.ex.v := data(APM_V_C);

  tmp.wr.i := data(APM_I_C);

  tmp.wr.f := data(APM_F_C);

  tmp.wr.t := data(APM_T_C);

  tmp.wr.mode := data(APM_MODE_U downto APM_MODE_D);

  -- extensions

  -- tmp.fext := data(ACP_FEXT_U downto ACP_FEXT_D);

  -- tmp.xext := data(ACP_XEXT_U downto ACP_XEXT_D);

  -- tmp.sext := data(ACP_SEXT_U downto ACP_SEXT_D);

  return tmp;

end;

function apm_cpsrtostd (

  cpsr : apm_cpsr

) return std_logic_vector is

  variable tmp : std_logic_vector(31 downto 0);

begin

  tmp := (others => '0');

  tmp(APM_N_C) := cpsr.ex.n;

  tmp(APM_Z_C) := cpsr.ex.z;

  tmp(APM_C_C) := cpsr.ex.c;

  tmp(APM_V_C) := cpsr.ex.v;

  tmp(APM_Q_C) := '0';

  tmp(APM_I_C) := cpsr.wr.i;

  tmp(APM_F_C) := cpsr.wr.f;

  tmp(APM_T_C) := cpsr.wr.t;

  tmp(APM_MODE_U downto APM_MODE_D) := cpsr.wr.mode;

  -- extensions

  -- tmp(ACP_FEXT_U downto ACP_FEXT_D) := cpsr.fext;

  -- tmp(ACP_XEXT_U downto ACP_XEXT_D) := cpsr.xext;

  -- tmp(ACP_SEXT_U downto ACP_SEXT_D) := cpsr.sext;

  return tmp;

end;

function apm_msr (

  insn : std_logic_vector(31 downto 0);

  newcpsr : apm_cpsr;

  oldcpsr : apm_cpsr

) return apm_cpsr is

  variable tmp : apm_cpsr;

begin

  tmp := oldcpsr;

  -- +---+---+---+---+---+------------+---+---+---+------+

  -- | n | z | c | v | q |   dnm(raz) | i | f | t | mode |

  -- +---+---+---+---+---+------------+---+---+---+------+

  -- $(del)

  -- if opcode[25] == 1

  --   operand = 8_bit_immediate Rotate_Right (rotate_imm * 2)

  -- else /* opcode[25] == 0 */

  --   operand = Rm

  --

  -- if R == 0 then

  --   if field_mask[0] == 1 and InAPrivilegedMode() then

  --   CPSR[7:0] = operand[7:0]

  --   if field_mask[1] == 1 and InAPrivilegedMode() then

  --   CPSR[15:8] = operand[15:8]

  --   if field_mask[2] == 1 and InAPrivilegedMode() then

  --   CPSR[23:16] = operand[23:16]

  --   if field_mask[3] == 1 then

  --   CPSR[31:24] = operand[31:24]

  -- else /* R == 1 */

  --   if field_mask[0] == 1 and CurrentModeHasSPSR() then

  --   SPSR[7:0] = operand[7:0]

  --   if field_mask[1] == 1 and CurrentModeHasSPSR() then

  --   SPSR[15:8] = operand[15:8]

  --   if field_mask[2] == 1 and CurrentModeHasSPSR() then

  --   SPSR[23:16] = operand[23:16]

  --   if field_mask[3] == 1 and CurrentModeHasSPSR() then

  --   SPSR[31:24] = operand[31:24]

  -- $(/del)

  if insn(APM_MSR_C) = '1' then

    tmp.wr.i := newcpsr.wr.i;

    tmp.wr.f := newcpsr.wr.f;

    tmp.wr.t := newcpsr.wr.t;

    tmp.wr.mode := newcpsr.wr.mode;

  end if;

  if insn(APM_MSR_X) = '1' then

    -- extensions

    -- tmp.xext := newcpsr.xext;

  end if;

  if insn(APM_MSR_S) = '1' then

    -- extensions

    -- tmp.sext := newcpsr.sext;

  end if;

  if insn(APM_MSR_F) = '1' then

    tmp.ex.n := newcpsr.ex.n;

    tmp.ex.z := newcpsr.ex.z;

    tmp.ex.c := newcpsr.ex.c;

    tmp.ex.v := newcpsr.ex.v;

    -- extensions

    -- tmp.ex.fext := newcpsr.fext;

  end if;

  return tmp;

end;

-------------------------------------------------------------------------------

-- banked register mapping:

-- 

--          USR     SYS     SVC     ABT     UND     IRQ     FIQ  

--       +-------+-------+-------+-------+-------+-------+-------+

--R0-R7  |      

--       +-------+---------------------------------------+-------+

--R8-R12 |                                                R16-R20

--       +-------+---------------------------------------+-------+

--R13    |                   R24    R26     R28    R30      R21 

--       +-------+---------------------------------------+-------+

--R14    |                   R25    R27     R29    R31      R22

--       +-------+---------------------------------------+-------+

function apm_bankreg(

  mode : in std_logic_vector(4 downto 0);

  addr : in std_logic_vector

) return std_logic_vector is

variable tmp  : std_logic_vector(addr'high+1 downto 0);  -- +1: return is 5bits

variable bank : std_logic_vector(addr'high+1 downto 0);

begin

  tmp := "0"&addr(addr'high downto 0);

  bank := "0"&addr(addr'high downto 0);

  case mode is

    when APM_USR =>

    when APM_SYS =>

    when APM_SVC =>

      bank := "1100" & not addr(0);

    when APM_ABT =>

      bank := "1101" & not addr(0);

    when APM_UND =>

      bank := "1110" & not addr(0);

    when APM_FIQ =>

      if addr(3) = '1' then

        bank(4 downto 3) := "10";

        tmp(4 downto 3) := "10";

      end if;

    when APM_IRQ =>

      bank := "1111" & not addr(0);

    when others =>

  end case;

  case addr(3 downto 0) is

    when "1101"|"1110" => tmp := bank;

    when others =>

  end case;

  return tmp;

end;

procedure apm_setspsr(

  mode : in  std_logic_vector(4 downto 0);

  spsr : inout  apm_spsr;

  cpsr : in  apm_cpsr

) is

begin

  case mode is

    when APM_SVC =>

      spsr.svc_SPSR := cpsr;

    when APM_ABT =>

      spsr.abt_SPSR := cpsr;

    when APM_UND =>

      spsr.und_SPSR := cpsr;

    when APM_IRQ =>

      spsr.irq_SPSR := cpsr;

    when APM_FIQ =>

      spsr.fiq_SPSR := cpsr;

    when others =>

  end case;

end;

function apm_bankspsr(

  mode : in  std_logic_vector(4 downto 0);

  spsr : in  apm_spsr

) return apm_cpsr is

variable tmp : apm_cpsr;

begin

  tmp := spsr.svc_spsr;

  case mode is

    when APM_SVC =>

      tmp := spsr.svc_spsr;

    when APM_ABT =>

      tmp := spsr.abt_spsr;

    when APM_UND =>

      tmp := spsr.und_spsr;

    when APM_IRQ =>

      tmp := spsr.irq_spsr;

    when APM_FIQ =>

      tmp := spsr.fiq_spsr;

    when others =>

  end case;

  return tmp;

end;

function apm_is_hasspsr (

  mode : std_logic_vector(4 downto 0)

) return boolean is

  variable tmp : boolean;

begin

  tmp := true;

  if mode = APM_USR or

     mode = APM_SYS then

    tmp := false;

  end if;

  return tmp;

end;

end armpmodel;