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    • Top-level-memory

    Rme64

    Read an unsigned 64-bit value from memory via an effective address.

    Signature
    (rme64 proc-mode eff-addr seg-reg r-x check-alignment? x86) 
      → 
    (mv flg value x86-new)
    Arguments
    check-alignment? — Guard (booleanp check-alignment?).
    Returns
    value — Type (unsigned-byte-p 64 value), given (x86p x86).
    x86-new — Type (x86p x86-new), given (x86p x86).

    The effective address eff-addr is translated to a canonical linear address using ea-to-la. If this translation is successful and no other errors (like alignment errors) occur, then rml64 is called.

    Prior to the effective address translation, we check whether read access is allowed. The only case in which it is not allowed is when a read access is attempted on an execute-only code segment, in 32-bit mode. In 64-bit mode, the R bit of the code segment descriptor is ignored (see Atmel manual, Dec'17, Volume 2, Section 4.8.1).

    Definitions and Theorems

    Function: rme64$inline

    (defun rme64$inline (proc-mode eff-addr
                                   seg-reg r-x check-alignment? x86)
     (declare (xargs :stobjs (x86)))
     (declare (type (integer 0 4) proc-mode)
              (type (signed-byte 64) eff-addr)
              (type (integer 0 5) seg-reg)
              (type (member :r :x) r-x))
     (declare (xargs :guard (booleanp check-alignment?)))
     (b*
      (((when
         (and (/= proc-mode 0)
              (= seg-reg 1)
              (eq r-x :r)
              (b* ((attr (loghead 16 (seg-hidden-attri seg-reg x86)))
                   (r (code-segment-descriptor-attributesbits->r attr)))
                (= r 0))))
        (mv (list :execute-only-code-segment eff-addr)
            0 x86))
       ((mv flg lin-addr)
        (ea-to-la proc-mode eff-addr seg-reg 8 x86))
       ((when flg) (mv flg 0 x86))
       ((unless (or (not check-alignment?)
                    (address-aligned-p lin-addr 8 nil)))
        (mv (list :unaligned-linear-address lin-addr)
            0 x86)))
      (rml64 lin-addr r-x x86)))

    Theorem: return-type-of-rme64.value

    (defthm return-type-of-rme64.value
      (implies (x86p x86)
               (b* (((mv ?flg acl2::?value ?x86-new)
                     (rme64$inline proc-mode eff-addr
                                   seg-reg r-x check-alignment? x86)))
                 (unsigned-byte-p 64 value)))
      :rule-classes :rewrite)

    Theorem: x86p-of-rme64.x86-new

    (defthm x86p-of-rme64.x86-new
      (implies (x86p x86)
               (b* (((mv ?flg acl2::?value ?x86-new)
                     (rme64$inline proc-mode eff-addr
                                   seg-reg r-x check-alignment? x86)))
                 (x86p x86-new)))
      :rule-classes :rewrite)

    Theorem: n64p-of-mv-nth-1-rme64

    (defthm n64p-of-mv-nth-1-rme64
     (unsigned-byte-p 64
                      (mv-nth 1
                              (rme64 proc-mode eff-addr
                                     seg-reg r-x check-alignment? x86)))
     :rule-classes
     (:rewrite
      (:type-prescription
          :corollary
          (natp (mv-nth 1
                        (rme64 proc-mode eff-addr
                               seg-reg r-x check-alignment? x86)))
          :hints
          (("Goal" :in-theory '(unsigned-byte-p integer-range-p natp))))
      (:linear
       :corollary
       (and (<= 0
                (mv-nth 1
                        (rme64 proc-mode eff-addr
                               seg-reg r-x check-alignment? x86)))
            (< (mv-nth 1
                       (rme64 proc-mode eff-addr
                              seg-reg r-x check-alignment? x86))
               18446744073709551616))
       :hints
       (("Goal"
            :in-theory '(unsigned-byte-p integer-range-p (:e expt)))))))

    Theorem: rme64-value-when-error

    (defthm rme64-value-when-error
      (implies (mv-nth 0
                       (rme64 proc-mode eff-addr
                              seg-reg r-x check-alignment? x86))
               (equal (mv-nth 1
                              (rme64 proc-mode eff-addr
                                     seg-reg r-x check-alignment? x86))
                      0)))

    Theorem: rme64-does-not-affect-state-in-app-view

    (defthm rme64-does-not-affect-state-in-app-view
      (implies (app-view x86)
               (equal (mv-nth 2
                              (rme64 proc-mode eff-addr
                                     seg-reg r-x check-alignment? x86))
                      x86)))

    Theorem: xr-rme64-state-app-view

    (defthm xr-rme64-state-app-view
      (implies
           (app-view x86)
           (equal (xr fld index
                      (mv-nth 2
                              (rme64 proc-mode eff-addr
                                     seg-reg r-x check-alignment? x86)))
                  (xr fld index x86))))

    Theorem: xr-rme64-state-sys-view

    (defthm xr-rme64-state-sys-view
      (implies
           (and (not (equal fld :mem))
                (not (equal fld :fault))
                (not (equal fld :tlb)))
           (equal (xr fld index
                      (mv-nth 2
                              (rme64 proc-mode eff-addr
                                     seg-reg r-x check-alignment? x86)))
                  (xr fld index x86))))

    Theorem: rme64-xw-app-view

    (defthm rme64-xw-app-view
     (implies
       (and (app-view x86)
            (not (equal fld :mem))
            (not (equal fld :app-view))
            (not (equal fld :seg-hidden-base))
            (not (equal fld :seg-hidden-limit))
            (not (equal fld :seg-hidden-attr))
            (not (equal fld :seg-visible))
            (not (equal fld :msr)))
       (and (equal (mv-nth 0
                           (rme64 proc-mode
                                  eff-addr seg-reg r-x check-alignment?
                                  (xw fld index value x86)))
                   (mv-nth 0
                           (rme64 proc-mode eff-addr
                                  seg-reg r-x check-alignment? x86)))
            (equal (mv-nth 1
                           (rme64 proc-mode
                                  eff-addr seg-reg r-x check-alignment?
                                  (xw fld index value x86)))
                   (mv-nth 1
                           (rme64 proc-mode eff-addr
                                  seg-reg r-x check-alignment? x86))))))

    Theorem: rme64-xw-sys-view

    (defthm rme64-xw-sys-view
     (implies
      (and (not (app-view x86))
           (not (equal fld :fault))
           (not (equal fld :seg-visible))
           (not (equal fld :seg-hidden-base))
           (not (equal fld :seg-hidden-limit))
           (not (equal fld :seg-hidden-attr))
           (not (equal fld :mem))
           (not (equal fld :ctr))
           (not (equal fld :msr))
           (not (equal fld :rflags))
           (not (equal fld :app-view))
           (not (equal fld :tlb))
           (not (equal fld :marking-view))
           (not (equal fld :implicit-supervisor-access))
           (member-equal fld *x86-field-names-as-keywords*))
      (and
       (equal (mv-nth 0
                      (rme64 proc-mode
                             eff-addr seg-reg r-x check-alignment?
                             (xw fld index value x86)))
              (mv-nth 0
                      (rme64 proc-mode eff-addr
                             seg-reg r-x check-alignment? x86)))
       (equal (mv-nth 1
                      (rme64 proc-mode
                             eff-addr seg-reg r-x check-alignment?
                             (xw fld index value x86)))
              (mv-nth 1
                      (rme64 proc-mode eff-addr
                             seg-reg r-x check-alignment? x86)))
       (equal (mv-nth 2
                      (rme64 proc-mode
                             eff-addr seg-reg r-x check-alignment?
                             (xw fld index value x86)))
              (xw fld index value
                  (mv-nth 2
                          (rme64 proc-mode eff-addr
                                 seg-reg r-x check-alignment? x86)))))))

    Theorem: rme64-xw-sys-view-rflags-not-ac

    (defthm rme64-xw-sys-view-rflags-not-ac
     (implies
      (and (not (app-view x86))
           (equal (rflagsbits->ac value)
                  (rflagsbits->ac (rflags x86))))
      (and
       (equal (mv-nth 0
                      (rme64 proc-mode
                             eff-addr seg-reg r-x check-alignment?
                             (xw :rflags nil value x86)))
              (mv-nth 0
                      (rme64 proc-mode eff-addr
                             seg-reg r-x check-alignment? x86)))
       (equal (mv-nth 1
                      (rme64 proc-mode
                             eff-addr seg-reg r-x check-alignment?
                             (xw :rflags nil value x86)))
              (mv-nth 1
                      (rme64 proc-mode eff-addr
                             seg-reg r-x check-alignment? x86)))
       (equal (mv-nth 2
                      (rme64 proc-mode
                             eff-addr seg-reg r-x check-alignment?
                             (xw :rflags nil value x86)))
              (xw :rflags nil value
                  (mv-nth 2
                          (rme64 proc-mode eff-addr
                                 seg-reg r-x check-alignment? x86)))))))

    Theorem: rme64-when-64-bit-modep-and-not-fs/gs

    (defthm rme64-when-64-bit-modep-and-not-fs/gs
      (implies (and (not (equal seg-reg 4))
                    (not (equal seg-reg 5))
                    (canonical-address-p eff-addr)
                    (or (not check-alignment?)
                        (address-aligned-p eff-addr 8 nil)))
               (equal (rme64 0 eff-addr
                             seg-reg r-x check-alignment? x86)
                      (rml64 eff-addr r-x x86))))

    Theorem: rme64-unaligned-when-64-bit-modep-and-not-fs/gs

    (defthm rme64-unaligned-when-64-bit-modep-and-not-fs/gs
      (implies (and (not (equal seg-reg 4))
                    (not (equal seg-reg 5))
                    (not (or (not check-alignment?)
                             (address-aligned-p eff-addr 8 nil)))
                    (canonical-address-p eff-addr))
               (equal (rme64 0 eff-addr
                             seg-reg r-x check-alignment? x86)
                      (list (list :unaligned-linear-address eff-addr)
                            0 x86))))

    Theorem: rme64-when-64-bit-modep-and-fs/gs

    (defthm rme64-when-64-bit-modep-and-fs/gs
      (implies
           (or (equal seg-reg 4) (equal seg-reg 5))
           (equal (rme64 0 eff-addr
                         seg-reg r-x check-alignment? x86)
                  (b* (((mv flg lin-addr)
                        (b* (((mv base & &)
                              (segment-base-and-bounds 0 seg-reg x86))
                             (lin-addr (i64 (+ base (n64 eff-addr)))))
                          (if (canonical-address-p lin-addr)
                              (mv nil lin-addr)
                            (mv (list :non-canonical-address lin-addr)
                                0))))
                       ((when flg) (mv flg 0 x86))
                       ((unless (or (not check-alignment?)
                                    (address-aligned-p lin-addr 8 nil)))
                        (mv (list :unaligned-linear-address lin-addr)
                            0 x86)))
                    (rml64 lin-addr r-x x86)))))