forked from KolibriOS/kolibrios
932 lines
33 KiB
PHP
932 lines
33 KiB
PHP
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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;; ;;
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;; Copyright (C) KolibriOS team 2004-2015. All rights reserved. ;;
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;; Distributed under terms of the GNU General Public License ;;
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;; ;;
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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$Revision$
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; Initializes MTRRs.
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proc init_mtrr
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cmp [BOOT.mtrr], byte 2
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je .exit
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bt [cpu_caps], CAPS_MTRR
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jnc .exit
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call mtrr_reconfigure
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stdcall set_mtrr, [LFBAddress], 0x1000000, MEM_WC
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.exit:
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ret
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endp
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; Helper procedure for mtrr_reconfigure and set_mtrr,
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; called before changes in MTRRs.
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; 1. disable and flush caches
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; 2. clear PGE bit in cr4
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; 3. flush TLB
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; 4. disable mtrr
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proc mtrr_begin_change
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mov eax, cr0
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or eax, 0x60000000 ;disable caching
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mov cr0, eax
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wbinvd ;invalidate cache
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bt [cpu_caps], CAPS_PGE
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jnc .cr3_flush
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mov eax, cr4
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btr eax, 7 ;clear cr4.PGE
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mov cr4, eax ;flush TLB
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jmp @F ;skip extra serialization
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.cr3_flush:
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mov eax, cr3
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mov cr3, eax ;flush TLB
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@@:
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mov ecx, MSR_MTRR_DEF_TYPE
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rdmsr
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btr eax, 11 ;clear enable flag
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wrmsr ;disable mtrr
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ret
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endp
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; Helper procedure for mtrr_reconfigure and set_mtrr,
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; called after changes in MTRRs.
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; 1. enable mtrr
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; 2. flush all caches
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; 3. flush TLB
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; 4. restore cr4.PGE flag, if required
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proc mtrr_end_change
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mov ecx, MSR_MTRR_DEF_TYPE
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rdmsr
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or ah, 8 ; enable variable-ranges MTRR
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and al, 0xF0 ; default memtype = UC
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wrmsr
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wbinvd ;again invalidate
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mov eax, cr0
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and eax, not 0x60000000
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mov cr0, eax ; enable caching
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mov eax, cr3
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mov cr3, eax ;flush tlb
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bt [cpu_caps], CAPS_PGE
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jnc @F
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mov eax, cr4
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bts eax, 7 ;set cr4.PGE flag
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mov cr4, eax
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@@:
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ret
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endp
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; Some limits to number of structures located in the stack.
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MAX_USEFUL_MTRRS = 16
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MAX_RANGES = 16
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; mtrr_reconfigure keeps a list of MEM_WB ranges.
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; This structure describes one item in the list.
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struct mtrr_range
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next dd ? ; next item
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start dq ? ; first byte
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length dq ? ; length in bytes
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ends
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uglobal
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align 4
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num_variable_mtrrs dd 0 ; number of variable-range MTRRs
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endg
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; Helper procedure for MTRR initialization.
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; Takes MTRR configured by BIOS and tries to recongifure them
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; in order to allow non-UC data at top of 4G memory.
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; Example: if low part of physical memory is 3.5G = 0xE0000000 bytes wide,
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; BIOS can configure two MTRRs so that the first MTRR describes [0, 4G) as WB
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; and the second MTRR describes [3.5G, 4G) as UC;
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; WB+UC=UC, so the resulting memory map would be as needed,
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; but in this configuration our attempts to map LFB at (say) 0xE8000000 as WC
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; would be ignored, WB+UC+WC is still UC.
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; So we must keep top of 4G memory not covered by MTRRs,
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; using three WB MTRRs [0,2G) + [2G,3G) + [3G,3.5G),
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; this gives the same memory map, but allows to add further entries.
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; See mtrrtest.asm for detailed input/output from real hardware+BIOS.
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proc mtrr_reconfigure
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push ebp ; we're called from init_LFB, and it feels hurt when ebp is destroyed
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; 1. Prepare local variables.
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; 1a. Create list of MAX_RANGES free (aka not yet allocated) ranges.
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xor eax, eax
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lea ecx, [eax+MAX_RANGES]
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.init_ranges:
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sub esp, sizeof.mtrr_range - 4
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push eax
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mov eax, esp
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dec ecx
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jnz .init_ranges
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mov eax, esp
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; 1b. Fill individual local variables.
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xor edx, edx
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sub esp, MAX_USEFUL_MTRRS * 16 ; .mtrrs
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push edx ; .mtrrs_end
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push edx ; .num_used_mtrrs
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push eax ; .first_free_range
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push edx ; .first_range: no ranges yet
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mov cl, [cpu_phys_addr_width]
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or eax, -1
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shl eax, cl ; note: this uses cl&31 = cl-32, not the entire cl
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push eax ; .phys_reserved_mask
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virtual at esp
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.phys_reserved_mask dd ?
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.first_range dd ?
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.first_free_range dd ?
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.num_used_mtrrs dd ?
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.mtrrs_end dd ?
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.mtrrs rq MAX_USEFUL_MTRRS * 2
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.local_vars_size = $ - esp
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end virtual
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; 2. Get the number of variable-range MTRRs from MTRRCAP register.
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; Abort if zero.
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mov ecx, 0xFE
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rdmsr
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test al, al
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jz .abort
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mov byte [num_variable_mtrrs], al
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; 3. Validate MTRR_DEF_TYPE register.
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mov ecx, 0x2FF
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rdmsr
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; If BIOS has not initialized variable-range MTRRs, fallback to step 7.
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test ah, 8
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jz .fill_ranges_from_memory_map
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; If the default memory type (not covered by MTRRs) is not UC,
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; then probably BIOS did something strange, so it is better to exit immediately
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; hoping for the best.
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cmp al, MEM_UC
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jnz .abort
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; 4. Validate all variable-range MTRRs
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; and copy configured MTRRs to the local array [.mtrrs].
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; 4a. Prepare for the loop over existing variable-range MTRRs.
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mov ecx, 0x200
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lea edi, [.mtrrs]
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.get_used_mtrrs_loop:
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; 4b. For every MTRR, read PHYSBASEn and PHYSMASKn.
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; In PHYSBASEn, clear upper bits and copy to ebp:ebx.
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rdmsr
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or edx, [.phys_reserved_mask]
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xor edx, [.phys_reserved_mask]
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mov ebp, edx
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mov ebx, eax
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inc ecx
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; If PHYSMASKn is not active, ignore this MTRR.
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rdmsr
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inc ecx
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test ah, 8
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jz .get_used_mtrrs_next
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; 4c. For every active MTRR, check that number of local entries is not too large.
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inc [.num_used_mtrrs]
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cmp [.num_used_mtrrs], MAX_USEFUL_MTRRS
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ja .abort
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; 4d. For every active MTRR, store PHYSBASEn with upper bits cleared.
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; This contains the MTRR base and the memory type in low byte.
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mov [edi], ebx
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mov [edi+4], ebp
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; 4e. For every active MTRR, check that the range is continuous:
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; PHYSMASKn with upper bits set must be negated power of two, and
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; low bits of PHYSBASEn must be zeroes:
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; PHYSMASKn = 1...10...0,
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; PHYSBASEn = x...x0...0,
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; this defines a continuous range from x...x0...0 to x...x1...1,
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; length = 10...0 = negated PHYSMASKn.
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; Store length in the local array.
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and eax, not 0xFFF
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or edx, [.phys_reserved_mask]
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mov dword [edi+8], 0
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mov dword [edi+12], 0
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sub [edi+8], eax
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sbb [edi+12], edx
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; (x and -x) is the maximum power of two that divides x.
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; Condition for powers of two: (x and -x) equals x.
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and eax, [edi+8]
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and edx, [edi+12]
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cmp eax, [edi+8]
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jnz .abort
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cmp edx, [edi+12]
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jnz .abort
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sub eax, 1
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sbb edx, 0
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and eax, not 0xFFF
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and eax, ebx
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jnz .abort
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and edx, ebp
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jnz .abort
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; 4f. For every active MTRR, validate memory type: it must be either WB or UC.
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add edi, 16
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cmp bl, MEM_UC
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jz .get_used_mtrrs_next
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cmp bl, MEM_WB
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jnz .abort
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.get_used_mtrrs_next:
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; 4g. Repeat the loop at 4b-4f for all [num_variable_mtrrs] entries.
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mov eax, [num_variable_mtrrs]
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lea eax, [0x200+eax*2]
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cmp ecx, eax
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jb .get_used_mtrrs_loop
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; 4h. If no active MTRRs were detected, fallback to step 7.
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cmp [.num_used_mtrrs], 0
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jz .fill_ranges_from_memory_map
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mov [.mtrrs_end], edi
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; 5. Generate sorted list of ranges marked as WB.
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; 5a. Prepare for the loop over configured MTRRs filled at step 4.
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lea ecx, [.mtrrs]
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.fill_wb_ranges:
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; 5b. Ignore non-WB MTRRs.
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mov ebx, [ecx]
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cmp bl, MEM_WB
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jnz .next_wb_range
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mov ebp, [ecx+4]
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and ebx, not 0xFFF ; clear memory type and reserved bits
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; ebp:ebx = start of the range described by the current MTRR.
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; 5c. Find the first existing range containing a point greater than ebp:ebx.
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lea esi, [.first_range]
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.find_range_wb:
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; If there is no next range or start of the next range is greater than ebp:ebx,
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; exit the loop to 5d.
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mov edi, [esi]
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test edi, edi
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jz .found_place_wb
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mov eax, ebx
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mov edx, ebp
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sub eax, dword [edi+mtrr_range.start]
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sbb edx, dword [edi+mtrr_range.start+4]
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jb .found_place_wb
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; Otherwise, if end of the next range is greater than or equal to ebp:ebx,
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; exit the loop to 5e.
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mov esi, edi
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sub eax, dword [edi+mtrr_range.length]
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sbb edx, dword [edi+mtrr_range.length+4]
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jb .expand_wb
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or eax, edx
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jnz .find_range_wb
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jmp .expand_wb
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.found_place_wb:
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; 5d. ebp:ebx is not within any existing range.
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; Insert a new range between esi and edi.
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; (Later, during 5e, it can be merged with the following ranges.)
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mov eax, [.first_free_range]
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test eax, eax
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jz .abort
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mov [esi], eax
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mov edx, [eax+mtrr_range.next]
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mov [.first_free_range], edx
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mov dword [eax+mtrr_range.start], ebx
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mov dword [eax+mtrr_range.start+4], ebp
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; Don't fill [eax+mtrr_range.next] and [eax+mtrr_range.length] yet,
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; they will be calculated including merges at step 5e.
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mov esi, edi
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mov edi, eax
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.expand_wb:
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; 5e. The range at edi contains ebp:ebx, and esi points to the first range
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; to be checked for merge: esi=edi if ebp:ebx was found in an existing range,
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; esi is next after edi if a new range with ebp:ebx was created.
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; Merge it with following ranges while start of the next range is not greater
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; than the end of the new range.
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add ebx, [ecx+8]
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adc ebp, [ecx+12]
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; ebp:ebx = end of the range described by the current MTRR.
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.expand_wb_loop:
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; If there is no next range or start of the next range is greater than ebp:ebx,
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; exit the loop to 5g.
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test esi, esi
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jz .expand_wb_done
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mov eax, ebx
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mov edx, ebp
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sub eax, dword [esi+mtrr_range.start]
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sbb edx, dword [esi+mtrr_range.start+4]
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jb .expand_wb_done
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; Otherwise, if end of the next range is greater than or equal to ebp:ebx,
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; exit the loop to 5f.
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sub eax, dword [esi+mtrr_range.length]
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sbb edx, dword [esi+mtrr_range.length+4]
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jb .expand_wb_last
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; Otherwise, the current range is completely within the new range.
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; Free it and continue the loop.
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mov edx, [esi+mtrr_range.next]
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cmp esi, edi
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jz @f
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mov eax, [.first_free_range]
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mov [esi+mtrr_range.next], eax
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mov [.first_free_range], esi
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@@:
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mov esi, edx
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jmp .expand_wb_loop
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.expand_wb_last:
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; 5f. Start of the new range is inside range described by esi,
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; end of the new range is inside range described by edi.
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; If esi is equal to edi, the new range is completely within
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; an existing range, so proceed to the next range.
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cmp esi, edi
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jz .next_wb_range
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; Otherwise, set end of interval at esi to end of interval at edi
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; and free range described by edi.
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mov ebx, dword [esi+mtrr_range.start]
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mov ebp, dword [esi+mtrr_range.start+4]
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add ebx, dword [esi+mtrr_range.length]
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adc ebp, dword [esi+mtrr_range.length+4]
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mov edx, [esi+mtrr_range.next]
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mov eax, [.first_free_range]
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mov [esi+mtrr_range.next], eax
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mov [.first_free_range], esi
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mov esi, edx
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.expand_wb_done:
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; 5g. We have found the next range (maybe 0) after merging and
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; the new end of range (maybe ebp:ebx from the new range
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; or end of another existing interval calculated at step 5f).
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; Write them to range at edi.
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mov [edi+mtrr_range.next], esi
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sub ebx, dword [edi+mtrr_range.start]
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sbb ebp, dword [edi+mtrr_range.start+4]
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mov dword [edi+mtrr_range.length], ebx
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mov dword [edi+mtrr_range.length+4], ebp
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.next_wb_range:
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; 5h. Continue the loop 5b-5g over all configured MTRRs.
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add ecx, 16
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cmp ecx, [.mtrrs_end]
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jb .fill_wb_ranges
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; 6. Exclude all ranges marked as UC.
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; 6a. Prepare for the loop over configured MTRRs filled at step 4.
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lea ecx, [.mtrrs]
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.fill_uc_ranges:
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; 6b. Ignore non-UC MTRRs.
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mov ebx, [ecx]
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cmp bl, MEM_UC
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jnz .next_uc_range
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mov ebp, [ecx+4]
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and ebx, not 0xFFF ; clear memory type and reserved bits
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; ebp:ebx = start of the range described by the current MTRR.
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lea esi, [.first_range]
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; 6c. Find the first existing range containing a point greater than ebp:ebx.
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.find_range_uc:
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; If there is no next range, ignore this MTRR,
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; exit the loop and continue to next MTRR.
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mov edi, [esi]
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test edi, edi
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jz .next_uc_range
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; If start of the next range is greater than or equal to ebp:ebx,
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; exit the loop to 6e.
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mov eax, dword [edi+mtrr_range.start]
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mov edx, dword [edi+mtrr_range.start+4]
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sub eax, ebx
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sbb edx, ebp
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jnb .truncate_uc
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; Otherwise, continue the loop if end of the next range is less than ebp:ebx,
|
||
|
; exit the loop to 6d otherwise.
|
||
|
mov esi, edi
|
||
|
add eax, dword [edi+mtrr_range.length]
|
||
|
adc edx, dword [edi+mtrr_range.length+4]
|
||
|
jnb .find_range_uc
|
||
|
; 6d. ebp:ebx is inside (or at end of) an existing range.
|
||
|
; Split the range. (The second range, maybe containing completely within UC-range,
|
||
|
; maybe of zero length, can be removed at step 6e, if needed.)
|
||
|
mov edi, [.first_free_range]
|
||
|
test edi, edi
|
||
|
jz .abort
|
||
|
mov dword [edi+mtrr_range.start], ebx
|
||
|
mov dword [edi+mtrr_range.start+4], ebp
|
||
|
mov dword [edi+mtrr_range.length], eax
|
||
|
mov dword [edi+mtrr_range.length+4], edx
|
||
|
mov eax, [edi+mtrr_range.next]
|
||
|
mov [.first_free_range], eax
|
||
|
mov eax, [esi+mtrr_range.next]
|
||
|
mov [edi+mtrr_range.next], eax
|
||
|
; don't change [esi+mtrr_range.next] yet, it will be filled at step 6e
|
||
|
mov eax, ebx
|
||
|
mov edx, ebp
|
||
|
sub eax, dword [esi+mtrr_range.start]
|
||
|
sbb edx, dword [esi+mtrr_range.start+4]
|
||
|
mov dword [esi+mtrr_range.length], eax
|
||
|
mov dword [esi+mtrr_range.length+4], edx
|
||
|
.truncate_uc:
|
||
|
; 6e. edi is the first range after ebp:ebx, check it and next ranges
|
||
|
; for intersection with the new range, truncate heads.
|
||
|
add ebx, [ecx+8]
|
||
|
adc ebp, [ecx+12]
|
||
|
; ebp:ebx = end of the range described by the current MTRR.
|
||
|
.truncate_uc_loop:
|
||
|
; If start of the next range is greater than ebp:ebx,
|
||
|
; exit the loop to 6g.
|
||
|
mov eax, ebx
|
||
|
mov edx, ebp
|
||
|
sub eax, dword [edi+mtrr_range.start]
|
||
|
sbb edx, dword [edi+mtrr_range.start+4]
|
||
|
jb .truncate_uc_done
|
||
|
; Otherwise, if end of the next range is greater than ebp:ebx,
|
||
|
; exit the loop to 6f.
|
||
|
sub eax, dword [edi+mtrr_range.length]
|
||
|
sbb edx, dword [edi+mtrr_range.length+4]
|
||
|
jb .truncate_uc_last
|
||
|
; Otherwise, the current range is completely within the new range.
|
||
|
; Free it and continue the loop if there is a next range.
|
||
|
; If that was a last range, exit the loop to 6g.
|
||
|
mov edx, [edi+mtrr_range.next]
|
||
|
mov eax, [.first_free_range]
|
||
|
mov [.first_free_range], edi
|
||
|
mov [edi+mtrr_range.next], eax
|
||
|
mov edi, edx
|
||
|
test edi, edi
|
||
|
jnz .truncate_uc_loop
|
||
|
jmp .truncate_uc_done
|
||
|
.truncate_uc_last:
|
||
|
; 6f. The range at edi partially intersects with the UC-range described by MTRR.
|
||
|
; Truncate it from the head.
|
||
|
mov dword [edi+mtrr_range.start], ebx
|
||
|
mov dword [edi+mtrr_range.start+4], ebp
|
||
|
neg eax
|
||
|
adc edx, 0
|
||
|
neg edx
|
||
|
mov dword [edi+mtrr_range.length], eax
|
||
|
mov dword [edi+mtrr_range.length+4], edx
|
||
|
.truncate_uc_done:
|
||
|
; 6g. We have found the next range (maybe 0) after intersection.
|
||
|
; Write it to [esi+mtrr_range.next].
|
||
|
mov [esi+mtrr_range.next], edi
|
||
|
.next_uc_range:
|
||
|
; 6h. Continue the loop 6b-6g over all configured MTRRs.
|
||
|
add ecx, 16
|
||
|
cmp ecx, [.mtrrs_end]
|
||
|
jb .fill_uc_ranges
|
||
|
; Sanity check: if there are no ranges after steps 5-6,
|
||
|
; fallback to step 7. Otherwise, go to 8.
|
||
|
cmp [.first_range], 0
|
||
|
jnz .ranges_ok
|
||
|
.fill_ranges_from_memory_map:
|
||
|
; 7. BIOS has not configured variable-range MTRRs.
|
||
|
; Create one range from 0 to [MEM_AMOUNT].
|
||
|
mov eax, [.first_free_range]
|
||
|
mov edx, [eax+mtrr_range.next]
|
||
|
mov [.first_free_range], edx
|
||
|
mov [.first_range], eax
|
||
|
xor edx, edx
|
||
|
mov [eax+mtrr_range.next], edx
|
||
|
mov dword [eax+mtrr_range.start], edx
|
||
|
mov dword [eax+mtrr_range.start+4], edx
|
||
|
mov ecx, [MEM_AMOUNT]
|
||
|
mov dword [eax+mtrr_range.length], ecx
|
||
|
mov dword [eax+mtrr_range.length+4], edx
|
||
|
.ranges_ok:
|
||
|
; 8. We have calculated list of WB-ranges.
|
||
|
; Now we should calculate a list of MTRRs so that
|
||
|
; * every MTRR describes a range with length = power of 2 and start that is aligned,
|
||
|
; * every MTRR can be WB or UC
|
||
|
; * (sum of all WB ranges) minus (sum of all UC ranges) equals the calculated list
|
||
|
; * top of 4G memory must not be covered by any ranges
|
||
|
; Example: range [0,0xBC000000) can be converted to
|
||
|
; [0,0x80000000)+[0x80000000,0xC0000000)-[0xBC000000,0xC0000000)
|
||
|
; WB +WB -UC
|
||
|
; but not to [0,0x100000000)-[0xC0000000,0x100000000)-[0xBC000000,0xC0000000).
|
||
|
; 8a. Check that list of ranges is [0,something) plus, optionally, [4G,something).
|
||
|
; This holds in practice (see mtrrtest.asm for real-life examples)
|
||
|
; and significantly simplifies the code: ranges are independent, start of range
|
||
|
; is almost always aligned (the only exception >4G upper memory can be easily covered),
|
||
|
; there is no need to consider adding holes before start of range, only
|
||
|
; append them to end of range.
|
||
|
xor eax, eax
|
||
|
mov edi, [.first_range]
|
||
|
cmp dword [edi+mtrr_range.start], eax
|
||
|
jnz .abort
|
||
|
cmp dword [edi+mtrr_range.start+4], eax
|
||
|
jnz .abort
|
||
|
cmp dword [edi+mtrr_range.length+4], eax
|
||
|
jnz .abort
|
||
|
mov edx, [edi+mtrr_range.next]
|
||
|
test edx, edx
|
||
|
jz @f
|
||
|
cmp dword [edx+mtrr_range.start], eax
|
||
|
jnz .abort
|
||
|
cmp dword [edx+mtrr_range.start+4], 1
|
||
|
jnz .abort
|
||
|
cmp [edx+mtrr_range.next], eax
|
||
|
jnz .abort
|
||
|
@@:
|
||
|
; 8b. Initialize: no MTRRs filled.
|
||
|
mov [.num_used_mtrrs], eax
|
||
|
lea esi, [.mtrrs]
|
||
|
.range2mtrr_loop:
|
||
|
; 8c. If we are dealing with upper-memory range (after 4G)
|
||
|
; with length > start, create one WB MTRR with [start,2*start),
|
||
|
; reset start to 2*start and return to this step.
|
||
|
; Example: [4G,24G) -> [4G,8G) {returning} + [8G,16G) {returning}
|
||
|
; + [16G,24G) {advancing to ?}.
|
||
|
mov eax, dword [edi+mtrr_range.length+4]
|
||
|
test eax, eax
|
||
|
jz .less4G
|
||
|
mov edx, dword [edi+mtrr_range.start+4]
|
||
|
cmp eax, edx
|
||
|
jb .start_aligned
|
||
|
inc [.num_used_mtrrs]
|
||
|
cmp [.num_used_mtrrs], MAX_USEFUL_MTRRS
|
||
|
ja .abort
|
||
|
mov dword [esi], MEM_WB
|
||
|
mov dword [esi+4], edx
|
||
|
mov dword [esi+8], 0
|
||
|
mov dword [esi+12], edx
|
||
|
add esi, 16
|
||
|
add dword [edi+mtrr_range.start+4], edx
|
||
|
sub dword [edi+mtrr_range.length+4], edx
|
||
|
jnz .range2mtrr_loop
|
||
|
cmp dword [edi+mtrr_range.length], 0
|
||
|
jz .range2mtrr_next
|
||
|
.less4G:
|
||
|
; 8d. If we are dealing with low-memory range (before 4G)
|
||
|
; and appending a maximal-size hole would create a range covering top of 4G,
|
||
|
; create a maximal-size WB range and return to this step.
|
||
|
; Example: for [0,0xBC000000) the following steps would consider
|
||
|
; variants [0,0x80000000)+(another range to be splitted) and
|
||
|
; [0,0x100000000)-(another range to be splitted); we forbid the last variant,
|
||
|
; so the first variant must be used.
|
||
|
bsr ecx, dword [edi+mtrr_range.length]
|
||
|
xor edx, edx
|
||
|
inc edx
|
||
|
shl edx, cl
|
||
|
lea eax, [edx*2]
|
||
|
add eax, dword [edi+mtrr_range.start]
|
||
|
jnz .start_aligned
|
||
|
inc [.num_used_mtrrs]
|
||
|
cmp [.num_used_mtrrs], MAX_USEFUL_MTRRS
|
||
|
ja .abort
|
||
|
mov eax, dword [edi+mtrr_range.start]
|
||
|
mov dword [esi], eax
|
||
|
or dword [esi], MEM_WB
|
||
|
mov dword [esi+4], 0
|
||
|
mov dword [esi+8], edx
|
||
|
mov dword [esi+12], 0
|
||
|
add esi, 16
|
||
|
add dword [edi+mtrr_range.start], edx
|
||
|
sub dword [edi+mtrr_range.length], edx
|
||
|
jnz .less4G
|
||
|
jmp .range2mtrr_next
|
||
|
.start_aligned:
|
||
|
; Start is aligned for any allowed length, maximum-size hole is allowed.
|
||
|
; Select the best MTRR configuration for one range.
|
||
|
; length=...101101
|
||
|
; Without hole at the end, we need one WB MTRR for every 1-bit in length:
|
||
|
; length=...100000 + ...001000 + ...000100 + ...000001
|
||
|
; We can also append one hole at the end so that one 0-bit (selected by us)
|
||
|
; becomes 1 and all lower bits become 0 for WB-range:
|
||
|
; length=...110000 - (...00010 + ...00001)
|
||
|
; In this way, we need one WB MTRR for every 1-bit higher than the selected bit,
|
||
|
; one WB MTRR for the selected bit, one UC MTRR for every 0-bit between
|
||
|
; the selected bit and lowest 1-bit (they become 1-bits after negation)
|
||
|
; and one UC MTRR for lowest 1-bit.
|
||
|
; So we need to select 0-bit with the maximal difference
|
||
|
; (number of 0-bits) - (number of 1-bits) between selected and lowest 1-bit,
|
||
|
; this equals the gain from using a hole. If the difference is negative for
|
||
|
; all 0-bits, don't append hole.
|
||
|
; Note that lowest 1-bit is not included when counting, but selected 0-bit is.
|
||
|
; 8e. Find the optimal bit position for hole.
|
||
|
; eax = current difference, ebx = best difference,
|
||
|
; ecx = hole bit position, edx = current bit position.
|
||
|
xor eax, eax
|
||
|
xor ebx, ebx
|
||
|
xor ecx, ecx
|
||
|
bsf edx, dword [edi+mtrr_range.length]
|
||
|
jnz @f
|
||
|
bsf edx, dword [edi+mtrr_range.length+4]
|
||
|
add edx, 32
|
||
|
@@:
|
||
|
push edx ; save position of lowest 1-bit for step 8f
|
||
|
.calc_stat:
|
||
|
inc edx
|
||
|
cmp edx, 64
|
||
|
jae .stat_done
|
||
|
inc eax ; increment difference in hope for 1-bit
|
||
|
; Note: bt conveniently works with both .length and .length+4,
|
||
|
; depending on whether edx>=32.
|
||
|
bt dword [edi+mtrr_range.length], edx
|
||
|
jc .calc_stat
|
||
|
dec eax ; hope was wrong, decrement difference to correct 'inc'
|
||
|
dec eax ; and again, now getting the real difference
|
||
|
cmp eax, ebx
|
||
|
jle .calc_stat
|
||
|
mov ebx, eax
|
||
|
mov ecx, edx
|
||
|
jmp .calc_stat
|
||
|
.stat_done:
|
||
|
; 8f. If we decided to create a hole, flip all bits between lowest and selected.
|
||
|
pop edx ; restore position of lowest 1-bit saved at step 8e
|
||
|
test ecx, ecx
|
||
|
jz .fill_hi_init
|
||
|
@@:
|
||
|
inc edx
|
||
|
cmp edx, ecx
|
||
|
ja .fill_hi_init
|
||
|
btc dword [edi+mtrr_range.length], edx
|
||
|
jmp @b
|
||
|
.fill_hi_init:
|
||
|
; 8g. Create MTRR ranges corresponding to upper 32 bits.
|
||
|
sub ecx, 32
|
||
|
.fill_hi_loop:
|
||
|
bsr edx, dword [edi+mtrr_range.length+4]
|
||
|
jz .fill_hi_done
|
||
|
inc [.num_used_mtrrs]
|
||
|
cmp [.num_used_mtrrs], MAX_USEFUL_MTRRS
|
||
|
ja .abort
|
||
|
mov eax, dword [edi+mtrr_range.start]
|
||
|
mov [esi], eax
|
||
|
mov eax, dword [edi+mtrr_range.start+4]
|
||
|
mov [esi+4], eax
|
||
|
xor eax, eax
|
||
|
mov [esi+8], eax
|
||
|
bts eax, edx
|
||
|
mov [esi+12], eax
|
||
|
cmp edx, ecx
|
||
|
jl .fill_hi_uc
|
||
|
or dword [esi], MEM_WB
|
||
|
add dword [edi+mtrr_range.start+4], eax
|
||
|
jmp @f
|
||
|
.fill_hi_uc:
|
||
|
sub dword [esi+4], eax
|
||
|
sub dword [edi+mtrr_range.start+4], eax
|
||
|
@@:
|
||
|
add esi, 16
|
||
|
sub dword [edi+mtrr_range.length], eax
|
||
|
jmp .fill_hi_loop
|
||
|
.fill_hi_done:
|
||
|
; 8h. Create MTRR ranges corresponding to lower 32 bits.
|
||
|
add ecx, 32
|
||
|
.fill_lo_loop:
|
||
|
bsr edx, dword [edi+mtrr_range.length]
|
||
|
jz .range2mtrr_next
|
||
|
inc [.num_used_mtrrs]
|
||
|
cmp [.num_used_mtrrs], MAX_USEFUL_MTRRS
|
||
|
ja .abort
|
||
|
mov eax, dword [edi+mtrr_range.start]
|
||
|
mov [esi], eax
|
||
|
mov eax, dword [edi+mtrr_range.start+4]
|
||
|
mov [esi+4], eax
|
||
|
xor eax, eax
|
||
|
mov [esi+12], eax
|
||
|
bts eax, edx
|
||
|
mov [esi+8], eax
|
||
|
cmp edx, ecx
|
||
|
jl .fill_lo_uc
|
||
|
or dword [esi], MEM_WB
|
||
|
add dword [edi+mtrr_range.start], eax
|
||
|
jmp @f
|
||
|
.fill_lo_uc:
|
||
|
sub dword [esi], eax
|
||
|
sub dword [edi+mtrr_range.start], eax
|
||
|
@@:
|
||
|
add esi, 16
|
||
|
sub dword [edi+mtrr_range.length], eax
|
||
|
jmp .fill_lo_loop
|
||
|
.range2mtrr_next:
|
||
|
; 8i. Repeat the loop at 8c-8h for all ranges.
|
||
|
mov edi, [edi+mtrr_range.next]
|
||
|
test edi, edi
|
||
|
jnz .range2mtrr_loop
|
||
|
; 9. We have calculated needed MTRRs, now setup them in the CPU.
|
||
|
; 9a. Abort if number of MTRRs is too large.
|
||
|
mov eax, [num_variable_mtrrs]
|
||
|
cmp [.num_used_mtrrs], eax
|
||
|
ja .abort
|
||
|
|
||
|
; 9b. Prepare for changes.
|
||
|
call mtrr_begin_change
|
||
|
|
||
|
; 9c. Prepare for loop over MTRRs.
|
||
|
lea esi, [.mtrrs]
|
||
|
mov ecx, 0x200
|
||
|
@@:
|
||
|
; 9d. For every MTRR, copy PHYSBASEn as is: step 8 has configured
|
||
|
; start value and type bits as needed.
|
||
|
mov eax, [esi]
|
||
|
mov edx, [esi+4]
|
||
|
wrmsr
|
||
|
inc ecx
|
||
|
; 9e. For every MTRR, calculate PHYSMASKn = -(length) or 0x800
|
||
|
; with upper bits cleared, 0x800 = MTRR is valid.
|
||
|
xor eax, eax
|
||
|
xor edx, edx
|
||
|
sub eax, [esi+8]
|
||
|
sbb edx, [esi+12]
|
||
|
or eax, 0x800
|
||
|
or edx, [.phys_reserved_mask]
|
||
|
xor edx, [.phys_reserved_mask]
|
||
|
wrmsr
|
||
|
inc ecx
|
||
|
; 9f. Continue steps 9d and 9e for all MTRRs calculated at step 8.
|
||
|
add esi, 16
|
||
|
dec [.num_used_mtrrs]
|
||
|
jnz @b
|
||
|
; 9g. Zero other MTRRs.
|
||
|
xor eax, eax
|
||
|
xor edx, edx
|
||
|
mov ebx, [num_variable_mtrrs]
|
||
|
lea ebx, [0x200+ebx*2]
|
||
|
@@:
|
||
|
cmp ecx, ebx
|
||
|
jae @f
|
||
|
wrmsr
|
||
|
inc ecx
|
||
|
wrmsr
|
||
|
inc ecx
|
||
|
jmp @b
|
||
|
@@:
|
||
|
|
||
|
; 9i. Check PAT support and reprogram PAT_MASR for write combining memory
|
||
|
bt [cpu_caps], CAPS_PAT
|
||
|
jnc @F
|
||
|
|
||
|
mov ecx, MSR_CR_PAT
|
||
|
mov eax, PAT_VALUE ;UC UCM WC WB
|
||
|
mov edx, eax
|
||
|
wrmsr
|
||
|
@@:
|
||
|
|
||
|
; 9j. Changes are done.
|
||
|
call mtrr_end_change
|
||
|
|
||
|
.abort:
|
||
|
add esp, .local_vars_size + MAX_RANGES * sizeof.mtrr_range
|
||
|
pop ebp
|
||
|
ret
|
||
|
endp
|
||
|
|
||
|
; Allocate&set one MTRR for given range.
|
||
|
; size must be power of 2 that divides base.
|
||
|
proc set_mtrr stdcall, base:dword,size:dword,mem_type:dword
|
||
|
; find unused register
|
||
|
mov ecx, 0x201
|
||
|
.scan:
|
||
|
mov eax, [num_variable_mtrrs]
|
||
|
lea eax, [0x200+eax*2]
|
||
|
cmp ecx, eax
|
||
|
jae .ret
|
||
|
rdmsr
|
||
|
dec ecx
|
||
|
test ah, 8
|
||
|
jz .found
|
||
|
rdmsr
|
||
|
test edx, edx
|
||
|
jnz @f
|
||
|
and eax, not 0xFFF ; clear reserved bits
|
||
|
cmp eax, [base]
|
||
|
jz .ret
|
||
|
@@:
|
||
|
add ecx, 3
|
||
|
jmp .scan
|
||
|
; no free registers, ignore the call
|
||
|
.ret:
|
||
|
ret
|
||
|
.found:
|
||
|
; found, write values
|
||
|
push ecx
|
||
|
call mtrr_begin_change
|
||
|
pop ecx
|
||
|
xor edx, edx
|
||
|
mov eax, [base]
|
||
|
or eax, [mem_type]
|
||
|
wrmsr
|
||
|
|
||
|
mov al, [cpu_phys_addr_width]
|
||
|
xor edx, edx
|
||
|
bts edx, eax
|
||
|
xor eax, eax
|
||
|
sub eax, [size]
|
||
|
sbb edx, 0
|
||
|
or eax, 0x800
|
||
|
inc ecx
|
||
|
wrmsr
|
||
|
call mtrr_end_change
|
||
|
ret
|
||
|
endp
|
||
|
|
||
|
; Helper procedure for mtrr_validate.
|
||
|
; Calculates memory type for given address according to variable-range MTRRs.
|
||
|
; Assumes that MTRRs are enabled.
|
||
|
; in: ebx = 32-bit physical address
|
||
|
; out: eax = memory type for ebx
|
||
|
proc mtrr_get_real_type
|
||
|
; 1. Initialize: we have not yet found any MTRRs covering ebx.
|
||
|
push 0
|
||
|
mov ecx, 0x201
|
||
|
.mtrr_loop:
|
||
|
; 2. For every MTRR, check whether it is valid; if not, continue to the next MTRR.
|
||
|
rdmsr
|
||
|
dec ecx
|
||
|
test ah, 8
|
||
|
jz .next
|
||
|
; 3. For every valid MTRR, check whether (ebx and PHYSMASKn) == PHYSBASEn,
|
||
|
; excluding low 12 bits.
|
||
|
and eax, ebx
|
||
|
push eax
|
||
|
rdmsr
|
||
|
test edx, edx
|
||
|
pop edx
|
||
|
jnz .next
|
||
|
xor edx, eax
|
||
|
and edx, not 0xFFF
|
||
|
jnz .next
|
||
|
; 4. If so, set the bit corresponding to memory type defined by this MTRR.
|
||
|
and eax, 7
|
||
|
bts [esp], eax
|
||
|
.next:
|
||
|
; 5. Continue loop at 2-4 for all variable-range MTRRs.
|
||
|
add ecx, 3
|
||
|
mov eax, [num_variable_mtrrs]
|
||
|
lea eax, [0x200+eax*2]
|
||
|
cmp ecx, eax
|
||
|
jb .mtrr_loop
|
||
|
; 6. If no MTRRs cover address in ebx, use default MTRR type from MTRR_DEF_CAP.
|
||
|
pop edx
|
||
|
test edx, edx
|
||
|
jz .default
|
||
|
; 7. Find&clear 1-bit in edx.
|
||
|
bsf eax, edx
|
||
|
btr edx, eax
|
||
|
; 8. If there was only one 1-bit, then all MTRRs are consistent, return that bit.
|
||
|
test edx, edx
|
||
|
jz .nothing
|
||
|
; Otherwise, return MEM_UC (e.g. WB+UC is UC).
|
||
|
xor eax, eax
|
||
|
.nothing:
|
||
|
ret
|
||
|
.default:
|
||
|
mov ecx, 0x2FF
|
||
|
rdmsr
|
||
|
movzx eax, al
|
||
|
ret
|
||
|
endp
|
||
|
|
||
|
; If MTRRs are configured improperly, this is not obvious to the user;
|
||
|
; everything works, but the performance can be horrible.
|
||
|
; Try to detect this and let the user know that the low performance
|
||
|
; is caused by some problem and is not a global property of the system.
|
||
|
; Let's hope he would report it to developers...
|
||
|
proc mtrr_validate
|
||
|
; 1. If MTRRs are not supported, they cannot be configured improperly.
|
||
|
; Note: VirtualBox claims MTRR support in cpuid, but emulates MTRRCAP=0,
|
||
|
; which is efficiently equivalent to absent MTRRs.
|
||
|
; So check [num_variable_mtrrs] instead of CAPS_MTRR in [cpu_caps].
|
||
|
cmp [num_variable_mtrrs], 0
|
||
|
jz .exit
|
||
|
; 2. If variable-range MTRRs are not configured, this is a problem.
|
||
|
mov ecx, 0x2FF
|
||
|
rdmsr
|
||
|
test ah, 8
|
||
|
jz .fail
|
||
|
; 3. Get the memory type for address somewhere inside working memory.
|
||
|
; It must be write-back.
|
||
|
mov ebx, 0x27FFFF
|
||
|
call mtrr_get_real_type
|
||
|
cmp al, MEM_WB
|
||
|
jnz .fail
|
||
|
; 4. If we're using a mode with LFB,
|
||
|
; get the memory type for last pixel of the framebuffer.
|
||
|
; It must be write-combined.
|
||
|
test word [SCR_MODE], 0x4000
|
||
|
jz .exit
|
||
|
mov eax, [_display.lfb_pitch]
|
||
|
mul [_display.height]
|
||
|
dec eax
|
||
|
; LFB is mapped to virtual address LFB_BASE,
|
||
|
; it uses global pages if supported by CPU.
|
||
|
mov ebx, [sys_proc+PROC.pdt_0+(LFB_BASE shr 20)]
|
||
|
test ebx, PDE_LARGE
|
||
|
jnz @f
|
||
|
mov ebx, [page_tabs+(LFB_BASE shr 10)]
|
||
|
@@:
|
||
|
and ebx, not 0xFFF
|
||
|
add ebx, eax
|
||
|
call mtrr_get_real_type
|
||
|
cmp al, MEM_WC
|
||
|
jz .exit
|
||
|
; 5. The check at step 4 fails on Bochs:
|
||
|
; Bochs BIOS configures MTRRs in a strange way not respecting [cpu_phys_addr_width],
|
||
|
; so mtrr_reconfigure avoids to touch anything.
|
||
|
; However, Bochs core ignores MTRRs (keeping them only for rdmsr/wrmsr),
|
||
|
; so we don't care about proper setting for Bochs.
|
||
|
; Use northbridge PCI id to detect Bochs: it emulates either i440fx or i430fx
|
||
|
; depending on configuration file.
|
||
|
mov eax, [pcidev_list.fd]
|
||
|
cmp eax, pcidev_list ; sanity check: fail if no PCI devices
|
||
|
jz .fail
|
||
|
cmp [eax+PCIDEV.vendor_device_id], 0x12378086
|
||
|
jz .exit
|
||
|
cmp [eax+PCIDEV.vendor_device_id], 0x01228086
|
||
|
jnz .fail
|
||
|
.exit:
|
||
|
ret
|
||
|
.fail:
|
||
|
mov ebx, mtrr_user_message
|
||
|
mov ebp, notifyapp
|
||
|
call fs_execute_from_sysdir_param
|
||
|
ret
|
||
|
endp
|