diff --git a/bochs/.bochsrc b/bochs/.bochsrc
index 7ce476471..3f679e632 100644
--- a/bochs/.bochsrc
+++ b/bochs/.bochsrc
@@ -115,6 +115,7 @@
#
# CPU configurations that can be selected:
# -----------------------------------------------------------------
+# i486dx4 Intel 486DX4
# pentium Intel Pentium (P54C)
# pentium_mmx Intel Pentium MMX
# amd_k6_2_chomper AMD-K6(tm) 3D processor (Chomper)
diff --git a/bochs/CHANGES b/bochs/CHANGES
index 4193f530a..3c30568ef 100644
--- a/bochs/CHANGES
+++ b/bochs/CHANGES
@@ -6,6 +6,7 @@ Brief summary :
- Implemented MONITORLESS MWAIT instructions support
- Implemented AMX-TF32 ISA extension
- Added initial support for AVX10_1 ISA extension and AVX10 CPUID leaf 0x24 (to be enabled in Xeon Granite Rapids)
+ - CPUID: Added i486DX4 CPU definition
- CPUID: Added Arrow Lake CPU definition
- CPUID: Support for enabling/disabling of one of more CPU features from CPUID configuration (see "add_features" and "exclude_features" in bochsrc sample and documentation)
- Bugfixes for CPU emulation correctness (critical bugfixes for WAITPKG, LASS, XSAVEC/XSAVES, CPUID and SHA1 ISA implementation)
@@ -27,6 +28,8 @@ Detailed change log :
- Added initial support for AVX10_1 ISA extension and AVX10 CPUID leaf 0x24 (to be enabled in Xeon Granite Rapids)
- CPUID:
+ - Added i486DX4 CPU definition
+ - Model=4, supports x87 FPU and VME only
- Added Arrow Lake CPU definition
- Features AVX-VNNI, AVX-IFMA, AVX-VNNI-INT8, AVX-VNNI-INT16, AVX_NE_CONVERT, GFNI, VAES/VPCLMULQDQ, SHA512, SM3/SM4, CMPCCXADD, LASS, SERIALIZE, UINTR
- Support for enabling/disabling of one of more CPU features from CPUID configuration (see "add_features" and "exclude_features" in bochsrc sample and documentation)
diff --git a/bochs/cpu/cpudb/Makefile.in b/bochs/cpu/cpudb/Makefile.in
index e2f60a229..f1905a769 100644
--- a/bochs/cpu/cpudb/Makefile.in
+++ b/bochs/cpu/cpudb/Makefile.in
@@ -36,7 +36,8 @@ RANLIB = @RANLIB@
BX_INCDIRS = -I.. -I../.. -I$(srcdir)/.. -I$(srcdir)/../.. -I../../@INSTRUMENT_DIR@ -I$(srcdir)/../../@INSTRUMENT_DIR@
-CPUDB_OBJS = intel/pentium.o \
+CPUDB_OBJS = intel/i486dx4.o \
+ intel/pentium.o \
intel/pentium_mmx.o \
intel/p2_klamath.o \
intel/p3_katmai.o \
@@ -94,6 +95,15 @@ dist-clean: clean
# dependencies generated by
# gcc -MM -I.. -I../.. -I../../instrument/stubs */*.cc | sed 's/\.cc/.@CPP_SUFFIX@/g'
###########################################
+intel/i486dx4.o: intel/i486dx4.@CPP_SUFFIX@ ../../bochs.h ../../config.h ../../osdep.h \
+ ../../logio.h ../../misc/bswap.h ../cpu.h ../../bx_debug/debug.h \
+ ../../config.h ../../osdep.h ../../cpu/decoder/decoder.h \
+ ../../cpu/decoder/features.h ../decoder/decoder.h \
+ ../../instrument/stubs/instrument.h ../i387.h \
+ ../softfloat3e/include/softfloat_types.h ../fpu/tag_w.h \
+ ../fpu/status_w.h ../fpu/control_w.h ../crregs.h ../descriptor.h \
+ ../decoder/instr.h ../lazy_flags.h ../tlb.h ../icache.h ../xmm.h \
+ ../vmx.h ../vmx_ctrls.h ../access.h intel/i486dx4.h ../../cpu/cpuid.h
amd/amd_k6_2_chomper.o: amd/amd_k6_2_chomper.@CPP_SUFFIX@ ../../bochs.h ../../config.h \
../../osdep.h ../../logio.h ../../misc/bswap.h ../cpu.h \
../../bx_debug/debug.h ../../config.h ../../osdep.h \
diff --git a/bochs/cpu/cpudb/intel/i486dx4.cc b/bochs/cpu/cpudb/intel/i486dx4.cc
new file mode 100644
index 000000000..2af2d63a8
--- /dev/null
+++ b/bochs/cpu/cpudb/intel/i486dx4.cc
@@ -0,0 +1,117 @@
+/////////////////////////////////////////////////////////////////////////
+// $Id$
+/////////////////////////////////////////////////////////////////////////
+//
+// Copyright (c) 2024 Stanislav Shwartsman
+// Written by Stanislav Shwartsman [sshwarts at sourceforge net]
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA B 02110-1301 USA
+//
+/////////////////////////////////////////////////////////////////////////
+
+#include "bochs.h"
+#include "cpu.h"
+#include "i486dx4.h"
+
+#if BX_CPU_LEVEL >= 4
+
+#define LOG_THIS cpu->
+
+// used https://www.ardent-tool.com/CPU/Docs_Intel.html#CPUID as source
+
+// CPUID 00000000: 00000001-756E6547-6C65746E-49656E69
+// CPUID 00000001: 00000480-00000000-00000000-00000003
+
+i486dx4_t::i486dx4_t(BX_CPU_C *cpu): bx_cpuid_t(cpu)
+{
+ enable_cpu_extension(BX_ISA_X87);
+ enable_cpu_extension(BX_ISA_486);
+ enable_cpu_extension(BX_ISA_VME);
+}
+
+void i486dx4_t::get_cpuid_leaf(Bit32u function, Bit32u subfunction, cpuid_function_t *leaf) const
+{
+ switch(function) {
+ case 0x00000000:
+ get_leaf_0(0x1, "GenuineIntel", leaf);
+ return;
+ case 0x00000001:
+ default:
+ get_std_cpuid_leaf_1(leaf);
+ return;
+ }
+}
+
+// leaf 0x00000000 //
+
+// leaf 0x00000001 //
+void i486dx4_t::get_std_cpuid_leaf_1(cpuid_function_t *leaf) const
+{
+ // EAX: CPU Version Information
+ // [3:0] Stepping ID
+ // [7:4] Model: starts at 1
+ // [11:8] Family: 4=486, 5=Pentium, 6=PPro, ...
+ // [13:12] Type: 0=OEM, 1=overdrive, 2=dual cpu, 3=reserved
+ // [19:16] Extended Model
+ // [27:20] Extended Family
+ leaf->eax = 0x00000480;
+
+ leaf->ebx = 0;
+ leaf->ecx = 0;
+
+ // EDX: Standard Feature Flags
+ // * [0:0] FPU on chip
+ // * [1:1] VME: Virtual-8086 Mode enhancements
+ // [2:2] DE: Debug Extensions (I/O breakpoints)
+ // [3:3] PSE: Page Size Extensions
+ // [4:4] TSC: Time Stamp Counter
+ // [5:5] MSR: RDMSR and WRMSR support
+ // [6:6] PAE: Physical Address Extensions
+ // [7:7] MCE: Machine Check Exception
+ // [8:8] CXS: CMPXCHG8B instruction
+ // [9:9] APIC: APIC on Chip
+ // [10:10] Reserved
+ // [11:11] SYSENTER/SYSEXIT support
+ // [12:12] MTRR: Memory Type Range Reg
+ // [13:13] PGE/PTE Global Bit
+ // [14:14] MCA: Machine Check Architecture
+ // [15:15] CMOV: Cond Mov/Cmp Instructions
+ // [16:16] PAT: Page Attribute Table
+ // [17:17] PSE-36: Physical Address Extensions
+ // [18:18] PSN: Processor Serial Number
+ // [19:19] CLFLUSH: CLFLUSH Instruction support
+ // [20:20] Reserved
+ // [21:21] DS: Debug Store
+ // [22:22] ACPI: Thermal Monitor and Software Controlled Clock Facilities
+ // [23:23] MMX Technology
+ // [24:24] FXSR: FXSAVE/FXRSTOR (also indicates CR4.OSFXSR is available)
+ // [25:25] SSE: SSE Extensions
+ // [26:26] SSE2: SSE2 Extensions
+ // [27:27] Self Snoop
+ // [28:28] Hyper Threading Technology
+ // [29:29] TM: Thermal Monitor
+ // [30:30] Reserved
+ // [31:31] PBE: Pending Break Enable
+ leaf->edx = get_std_cpuid_leaf_1_edx();
+}
+
+void i486dx4_t::dump_cpuid(void) const
+{
+ bx_cpuid_t::dump_cpuid(0x1, 0);
+}
+
+bx_cpuid_t *create_i486dx4_cpuid(BX_CPU_C *cpu) { return new i486dx4_t(cpu); }
+
+#endif
diff --git a/bochs/cpu/cpudb/intel/i486dx4.h b/bochs/cpu/cpudb/intel/i486dx4.h
new file mode 100644
index 000000000..b6af471f7
--- /dev/null
+++ b/bochs/cpu/cpudb/intel/i486dx4.h
@@ -0,0 +1,51 @@
+/////////////////////////////////////////////////////////////////////////
+// $Id$
+/////////////////////////////////////////////////////////////////////////
+//
+// Copyright (c) 2024 Stanislav Shwartsman
+// Written by Stanislav Shwartsman [sshwarts at sourceforge net]
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA B 02110-1301 USA
+//
+/////////////////////////////////////////////////////////////////////////
+
+#ifndef BX_486DX4_CPUID_DEFINITIONS_H
+#define BX_486DX4_CPUID_DEFINITIONS_H
+
+#if BX_CPU_LEVEL >= 4
+
+#include "cpu/cpuid.h"
+
+class i486dx4_t : public bx_cpuid_t {
+public:
+ i486dx4_t(BX_CPU_C *cpu);
+ virtual ~i486dx4_t() {}
+
+ // return CPU name
+ virtual const char *get_name(void) const { return "i486dx4"; }
+
+ virtual void get_cpuid_leaf(Bit32u function, Bit32u subfunction, cpuid_function_t *leaf) const;
+
+ virtual void dump_cpuid(void) const;
+
+private:
+ void get_std_cpuid_leaf_1(cpuid_function_t *leaf) const;
+};
+
+extern bx_cpuid_t *create_i486dx4_cpuid(BX_CPU_C *cpu);
+
+#endif // BX_CPU_LEVEL >= 4
+
+#endif
diff --git a/bochs/cpudb.h b/bochs/cpudb.h
index fe8c7033b..a037f96e6 100644
--- a/bochs/cpudb.h
+++ b/bochs/cpudb.h
@@ -22,6 +22,8 @@
/////////////////////////////////////////////////////////////////////////
bx_define_cpudb(bx_generic)
+#if BX_CPU_LEVEL >= 4
+bx_define_cpudb(i486dx4)
#if BX_CPU_LEVEL >= 5
bx_define_cpudb(pentium)
bx_define_cpudb(pentium_mmx)
@@ -59,3 +61,4 @@ bx_define_cpudb(arrow_lake)
#endif
#endif
#endif
+#endif
\ No newline at end of file
diff --git a/bochs/doc/docbook/user/user.dbk b/bochs/doc/docbook/user/user.dbk
index f97e391e9..91acf9fbe 100644
--- a/bochs/doc/docbook/user/user.dbk
+++ b/bochs/doc/docbook/user/user.dbk
@@ -5962,7 +5962,12 @@ features enabled at compile time (3rd column).
bx_genericDefault Bochs CPU configured with CPUID option
- cpu level 5
+ cpu level 4
+
+
+ i486dx4
+ Intel 486DX4
+ cpu level 4pentium