void build_legacy_cpu_hotplug_aml(Aml *ctx, MachineState *machine,

                                  uint16_t io_base, uint16_t io_len)

{

    Aml *dev;

    Aml *crs;

    Aml *pkg;

    Aml *field;

    Aml *method;

    Aml *if_ctx;

    Aml *else_ctx;

    int i, apic_idx;

    Aml *sb_scope = aml_scope("_SB");

    uint8_t madt_tmpl[8] = {0x00, 0x08, 0x00, 0x00, 0x00, 0, 0, 0};

    Aml *cpu_id = aml_arg(0);

    Aml *cpu_on = aml_local(0);

    Aml *madt = aml_local(1);

    Aml *cpus_map = aml_name(CPU_ON_BITMAP);

    Aml *zero = aml_int(0);

    Aml *one = aml_int(1);

    MachineClass *mc = MACHINE_GET_CLASS(machine);

    CPUArchIdList *apic_ids = mc->possible_cpu_arch_ids(machine);

    PCMachineState *pcms = PC_MACHINE(machine);



    /*

     * _MAT method - creates an madt apic buffer

     * cpu_id = Arg0 = Processor ID = Local APIC ID

     * cpu_on = Local0 = CPON flag for this cpu

     * madt = Local1 = Buffer (in madt apic form) to return

     */

    method = aml_method(CPU_MAT_METHOD, 1, AML_NOTSERIALIZED);

    aml_append(method,

        aml_store(aml_derefof(aml_index(cpus_map, cpu_id)), cpu_on));

    aml_append(method,

        aml_store(aml_buffer(sizeof(madt_tmpl), madt_tmpl), madt));

    /* Update the processor id, lapic id, and enable/disable status */

    aml_append(method, aml_store(cpu_id, aml_index(madt, aml_int(2))));

    aml_append(method, aml_store(cpu_id, aml_index(madt, aml_int(3))));

    aml_append(method, aml_store(cpu_on, aml_index(madt, aml_int(4))));

    aml_append(method, aml_return(madt));

    aml_append(sb_scope, method);



    /*

     * _STA method - return ON status of cpu

     * cpu_id = Arg0 = Processor ID = Local APIC ID

     * cpu_on = Local0 = CPON flag for this cpu

     */

    method = aml_method(CPU_STATUS_METHOD, 1, AML_NOTSERIALIZED);

    aml_append(method,

        aml_store(aml_derefof(aml_index(cpus_map, cpu_id)), cpu_on));

    if_ctx = aml_if(cpu_on);

    {

        aml_append(if_ctx, aml_return(aml_int(0xF)));

    }

    aml_append(method, if_ctx);

    else_ctx = aml_else();

    {

        aml_append(else_ctx, aml_return(zero));

    }

    aml_append(method, else_ctx);

    aml_append(sb_scope, method);



    method = aml_method(CPU_EJECT_METHOD, 2, AML_NOTSERIALIZED);

    aml_append(method, aml_sleep(200));

    aml_append(sb_scope, method);



    method = aml_method(CPU_SCAN_METHOD, 0, AML_NOTSERIALIZED);

    {

        Aml *while_ctx, *if_ctx2, *else_ctx2;

        Aml *bus_check_evt = aml_int(1);

        Aml *remove_evt = aml_int(3);

        Aml *status_map = aml_local(5); /* Local5 = active cpu bitmap */

        Aml *byte = aml_local(2); /* Local2 = last read byte from bitmap */

        Aml *idx = aml_local(0); /* Processor ID / APIC ID iterator */

        Aml *is_cpu_on = aml_local(1); /* Local1 = CPON flag for cpu */

        Aml *status = aml_local(3); /* Local3 = active state for cpu */



        aml_append(method, aml_store(aml_name(CPU_STATUS_MAP), status_map));

        aml_append(method, aml_store(zero, byte));

        aml_append(method, aml_store(zero, idx));



        /* While (idx < SizeOf(CPON)) */

        while_ctx = aml_while(aml_lless(idx, aml_sizeof(cpus_map)));

        aml_append(while_ctx,

            aml_store(aml_derefof(aml_index(cpus_map, idx)), is_cpu_on));



        if_ctx = aml_if(aml_and(idx, aml_int(0x07), NULL));

        {

            /* Shift down previously read bitmap byte */

            aml_append(if_ctx, aml_shiftright(byte, one, byte));

        }

        aml_append(while_ctx, if_ctx);



        else_ctx = aml_else();

        {

            /* Read next byte from cpu bitmap */

            aml_append(else_ctx, aml_store(aml_derefof(aml_index(status_map,

                       aml_shiftright(idx, aml_int(3), NULL))), byte));

        }

        aml_append(while_ctx, else_ctx);



        aml_append(while_ctx, aml_store(aml_and(byte, one, NULL), status));

        if_ctx = aml_if(aml_lnot(aml_equal(is_cpu_on, status)));

        {

            /* State change - update CPON with new state */

            aml_append(if_ctx, aml_store(status, aml_index(cpus_map, idx)));

            if_ctx2 = aml_if(aml_equal(status, one));

            {

                aml_append(if_ctx2,

                    aml_call2(AML_NOTIFY_METHOD, idx, bus_check_evt));

            }

            aml_append(if_ctx, if_ctx2);

            else_ctx2 = aml_else();

            {

                aml_append(else_ctx2,

                    aml_call2(AML_NOTIFY_METHOD, idx, remove_evt));

            }

        }

        aml_append(if_ctx, else_ctx2);

        aml_append(while_ctx, if_ctx);



        aml_append(while_ctx, aml_increment(idx)); /* go to next cpu */

        aml_append(method, while_ctx);

    }

    aml_append(sb_scope, method);



    /* The current AML generator can cover the APIC ID range [0..255],

     * inclusive, for VCPU hotplug. */

    QEMU_BUILD_BUG_ON(ACPI_CPU_HOTPLUG_ID_LIMIT > 256);

    g_assert(pcms->apic_id_limit <= ACPI_CPU_HOTPLUG_ID_LIMIT);



    /* create PCI0.PRES device and its _CRS to reserve CPU hotplug MMIO */

    dev = aml_device("PCI0." stringify(CPU_HOTPLUG_RESOURCE_DEVICE));

    aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A06")));

    aml_append(dev,

        aml_name_decl("_UID", aml_string("CPU Hotplug resources"))

    );

    /* device present, functioning, decoding, not shown in UI */

    aml_append(dev, aml_name_decl("_STA", aml_int(0xB)));

    crs = aml_resource_template();

    aml_append(crs,

        aml_io(AML_DECODE16, io_base, io_base, 1, io_len)

    );

    aml_append(dev, aml_name_decl("_CRS", crs));

    aml_append(sb_scope, dev);

    /* declare CPU hotplug MMIO region and PRS field to access it */

    aml_append(sb_scope, aml_operation_region(

        "PRST", AML_SYSTEM_IO, aml_int(io_base), io_len));

    field = aml_field("PRST", AML_BYTE_ACC, AML_NOLOCK, AML_PRESERVE);

    aml_append(field, aml_named_field("PRS", 256));

    aml_append(sb_scope, field);



    /* build Processor object for each processor */

    for (i = 0; i < apic_ids->len; i++) {

        int apic_id = apic_ids->cpus[i].arch_id;



        assert(apic_id < ACPI_CPU_HOTPLUG_ID_LIMIT);



        dev = aml_processor(apic_id, 0, 0, "CP%.02X", apic_id);



        method = aml_method("_MAT", 0, AML_NOTSERIALIZED);

        aml_append(method,

            aml_return(aml_call1(CPU_MAT_METHOD, aml_int(apic_id))));

        aml_append(dev, method);



        method = aml_method("_STA", 0, AML_NOTSERIALIZED);

        aml_append(method,

            aml_return(aml_call1(CPU_STATUS_METHOD, aml_int(apic_id))));

        aml_append(dev, method);



        method = aml_method("_EJ0", 1, AML_NOTSERIALIZED);

        aml_append(method,

            aml_return(aml_call2(CPU_EJECT_METHOD, aml_int(apic_id),

                aml_arg(0)))

        );

        aml_append(dev, method);



        aml_append(sb_scope, dev);

    }



    /* build this code:

     *   Method(NTFY, 2) {If (LEqual(Arg0, 0x00)) {Notify(CP00, Arg1)} ...}

     */

    /* Arg0 = Processor ID = APIC ID */

    method = aml_method(AML_NOTIFY_METHOD, 2, AML_NOTSERIALIZED);

    for (i = 0; i < apic_ids->len; i++) {

        int apic_id = apic_ids->cpus[i].arch_id;



        if_ctx = aml_if(aml_equal(aml_arg(0), aml_int(apic_id)));

        aml_append(if_ctx,

            aml_notify(aml_name("CP%.02X", apic_id), aml_arg(1))

        );

        aml_append(method, if_ctx);

    }

    aml_append(sb_scope, method);



    /* build "Name(CPON, Package() { One, One, ..., Zero, Zero, ... })"

     *

     * Note: The ability to create variable-sized packages was first

     * introduced in ACPI 2.0. ACPI 1.0 only allowed fixed-size packages

     * ith up to 255 elements. Windows guests up to win2k8 fail when

     * VarPackageOp is used.

     */

    pkg = pcms->apic_id_limit <= 255 ? aml_package(pcms->apic_id_limit) :

                                       aml_varpackage(pcms->apic_id_limit);



    for (i = 0, apic_idx = 0; i < apic_ids->len; i++) {

        int apic_id = apic_ids->cpus[i].arch_id;



        for (; apic_idx < apic_id; apic_idx++) {

            aml_append(pkg, aml_int(0));

        }

        aml_append(pkg, aml_int(apic_ids->cpus[i].cpu ? 1 : 0));

        apic_idx = apic_id + 1;

    }

    aml_append(sb_scope, aml_name_decl(CPU_ON_BITMAP, pkg));

    g_free(apic_ids);



    aml_append(ctx, sb_scope);



    method = aml_method("\\_GPE._E02", 0, AML_NOTSERIALIZED);

    aml_append(method, aml_call0("\\_SB." CPU_SCAN_METHOD));

    aml_append(ctx, method);

}
