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foss-fpga-tools/third_party/Surelog/2b38692156ff2742b1c4c94d3b93df97f2145e0c/./SVIncCompil/Testcases/IbexGoogle/src/riscv_asm_program_gen.sv
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/*
* Copyright 2018 Google LLC
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
//-----------------------------------------------------------------------------------------
// RISC-V assembly program generator
//
// This is the main class to generate a complete RISC-V program, including the init routine,
// instruction section, data section, stack section, page table, interrupt and exception
// handling etc. Check gen_program() function to see how the program is generated.
//-----------------------------------------------------------------------------------------
class riscv_asm_program_gen extends uvm_object;
riscv_instr_gen_config cfg;
riscv_data_page_gen data_page_gen;
// User mode programs
riscv_instr_sequence main_program;
riscv_instr_sequence sub_program[];
riscv_instr_sequence debug_program;
riscv_instr_sequence debug_sub_program[];
// Kernel programs
// These programs are called in the interrupt/exception handling routine based on the privileged
// mode settings. For example, when the interrupt/exception is delegated to S-mode, if both SUM
// and MPRV equal 1, kernel program can fetch/load/store from U-mode pages,
// umode_program is designed for this purpose. There can be other cases that
// instruction can only be fetched from S-mode pages but load/store can access U-mode pages, or
// everything needs to be in S-mode pages.
riscv_instr_sequence umode_program;
riscv_instr_sequence smode_program;
riscv_instr_sequence smode_lsu_program;
riscv_instr_stream directed_instr[];
string instr_stream[$];
riscv_callstack_gen callstack_gen;
riscv_privileged_common_seq privil_seq;
// Directed instruction ratio, occurance per 1000 instructions
int unsigned directed_instr_stream_ratio[string];
riscv_page_table_list#(SATP_MODE) page_table_list;
`uvm_object_utils(riscv_asm_program_gen)
function new (string name = "");
super.new(name);
endfunction
//---------------------------------------------------------------------------------------
// Main function to generate the whole program
//---------------------------------------------------------------------------------------
// This is the main function to generate all sections of the program.
virtual function void gen_program();
string sub_program_name[$];
instr_stream.delete();
// Generate program header
gen_program_header();
// Initialize general purpose registers
init_gpr();
if (!cfg.bare_program_mode) begin
setup_misa();
// Create all page tables
create_page_table();
// Setup privileged mode registers and enter target privileged mode
pre_enter_privileged_mode();
end
// Init section
gen_init_section();
// Generate sub program
gen_sub_program(sub_program, sub_program_name, cfg.num_of_sub_program);
// Generate main program
main_program = riscv_instr_sequence::type_id::create("main_program");
main_program.instr_cnt = cfg.main_program_instr_cnt;
main_program.is_debug_program = 0;
main_program.label_name = "_main";
generate_directed_instr_stream(.label("main"),
.original_instr_cnt(main_program.instr_cnt),
.min_insert_cnt(1),
.instr_stream(main_program.directed_instr));
main_program.cfg = cfg;
`DV_CHECK_RANDOMIZE_FATAL(main_program)
main_program.gen_instr(.is_main_program(1), .no_branch(cfg.no_branch_jump));
// Setup jump instruction among main program and sub programs
gen_callstack(main_program, sub_program, sub_program_name, cfg.num_of_sub_program);
`uvm_info(`gfn, "Generating callstack...done", UVM_LOW)
main_program.post_process_instr();
`uvm_info(`gfn, "Post-processing main program...done", UVM_LOW)
main_program.generate_instr_stream();
`uvm_info(`gfn, "Generating main program instruction stream...done", UVM_LOW)
instr_stream = {instr_stream, main_program.instr_string_list};
// Test done section
gen_test_done();
// Shuffle the sub programs and insert to the instruction stream
insert_sub_program(sub_program, instr_stream);
`uvm_info(`gfn, "Inserting sub-programs...done", UVM_LOW)
`uvm_info(`gfn, "Main/sub program generation...done", UVM_LOW)
// Program end
gen_program_end();
if (!cfg.bare_program_mode) begin
// Privileged mode switch routine
gen_privileged_mode_switch_routine();
// Generate debug rom section
gen_debug_rom();
// Generate debug mode exception handler
gen_debug_exception_handler();
end
// Starting point of data section
gen_data_page_begin();
// Page table
if (!cfg.bare_program_mode) begin
gen_page_table_section();
end
if(!cfg.no_data_page) begin
// Kernel data section
gen_data_page();
end
gen_data_page_end();
// Stack section
gen_stack_section();
if (!cfg.bare_program_mode) begin
// Generate kernel program/data/stack section
gen_kernel_sections();
end
endfunction
//---------------------------------------------------------------------------------------
// Generate kernel program/data/stack sections
//---------------------------------------------------------------------------------------
virtual function void gen_kernel_sections();
instr_stream.push_back("_kernel_instr_start: .align 12");
instr_stream.push_back(".text");
// Kernel programs
if (cfg.virtual_addr_translation_on) begin
umode_program = riscv_instr_sequence::type_id::create("umode_program");
gen_kernel_program(umode_program);
smode_program = riscv_instr_sequence::type_id::create("smode_program");
gen_kernel_program(smode_program);
smode_lsu_program = riscv_instr_sequence::type_id::create("smode_lsu_program");
gen_kernel_program(smode_lsu_program);
end
// All trap/interrupt handling is in the kernel region
// Trap/interrupt delegation to user mode is not supported now
// Trap handler
gen_all_trap_handler();
// Interrupt handling subroutine
foreach(riscv_instr_pkg::supported_privileged_mode[i]) begin
gen_interrupt_handler_section(riscv_instr_pkg::supported_privileged_mode[i]);
end
instr_stream.push_back("_kernel_instr_end: nop");
// User stack and data pages may not be accessible when executing trap handling programs in
// machine/supervisor mode. Generate separate kernel data/stack sections to solve it.
if (cfg.virtual_addr_translation_on) begin
// Kernel data pages
instr_stream.push_back("_kernel_data_start: .align 12");
if(!cfg.no_data_page) begin
// Data section
gen_data_page(1'b1);
end
gen_data_page_end();
end
// Kernel stack section
gen_kernel_stack_section();
endfunction
virtual function void gen_kernel_program(riscv_instr_sequence seq);
seq.instr_cnt = cfg.kernel_program_instr_cnt;
generate_directed_instr_stream(.label(seq.get_name()),
.original_instr_cnt(seq.instr_cnt),
.min_insert_cnt(0),
.instr_stream(seq.directed_instr),
.kernel_mode(1'b1));
seq.label_name = seq.get_name();
seq.is_debug_program = 0;
seq.cfg = cfg;
`DV_CHECK_RANDOMIZE_FATAL(seq)
seq.gen_instr(.is_main_program(0), .no_branch(cfg.no_branch_jump));
seq.post_process_instr();
seq.generate_instr_stream();
instr_stream = {instr_stream, seq.instr_string_list};
endfunction
//---------------------------------------------------------------------------------------
// Generate any subprograms and set up the callstack
//---------------------------------------------------------------------------------------
virtual function void gen_sub_program(ref riscv_instr_sequence sub_program[],
ref string sub_program_name[$],
input int num_sub_program,
bit is_debug = 1'b0,
string prefix = "sub");
if(num_sub_program > 0) begin
sub_program = new[num_sub_program];
foreach(sub_program[i]) begin
sub_program[i] = riscv_instr_sequence::type_id::create($sformatf("%s_%0d",prefix,i+1));
`uvm_info(`gfn, $sformatf("sub program name: %s", prefix), UVM_LOW)
sub_program[i].is_debug_program = is_debug;
if (is_debug) begin
sub_program[i].instr_cnt = cfg.debug_sub_program_instr_cnt[i];
end else begin
sub_program[i].instr_cnt = cfg.sub_program_instr_cnt[i];
end
generate_directed_instr_stream(.label(sub_program[i].get_name()),
.original_instr_cnt(sub_program[i].instr_cnt),
.min_insert_cnt(0),
.instr_stream(sub_program[i].directed_instr));
sub_program[i].label_name = sub_program[i].get_name();
sub_program[i].cfg = cfg;
`DV_CHECK_RANDOMIZE_FATAL(sub_program[i])
sub_program[i].gen_instr(.is_main_program(0), .no_branch(cfg.no_branch_jump));
sub_program_name.push_back(sub_program[i].label_name);
end
end
endfunction
virtual function void gen_callstack(riscv_instr_sequence main_program,
ref riscv_instr_sequence sub_program[],
ref string sub_program_name[$],
input int num_sub_program);
if(num_sub_program != 0) begin
callstack_gen = riscv_callstack_gen::type_id::create("callstack_gen");
callstack_gen.init(num_sub_program+1);
`uvm_info(get_full_name(), "Randomizing call stack", UVM_LOW)
if(callstack_gen.randomize()) begin
program_id_t pid;
int idx;
// Insert the jump instruction based on the call stack
foreach(callstack_gen.program_h[i]) begin
foreach(callstack_gen.program_h[i].sub_program_id[j]) begin
idx++;
pid = callstack_gen.program_h[i].sub_program_id[j] - 1;
`uvm_info(get_full_name(), $sformatf(
"Gen jump instr %0d -> sub[%0d] %0d", i, j, pid+1), UVM_LOW)
if(i == 0)
main_program.insert_jump_instr(sub_program_name[pid], idx);
else
sub_program[i-1].insert_jump_instr(sub_program_name[pid], idx);
end
end
end else begin
`uvm_fatal(get_full_name(), "Failed to generate callstack")
end
end
`uvm_info(get_full_name(), "Randomizing call stack..done", UVM_LOW)
endfunction
virtual function void insert_sub_program(ref riscv_instr_sequence sub_program[],
ref string instr_list[$]);
sub_program.shuffle();
foreach(sub_program[i]) begin
sub_program[i].post_process_instr();
sub_program[i].generate_instr_stream();
instr_list = {instr_list, sub_program[i].instr_string_list};
end
endfunction
//---------------------------------------------------------------------------------------
// Major sections - init, stack, data, test_done etc.
//---------------------------------------------------------------------------------------
virtual function void gen_program_header();
instr_stream.push_back(".include \"user_define.h\"");
instr_stream.push_back(".globl _start");
instr_stream.push_back(".section .text");
if (cfg.disable_compressed_instr) begin
instr_stream.push_back(".option norvc;");
end
instr_stream.push_back("_start:");
endfunction
virtual function void gen_program_end();
// Use write_tohost to terminate spike simulation
gen_section("write_tohost", {"sw gp, tohost, t5"});
gen_section("_exit", {"j write_tohost"});
endfunction
virtual function void gen_data_page_begin();
instr_stream.push_back(".data");
instr_stream.push_back(".pushsection .tohost,\"aw\",@progbits;");
instr_stream.push_back(".align 6; .global tohost; tohost: .dword 0;");
instr_stream.push_back(".align 6; .global fromhost; fromhost: .dword 0;");
instr_stream.push_back(".popsection;");
endfunction
virtual function void gen_data_page(bit is_kernel = 1'b0);
string data_page;
data_page_gen = riscv_data_page_gen::type_id::create("data_page_gen");
data_page_gen.cfg = cfg;
data_page_gen.gen_data_page(cfg.data_page_pattern, is_kernel);
instr_stream = {instr_stream, data_page_gen.data_page_str};
endfunction
virtual function void gen_data_page_end();
instr_stream.push_back(".align 4;");
endfunction
// Generate the user stack section
virtual function void gen_stack_section();
instr_stream.push_back(".pushsection .user_stack,\"aw\",@progbits;");
instr_stream.push_back(".align 12");
instr_stream.push_back("_user_stack_start:");
instr_stream.push_back($sformatf(".rept %0d", cfg.stack_len - 1));
instr_stream.push_back($sformatf(".%0dbyte 0x0", XLEN/8));
instr_stream.push_back(".endr");
instr_stream.push_back("_user_stack_end:");
instr_stream.push_back($sformatf(".%0dbyte 0x0", XLEN/8));
instr_stream.push_back(".popsection;");
endfunction
// The kernal stack is used to save user program context before executing exception handling
virtual function void gen_kernel_stack_section();
instr_stream.push_back(".pushsection .kernel_stack,\"aw\",@progbits;");
instr_stream.push_back(".align 12");
instr_stream.push_back("_kernel_stack_start:");
instr_stream.push_back($sformatf(".rept %0d", cfg.kernel_stack_len - 1));
instr_stream.push_back($sformatf(".%0dbyte 0x0", XLEN/8));
instr_stream.push_back(".endr");
instr_stream.push_back("_kernel_stack_end:");
instr_stream.push_back($sformatf(".%0dbyte 0x0", XLEN/8));
instr_stream.push_back(".popsection;");
endfunction
virtual function void gen_init_section();
string str;
str = format_string("_init:", LABEL_STR_LEN);
instr_stream.push_back(str);
// Init stack pointer to point to the end of the user stack
str = {indent, $sformatf("la x%0d, _user_stack_end", cfg.sp)};
instr_stream.push_back(str);
if (cfg.enable_floating_point) begin
init_floating_point_gpr();
end
core_is_initialized();
gen_dummy_csr_write();
endfunction
// Setup MISA based on supported extensions
virtual function void setup_misa();
bit [XLEN-1:0] misa;
misa[XLEN-1:XLEN-2] = (XLEN == 32) ? 2'b01 :
(XLEN == 64) ? 2'b10 : 2'b11;
if (cfg.check_misa_init_val) begin
instr_stream.push_back({indent, "csrr x15, misa"});
end
foreach (supported_isa[i]) begin
case (supported_isa[i]) inside
RV32C, RV64C, RV128C : misa[MISA_EXT_C] = 1'b1;
RV32I, RV64I, RV128I : misa[MISA_EXT_I] = 1'b1;
RV32M, RV64M : misa[MISA_EXT_M] = 1'b1;
RV32A, RV64A : misa[MISA_EXT_A] = 1'b1;
RV32F, RV64F, RV32FC : misa[MISA_EXT_F] = 1'b1;
RV32D, RV64D, RV32DC : misa[MISA_EXT_D] = 1'b1;
default : `uvm_fatal(`gfn, $sformatf("%0s is not yet supported",
supported_isa[i].name()))
endcase
end
if (SUPERVISOR_MODE inside {supported_privileged_mode}) begin
misa[MISA_EXT_S] = 1'b1;
end
instr_stream.push_back({indent, $sformatf("li x%0d, 0x%0x",cfg.gpr[0], misa)});
instr_stream.push_back({indent, $sformatf("csrw misa, x%0d",cfg.gpr[0])});
endfunction
// Write to the signature_addr with values to indicate to the core testbench
// that is safe to start sending interrupt and debug stimulus
virtual function void core_is_initialized();
string instr[$];
if (cfg.require_signature_addr) begin
if (cfg.signature_addr != 32'hdead_beef) begin
gen_signature_handshake(instr, CORE_STATUS, INITIALIZED);
format_section(instr);
instr_stream = {instr_stream, instr};
end else begin
`uvm_fatal(`gfn, "The signature_addr is not properly configured!")
end
end
endfunction
// Generate some dummy writes to xSTATUS/xIE at the beginning of the test to check
// repeated writes to these CSRs.
virtual function void gen_dummy_csr_write();
string instr[$];
case (cfg.init_privileged_mode)
MACHINE_MODE: begin
instr.push_back($sformatf("csrr x%0d, 0x%0x", cfg.gpr[0], MSTATUS));
instr.push_back($sformatf("csrr x%0d, 0x%0x", cfg.gpr[1], MIE));
instr.push_back($sformatf("csrw 0x%0x, x%0d", MSTATUS, cfg.gpr[0]));
instr.push_back($sformatf("csrw 0x%0x, x%0d", MIE, cfg.gpr[1]));
end
SUPERVISOR_MODE: begin
instr.push_back($sformatf("csrr x%0d, 0x%0x", cfg.gpr[0], SSTATUS));
instr.push_back($sformatf("csrr x%0d, 0x%0x", cfg.gpr[1], SIE));
instr.push_back($sformatf("csrw 0x%0x, x%0d", SSTATUS, cfg.gpr[0]));
instr.push_back($sformatf("csrw 0x%0x, x%0d", SIE, cfg.gpr[1]));
end
USER_MODE: begin
instr.push_back($sformatf("csrr x%0d, 0x%0x", cfg.gpr[0], USTATUS));
instr.push_back($sformatf("csrr x%0d, 0x%0x", cfg.gpr[1], UIE));
instr.push_back($sformatf("csrw 0x%0x, x%0d", USTATUS, cfg.gpr[0]));
instr.push_back($sformatf("csrw 0x%0x, x%0d", UIE, cfg.gpr[1]));
end
default: begin
`uvm_fatal(`gfn, "Unsupported boot mode")
end
endcase
format_section(instr);
instr_stream = {instr_stream, instr};
endfunction
// Initialize general purpose registers with random value
virtual function void init_gpr();
string str;
bit [DATA_WIDTH-1:0] reg_val;
// Init general purpose registers with random values
for(int i = 0; i < 32; i++) begin
`DV_CHECK_STD_RANDOMIZE_WITH_FATAL(reg_val,
reg_val dist {
'h0 :/ 1,
'h8000_0000 :/ 1,
['h1 : 'hF] :/ 1,
['h10 : 'hEFFF_FFFF] :/ 1,
['hF000_0000 : 'hFFFF_FFFF] :/ 1
};)
str = $sformatf("%0sli x%0d, 0x%0x", indent, i, reg_val);
instr_stream.push_back(str);
end
endfunction
// Initialize floating point general purpose registers
virtual function void init_floating_point_gpr();
int int_gpr;
string str;
// TODO: Initialize floating point GPR with more interesting numbers
for(int i = 0; i < 32; i++) begin
int_gpr = $urandom_range(0, 31);
// Use a random integer GPR to initialize floating point GPR
if (RV64F inside {supported_isa}) begin
str = $sformatf("%0sfcvt.d.l f%0d, x%0d", indent, i, int_gpr);
end else begin
str = $sformatf("%0sfcvt.s.w f%0d, x%0d", indent, i, int_gpr);
end
instr_stream.push_back(str);
end
// Initialize rounding mode of FCSR
str = $sformatf("%0sfsrmi %0d", indent, cfg.fcsr_rm);
instr_stream.push_back(str);
endfunction
// Generate "test_done" section, test is finished by an ECALL instruction
// The ECALL trap handler will handle the clean up procedure before finishing the test.
virtual function void gen_test_done();
string str = format_string("test_done:", LABEL_STR_LEN);
instr_stream.push_back(str);
instr_stream.push_back({indent, "li gp, 1"});
if (cfg.bare_program_mode) begin
instr_stream.push_back({indent, "j write_tohost"});
end else begin
instr_stream.push_back({indent, "ecall"});
end
endfunction
// Dump all GPR to the starting point of the program
// TB can check the GPR value for this memory location to compare with expected value generated
// by the ISA simulator. If the processor doesn't have a good tracer unit, it might not be
// possible to compare the GPR value after each instruction execution.
virtual function void gen_register_dump();
string str;
// Load base address
str = {indent, $sformatf("la x%0d, _start", cfg.gpr[0])};
instr_stream.push_back(str);
// Generate sw/sd instructions
for(int i = 0; i < 32; i++) begin
if(XLEN == 64) begin
str = {indent, $sformatf("sd x%0d, %0d(x%0d)", i, i*(XLEN/8), cfg.gpr[0])};
end else begin
str = {indent, $sformatf("sw x%0d, %0d(x%0d)", i, i*(XLEN/8), cfg.gpr[0])};
end
instr_stream.push_back(str);
end
endfunction
//---------------------------------------------------------------------------------------
// Privileged mode entering routine
//---------------------------------------------------------------------------------------
virtual function void pre_enter_privileged_mode();
string instr[];
// Setup kerenal stack pointer
gen_section("kernel_sp", {$sformatf("la x%0d, _kernel_stack_end", cfg.tp)});
// Setup interrupt and exception delegation
if(!cfg.no_delegation && (cfg.init_privileged_mode != MACHINE_MODE)) begin
gen_delegation();
end
// Setup trap vector register
trap_vector_init();
// Initialize PTE (link page table based on their real physical address)
if(cfg.virtual_addr_translation_on) begin
page_table_list.process_page_table(instr);
gen_section("process_pt", instr);
end
// Setup mepc register, jump to init entry
setup_epc();
endfunction
virtual function void gen_privileged_mode_switch_routine();
privil_seq = riscv_privileged_common_seq::type_id::create("privil_seq");
foreach(riscv_instr_pkg::supported_privileged_mode[i]) begin
string instr[$];
string csr_handshake[$];
string ret_instr;
if(riscv_instr_pkg::supported_privileged_mode[i] < cfg.init_privileged_mode) continue;
`uvm_info(`gfn, $sformatf("Generating privileged mode routing for %0s",
riscv_instr_pkg::supported_privileged_mode[i].name()), UVM_LOW)
// Enter privileged mode
privil_seq.cfg = cfg;
`DV_CHECK_RANDOMIZE_FATAL(privil_seq)
privil_seq.enter_privileged_mode(riscv_instr_pkg::supported_privileged_mode[i], instr);
if (cfg.require_signature_addr) begin
ret_instr = instr.pop_back();
// Want to write the main system CSRs to the testbench before indicating that initialization
// is complete, for any initial state analysis
case(riscv_instr_pkg::supported_privileged_mode[i])
MACHINE_MODE: begin
gen_signature_handshake(.instr(csr_handshake), .signature_type(WRITE_CSR), .csr(MSTATUS));
gen_signature_handshake(.instr(csr_handshake), .signature_type(WRITE_CSR), .csr(MIE));
end
SUPERVISOR_MODE: begin
gen_signature_handshake(.instr(csr_handshake), .signature_type(WRITE_CSR), .csr(SSTATUS));
gen_signature_handshake(.instr(csr_handshake), .signature_type(WRITE_CSR), .csr(SIE));
end
USER_MODE: begin
gen_signature_handshake(.instr(csr_handshake), .signature_type(WRITE_CSR), .csr(USTATUS));
gen_signature_handshake(.instr(csr_handshake), .signature_type(WRITE_CSR), .csr(UIE));
end
endcase
format_section(csr_handshake);
instr = {instr, csr_handshake, ret_instr};
end
instr_stream = {instr_stream, instr};
end
endfunction
// Setup EPC before entering target privileged mode
virtual function void setup_epc();
string instr[];
string mode_name;
instr = {$sformatf("la x%0d, _init", cfg.gpr[0])};
if(cfg.virtual_addr_translation_on) begin
// For supervisor and user mode, use virtual address instead of physical address.
// Virtual address starts from address 0x0, here only the lower 12 bits are kept
// as virtual address offset.
instr = {instr,
$sformatf("slli x%0d, x%0d, %0d", cfg.gpr[0], cfg.gpr[0], XLEN - 12),
$sformatf("srli x%0d, x%0d, %0d", cfg.gpr[0], cfg.gpr[0], XLEN - 12)};
end
mode_name = cfg.init_privileged_mode.name();
instr = {instr,
$sformatf("csrw mepc, x%0d", cfg.gpr[0]),
$sformatf("j init_%0s", mode_name.tolower())
};
gen_section("mepc_setup", instr);
endfunction
//---------------------------------------------------------------------------------------
// Privileged CSR setup for interrupt and exception handling and delegation
//---------------------------------------------------------------------------------------
// Interrupt and exception delegation setting.
// The lower level exception and interrupt can be delegated to higher level handler.
virtual function void gen_delegation();
gen_delegation_instr(MEDELEG, MIDELEG,
cfg.m_mode_exception_delegation,
cfg.m_mode_interrupt_delegation);
if(riscv_instr_pkg::support_umode_trap) begin
gen_delegation_instr(SEDELEG, SIDELEG,
cfg.s_mode_exception_delegation,
cfg.s_mode_interrupt_delegation);
end
endfunction
virtual function void gen_delegation_instr(privileged_reg_t edeleg,
privileged_reg_t ideleg,
bit edeleg_enable[exception_cause_t],
bit ideleg_enable[interrupt_cause_t]);
bit [XLEN-1:0] deleg_val;
string section_name;
string instr[];
// Exception delegation setup
foreach(edeleg_enable[cause]) begin
if(edeleg_enable[cause]) begin
deleg_val = deleg_val | (1 << int'(cause));
end
end
instr = {$sformatf("li x%0d, 0x%0x", cfg.gpr[0], deleg_val),
$sformatf("csrw 0x%0x, x%0d # %0s", edeleg, cfg.gpr[0], edeleg.name())};
// Interrupt delegation setup
deleg_val = '0;
foreach(ideleg_enable[cause]) begin
if(ideleg_enable[cause]) begin
deleg_val = deleg_val | (1 << int'(cause));
end
end
instr = {instr,
$sformatf("li x%0d, 0x%0x", cfg.gpr[0], deleg_val),
$sformatf("csrw 0x%0x, x%0d # %0s", ideleg, cfg.gpr[0], ideleg.name())};
section_name = edeleg.name();
section_name = section_name.tolower();
gen_section($sformatf("%0s_setup", section_name), instr);
endfunction
// Setup trap vector - MTVEC, STVEC, UTVEC
virtual function void trap_vector_init();
string instr[];
privileged_reg_t trap_vec_reg;
string tvec_name;
foreach(riscv_instr_pkg::supported_privileged_mode[i]) begin
case(riscv_instr_pkg::supported_privileged_mode[i])
MACHINE_MODE: trap_vec_reg = MTVEC;
SUPERVISOR_MODE: trap_vec_reg = STVEC;
USER_MODE: trap_vec_reg = UTVEC;
endcase
// Skip utvec init if trap delegation to u_mode is not supported
if ((riscv_instr_pkg::supported_privileged_mode[i] == USER_MODE) &&
!riscv_instr_pkg::support_umode_trap) continue;
if (riscv_instr_pkg::supported_privileged_mode[i] < cfg.init_privileged_mode) continue;
tvec_name = trap_vec_reg.name();
instr = {instr, $sformatf("la x%0d, %0s_handler", cfg.gpr[0], tvec_name.tolower())};
if (SATP_MODE != BARE && riscv_instr_pkg::supported_privileged_mode[i] != MACHINE_MODE) begin
// For supervisor and user mode, use virtual address instead of physical address.
// Virtual address starts from address 0x0, here only the lower 20 bits are kept
// as virtual address offset.
instr = {instr,
$sformatf("slli x%0d, x%0d, %0d", cfg.gpr[0], cfg.gpr[0], XLEN - 20),
$sformatf("srli x%0d, x%0d, %0d", cfg.gpr[0], cfg.gpr[0], XLEN - 20)};
end
instr = {instr, $sformatf("ori x%0d, x%0d, %0d", cfg.gpr[0], cfg.gpr[0], cfg.mtvec_mode)};
instr = {instr, $sformatf("csrw 0x%0x, x%0d # %0s",
trap_vec_reg, cfg.gpr[0], trap_vec_reg.name())};
end
gen_section("trap_vec_init", instr);
endfunction
//---------------------------------------------------------------------------------------
// Exception handling routine
//---------------------------------------------------------------------------------------
// Trap handling routine
virtual function void gen_all_trap_handler();
string instr[$];
foreach(riscv_instr_pkg::supported_privileged_mode[i]) begin
if(riscv_instr_pkg::supported_privileged_mode[i] < cfg.init_privileged_mode) continue;
case(riscv_instr_pkg::supported_privileged_mode[i])
MACHINE_MODE:
gen_trap_handler_section("m", MCAUSE, MTVEC, MTVAL, MEPC, MSCRATCH, MSTATUS, MIE, MIP);
SUPERVISOR_MODE:
gen_trap_handler_section("s", SCAUSE, STVEC, STVAL, SEPC, SSCRATCH, SSTATUS, SIE, SIP);
USER_MODE:
if(riscv_instr_pkg::support_umode_trap)
gen_trap_handler_section("u", UCAUSE, UTVEC, UTVAL, UEPC, USCRATCH, USTATUS, UIE, UIP);
endcase
end
// Ebreak handler
gen_ebreak_handler();
// Ecall handler
gen_ecall_handler();
// Illegal instruction handler
gen_illegal_instr_handler();
// Instruction fault handler
gen_instr_fault_handler();
// Load fault handler
gen_load_fault_handler();
// Store fault handler
gen_store_fault_handler();
// Generate page table fault handling routine
// Page table fault is always handled in machine mode, as virtual address translation may be
// broken when page fault happens.
gen_signature_handshake(instr, CORE_STATUS, HANDLING_EXCEPTION);
if(page_table_list != null) begin
page_table_list.gen_page_fault_handling_routine(instr);
end else begin
instr.push_back("nop");
end
gen_section("pt_fault_handler", instr);
endfunction
// Generate the interrupt and trap handler for different privileged mode.
// The trap handler checks the xCAUSE to determine the type of the exception and jumps to
// corresponding exeception handling routine.
virtual function void gen_trap_handler_section(string mode,
privileged_reg_t cause, privileged_reg_t tvec,
privileged_reg_t tval, privileged_reg_t epc,
privileged_reg_t scratch, privileged_reg_t status,
privileged_reg_t ie, privileged_reg_t ip);
bit is_interrupt = 'b1;
string tvec_name;
string instr[$];
if (cfg.mtvec_mode == VECTORED) begin
gen_interrupt_vector_table(mode, status, cause, ie, ip, scratch, instr);
end else begin
// Push user mode GPR to kernel stack before executing exception handling, this is to avoid
// exception handling routine modify user program state unexpectedly
push_gpr_to_kernel_stack(status, scratch, cfg.mstatus_mprv, cfg.sp, cfg.tp, instr);
// Checking xStatus can be optional if ISS (like spike) has different implementation of certain
// fields compared with the RTL processor.
if (cfg.check_xstatus) begin
instr = {instr, $sformatf("csrr x%0d, 0x%0x # %0s", cfg.gpr[0], status, status.name())};
end
instr = {instr,
// Use scratch CSR to save a GPR value
// Check if the exception is caused by an interrupt, if yes, jump to interrupt handler
// Interrupt is indicated by xCause[XLEN-1]
$sformatf("csrr x%0d, 0x%0x # %0s", cfg.gpr[0], cause, cause.name()),
$sformatf("srli x%0d, x%0d, %0d", cfg.gpr[0], cfg.gpr[0], XLEN-1),
$sformatf("bne x%0d, x0, %0smode_intr_handler", cfg.gpr[0], mode)};
end
// The trap handler will occupy one 4KB page, it will be allocated one entry in the page table
// with a specific privileged mode.
instr_stream.push_back(".align 12");
tvec_name = tvec.name();
gen_section($sformatf("%0s_handler", tvec_name.tolower()), instr);
// Exception handler
instr = {};
if (cfg.mtvec_mode == VECTORED) begin
push_gpr_to_kernel_stack(status, scratch, cfg.mstatus_mprv, cfg.sp, cfg.tp, instr);
end
gen_signature_handshake(instr, CORE_STATUS, HANDLING_EXCEPTION);
instr = {instr,
// The trap is caused by an exception, read back xCAUSE, xEPC to see if these
// CSR values are set properly. The checking is done by comparing against the log
// generated by ISA simulator (spike).
$sformatf("csrr x%0d, 0x%0x # %0s", cfg.gpr[0], epc, epc.name()),
$sformatf("csrr x%0d, 0x%0x # %0s", cfg.gpr[0], cause, cause.name()),
// Breakpoint
$sformatf("li x%0d, 0x%0x # BREAKPOINT", cfg.gpr[1], BREAKPOINT),
$sformatf("beq x%0d, x%0d, ebreak_handler", cfg.gpr[0], cfg.gpr[1]),
// Check if it's an ECALL exception. Jump to ECALL exception handler
$sformatf("li x%0d, 0x%0x # ECALL_UMODE", cfg.gpr[1], ECALL_UMODE),
$sformatf("beq x%0d, x%0d, ecall_handler", cfg.gpr[0], cfg.gpr[1]),
$sformatf("li x%0d, 0x%0x # ECALL_SMODE", cfg.gpr[1], ECALL_SMODE),
$sformatf("beq x%0d, x%0d, ecall_handler", cfg.gpr[0], cfg.gpr[1]),
$sformatf("li x%0d, 0x%0x # ECALL_MMODE", cfg.gpr[1], ECALL_MMODE),
$sformatf("beq x%0d, x%0d, ecall_handler", cfg.gpr[0], cfg.gpr[1]),
// Page table fault or access fault conditions
$sformatf("li x%0d, 0x%0x", cfg.gpr[1], INSTRUCTION_ACCESS_FAULT),
$sformatf("beq x%0d, x%0d, instr_fault_handler", cfg.gpr[0], cfg.gpr[1]),
$sformatf("li x%0d, 0x%0x", cfg.gpr[1], LOAD_ACCESS_FAULT),
$sformatf("beq x%0d, x%0d, load_fault_handler", cfg.gpr[0], cfg.gpr[1]),
$sformatf("li x%0d, 0x%0x", cfg.gpr[1], STORE_AMO_ACCESS_FAULT),
$sformatf("beq x%0d, x%0d, store_fault_handler", cfg.gpr[0], cfg.gpr[1]),
$sformatf("li x%0d, 0x%0x", cfg.gpr[1], INSTRUCTION_PAGE_FAULT),
$sformatf("beq x%0d, x%0d, pt_fault_handler", cfg.gpr[0], cfg.gpr[1]),
$sformatf("li x%0d, 0x%0x", cfg.gpr[1], LOAD_PAGE_FAULT),
$sformatf("beq x%0d, x%0d, pt_fault_handler", cfg.gpr[0], cfg.gpr[1]),
$sformatf("li x%0d, 0x%0x", cfg.gpr[1], STORE_AMO_PAGE_FAULT),
$sformatf("beq x%0d, x%0d, pt_fault_handler", cfg.gpr[0], cfg.gpr[1]),
// Illegal instruction exception
$sformatf("li x%0d, 0x%0x # ILLEGAL_INSTRUCTION", cfg.gpr[1], ILLEGAL_INSTRUCTION),
$sformatf("beq x%0d, x%0d, illegal_instr_handler", cfg.gpr[0], cfg.gpr[1]),
// Skip checking tval for illegal instruction as it's implementation specific
$sformatf("csrr x%0d, 0x%0x # %0s", cfg.gpr[1], tval, tval.name()),
"1: jal x1, test_done "
};
gen_section($sformatf("%0smode_exception_handler", mode), instr);
endfunction
// Generate for interrupt vector table
virtual function void gen_interrupt_vector_table(string mode,
privileged_reg_t status,
privileged_reg_t cause,
privileged_reg_t ie,
privileged_reg_t ip,
privileged_reg_t scratch,
ref string instr[$]);
// In vector mode, the BASE address is shared between interrupt 0 and exception handling.
// When vectored interrupts are enabled, interrupt cause 0, which corresponds to user-mode
// software interrupts, are vectored to the same location as synchronous exceptions. This
// ambiguity does not arise in practice, since user-mode software interrupts are either
// disabled or delegated
instr = {instr, ".option norvc;",
$sformatf("j %0smode_exception_handler", mode)};
// Redirect the interrupt to the corresponding interrupt handler
for (int i = 1; i < max_interrupt_vector_num; i++) begin
instr.push_back($sformatf("j %0smode_intr_vector_%0d", mode, i));
end
if (!cfg.disable_compressed_instr) begin
instr = {instr, ".option rvc;"};
end
for (int i = 1; i < max_interrupt_vector_num; i++) begin
string intr_handler[$];
push_gpr_to_kernel_stack(status, scratch, cfg.mstatus_mprv, cfg.sp, cfg.tp, intr_handler);
gen_signature_handshake(.instr(intr_handler), .signature_type(CORE_STATUS), .core_status(HANDLING_IRQ));
intr_handler = {intr_handler,
$sformatf("csrr x%0d, 0x%0x # %0s", cfg.gpr[0], cause, cause.name()),
// Terminate the test if xCause[31] != 0 (indicating exception)
$sformatf("srli x%0d, x%0d, 0x%0x", cfg.gpr[0], cfg.gpr[0], XLEN-1),
$sformatf("beqz x%0d, 1f", cfg.gpr[0])};
gen_signature_handshake(.instr(intr_handler), .signature_type(WRITE_CSR), .csr(status));
gen_signature_handshake(.instr(intr_handler), .signature_type(WRITE_CSR), .csr(cause));
gen_signature_handshake(.instr(intr_handler), .signature_type(WRITE_CSR), .csr(ie));
gen_signature_handshake(.instr(intr_handler), .signature_type(WRITE_CSR), .csr(ip));
// Jump to commmon interrupt handling routine
intr_handler = {intr_handler,
$sformatf("j %0smode_intr_handler", mode),
"1: j test_done"};
gen_section($sformatf("%0smode_intr_vector_%0d", mode, i), intr_handler);
end
endfunction
// ECALL trap handler
// It does some clean up like dump GPRs before communicating with host to terminate the test.
// User can extend this function if some custom clean up routine is needed.
virtual function void gen_ecall_handler();
string str;
str = format_string("ecall_handler:", LABEL_STR_LEN);
instr_stream.push_back(str);
dump_perf_stats();
gen_register_dump();
str = format_string(" ", LABEL_STR_LEN);
str = {str, "j write_tohost"};
instr_stream.push_back(str);
endfunction
// Ebreak trap handler
// When breakpoint exception happens, epc will be written with ebreak instruction
// itself. Add epc by 4 and resume execution.
// Note the breakpoint could be triggered by a C.EBREAK instruction, the generated program
// guarantees that epc + 4 is a valid instruction boundary
// TODO: Support random operations in debug mode
// TODO: Support ebreak exception delegation
// TODO: handshake the correct Xcause CSR based on delegation privil. mode
virtual function void gen_ebreak_handler();
string instr[$];
gen_signature_handshake(instr, CORE_STATUS, EBREAK_EXCEPTION);
gen_signature_handshake(.instr(instr), .signature_type(WRITE_CSR), .csr(MCAUSE));
instr = {instr,
$sformatf("csrr x%0d, mepc", cfg.gpr[0]),
$sformatf("addi x%0d, x%0d, 4", cfg.gpr[0], cfg.gpr[0]),
$sformatf("csrw mepc, x%0d", cfg.gpr[0])
};
pop_gpr_from_kernel_stack(MSTATUS, MSCRATCH, cfg.mstatus_mprv, cfg.sp, cfg.tp, instr);
instr.push_back("mret");
gen_section("ebreak_handler", instr);
endfunction
// Illegal instruction handler
// Note: Save the illegal instruction to MTVAL is optional in the spec, and mepc could be
// a virtual address that cannot be used in machine mode handler. As a result, there's no way to
// know the illegal instruction is compressed or not. This hanlder just simply adds the PC by
// 4 and resumes execution. The way that the illegal instruction is injected guarantees that
// PC + 4 is a valid instruction boundary.
// TODO: handshake the corret Xcause CSR based on delegation setup
virtual function void gen_illegal_instr_handler();
string instr[$];
gen_signature_handshake(instr, CORE_STATUS, ILLEGAL_INSTR_EXCEPTION);
gen_signature_handshake(.instr(instr), .signature_type(WRITE_CSR), .csr(MCAUSE));
instr = {instr,
$sformatf("csrr x%0d, mepc", cfg.gpr[0]),
$sformatf("addi x%0d, x%0d, 4", cfg.gpr[0], cfg.gpr[0]),
$sformatf("csrw mepc, x%0d", cfg.gpr[0])
};
pop_gpr_from_kernel_stack(MSTATUS, MSCRATCH, cfg.mstatus_mprv, cfg.sp, cfg.tp, instr);
instr.push_back("mret");
gen_section("illegal_instr_handler", instr);
endfunction
// TODO: handshake correct csr based on delegation
virtual function void gen_instr_fault_handler();
string instr[$];
gen_signature_handshake(instr, CORE_STATUS, INSTR_FAULT_EXCEPTION);
gen_signature_handshake(.instr(instr), .signature_type(WRITE_CSR), .csr(MCAUSE));
pop_gpr_from_kernel_stack(MSTATUS, MSCRATCH, cfg.mstatus_mprv, cfg.sp, cfg.tp, instr);
instr.push_back("mret");
gen_section("instr_fault_handler", instr);
endfunction
// TODO: handshake correct csr based on delegation
virtual function void gen_load_fault_handler();
string instr[$];
gen_signature_handshake(instr, CORE_STATUS, LOAD_FAULT_EXCEPTION);
gen_signature_handshake(.instr(instr), .signature_type(WRITE_CSR), .csr(MCAUSE));
pop_gpr_from_kernel_stack(MSTATUS, MSCRATCH, cfg.mstatus_mprv, cfg.sp, cfg.tp, instr);
instr.push_back("mret");
gen_section("load_fault_handler", instr);
endfunction
// TODO: handshake correct csr based on delegation
virtual function void gen_store_fault_handler();
string instr[$];
gen_signature_handshake(instr, CORE_STATUS, STORE_FAULT_EXCEPTION);
gen_signature_handshake(.instr(instr), .signature_type(WRITE_CSR), .csr(MCAUSE));
pop_gpr_from_kernel_stack(MSTATUS, MSCRATCH, cfg.mstatus_mprv, cfg.sp, cfg.tp, instr);
instr.push_back("mret");
gen_section("store_fault_handler", instr);
endfunction
//---------------------------------------------------------------------------------------
// Page table setup
//---------------------------------------------------------------------------------------
// Create page table if virtual address translation is supported.
// The page is created based on the address translation mode - SV32, SV39, SV48
// Right now only the lowest level 4KB page table is configured as leaf page table entry (PTE),
// all the other super pages are link PTE.
virtual function void create_page_table();
string instr[];
if(cfg.virtual_addr_translation_on) begin
page_table_list = riscv_page_table_list#(SATP_MODE)::
type_id::create("page_table_list");
page_table_list.cfg = cfg;
page_table_list.create_page_table_list();
page_table_list.enable_exception = cfg.enable_page_table_exception;
`uvm_info(`gfn, $sformatf("Randomizing page tables, totally %0d page tables, mode = %0s",
page_table_list.page_table.size(), cfg.init_privileged_mode.name()), UVM_LOW)
page_table_list.privileged_mode = cfg.init_privileged_mode;
`DV_CHECK_RANDOMIZE_FATAL(page_table_list);
page_table_list.randomize_page_table();
`uvm_info(`gfn, "Finished creating page tables", UVM_LOW)
end
endfunction
// Generate the page table section of the program
// The page table is generated as a group of continuous 4KB data sections.
virtual function void gen_page_table_section();
string page_table_section[$];
if(page_table_list != null) begin
instr_stream.push_back(".pushsection .page_table,\"aw\",@progbits;");
foreach(page_table_list.page_table[i]) begin
page_table_list.page_table[i].gen_page_table_section(page_table_section);
instr_stream = {instr_stream, page_table_section};
end
instr_stream.push_back(".popsection;");
end
endfunction
// Only extend this function if the core utilizes a PLIC for handling interrupts
// In this case, the core will write to a specific location as the response to the interrupt, and
// external PLIC unit can detect this response and process the interrupt clean up accordingly.
virtual function void gen_plic_section(ref string interrupt_handler_instr[$]);
// Utilize the memory mapped handshake scheme to signal the testbench that the interrupt
// handling has been completed and we are about to xRET out of the handler
gen_signature_handshake(.instr(interrupt_handler_instr), .signature_type(CORE_STATUS),
.core_status(FINISHED_IRQ));
endfunction
// Interrupt handler routine
virtual function void gen_interrupt_handler_section(privileged_mode_t mode);
string mode_prefix;
string ls_unit;
privileged_reg_t status, ip, ie, scratch;
string interrupt_handler_instr[$];
ls_unit = (XLEN == 32) ? "w" : "d";
if(mode < cfg.init_privileged_mode) return;
case(mode)
MACHINE_MODE: begin
mode_prefix = "m";
status = MSTATUS;
ip = MIP;
ie = MIE;
scratch = MSCRATCH;
end
SUPERVISOR_MODE: begin
mode_prefix = "s";
status = SSTATUS;
ip = SIP;
ie = SIE;
scratch = SSCRATCH;
end
USER_MODE: begin
mode_prefix = "u";
status = USTATUS;
ip = UIP;
ie = UIE;
scratch = USCRATCH;
end
default: `uvm_fatal(get_full_name(), $sformatf("Unsupported mode: %0s", mode.name()))
endcase
// Read back interrupt related privileged CSR
// The value of these CSR are checked by comparing with spike simulation result.
interrupt_handler_instr = {
interrupt_handler_instr,
$sformatf("csrr x%0d, 0x%0x # %0s;", cfg.gpr[0], status, status.name()),
$sformatf("csrr x%0d, 0x%0x # %0s;", cfg.gpr[0], ie, ie.name()),
$sformatf("csrr x%0d, 0x%0x # %0s;", cfg.gpr[0], ip, ip.name()),
// Clean all the pending interrupt
$sformatf("csrrc x%0d, 0x%0x, x%0d # %0s;",
cfg.gpr[0], ip, cfg.gpr[0], ip.name())
};
gen_plic_section(interrupt_handler_instr);
// Restore user mode GPR value from kernel stack before return
pop_gpr_from_kernel_stack(status, scratch, cfg.mstatus_mprv,
cfg.sp, cfg.tp, interrupt_handler_instr);
interrupt_handler_instr = {interrupt_handler_instr,
$sformatf("%0sret;", mode_prefix)
};
// The interrupt handler will use one 4KB page
instr_stream.push_back(".align 12");
gen_section($sformatf("%0smode_intr_handler", mode_prefix), interrupt_handler_instr);
endfunction
//---------------------------------------------------------------------------------------
// Helper functions
//---------------------------------------------------------------------------------------
// Format a code section, without generating it
virtual function void format_section(ref string instr[$]);
string prefix = format_string(" ", LABEL_STR_LEN);
foreach(instr[i]) begin
instr[i] = {prefix, instr[i]};
end
endfunction
// Generate a code section
virtual function void gen_section(string label, string instr[$]);
string str;
if(label != "") begin
str = format_string($sformatf("%0s:", label), LABEL_STR_LEN);
instr_stream.push_back(str);
end
foreach(instr[i]) begin
str = {indent, instr[i]};
instr_stream.push_back(str);
end
instr_stream.push_back("");
endfunction
// Dump performance CSRs if applicable
virtual function void dump_perf_stats();
foreach(implemented_csr[i]) begin
if (implemented_csr[i] inside {[MCYCLE:MHPMCOUNTER31H]}) begin
gen_signature_handshake(.instr(instr_stream), .signature_type(WRITE_CSR), .csr(implemented_csr[i]));
end
end
endfunction
// Write the generated program to a file
function void gen_test_file(string test_name);
int fd;
fd = $fopen(test_name,"w");
foreach(instr_stream[i]) begin
$fwrite(fd, {instr_stream[i],"\n"});
end
$fclose(fd);
`uvm_info(get_full_name(), $sformatf("%0s is generated", test_name), UVM_LOW)
endfunction
// Helper function to generate the proper sequence of handshake instructions
// to signal the testbench (see riscv_signature_pkg.sv)
function void gen_signature_handshake(ref string instr[$],
input signature_type_t signature_type,
core_status_t core_status = INITIALIZED,
test_result_t test_result = TEST_FAIL,
privileged_reg_t csr = MSCRATCH,
string addr_label = "");
if (cfg.require_signature_addr) begin
string str[$];
str = {$sformatf("li x%0d, 0x%0h", cfg.gpr[1], cfg.signature_addr)};
instr = {instr, str};
case (signature_type)
// A single data word is written to the signature address.
// Bits [7:0] contain the signature_type of CORE_STATUS, and the upper
// XLEN-8 bits contain the core_status_t data.
CORE_STATUS: begin
str = {$sformatf("li x%0d, 0x%0h", cfg.gpr[0], core_status),
$sformatf("slli x%0d, x%0d, 8", cfg.gpr[0], cfg.gpr[0]),
$sformatf("addi x%0d, x%0d, 0x%0h", cfg.gpr[0],
cfg.gpr[0], signature_type),
$sformatf("sw x%0d, 0(x%0d)", cfg.gpr[0], cfg.gpr[1])};
instr = {instr, str};
end
// A single data word is written to the signature address.
// Bits [7:0] contain the signature_type of TEST_RESULT, and the upper
// XLEN-8 bits contain the test_result_t data.
TEST_RESULT: begin
str = {$sformatf("li x%0d, 0x%0h", cfg.gpr[0], test_result),
$sformatf("slli x%0d, x%0d, 8", cfg.gpr[0], cfg.gpr[0]),
$sformatf("addi x%0d, x%0d, 0x%0h", cfg.gpr[0],
cfg.gpr[0], signature_type),
$sformatf("sw x%0d, 0(x%0d)", cfg.gpr[0], cfg.gpr[1])};
instr = {instr, str};
end
// The first write to the signature address contains just the
// signature_type of WRITE_GPR.
// It is followed by 32 consecutive writes to the signature address,
// each writing the data contained in one GPR, starting from x0 as the
// first write, and ending with x31 as the 32nd write.
WRITE_GPR: begin
str = {$sformatf("li x%0d, 0x%0h", cfg.gpr[0], signature_type),
$sformatf("sw x%0d, 0(x%0d)", cfg.gpr[0], cfg.gpr[1])};
instr = {instr, str};
for(int i = 0; i < 32; i++) begin
str = {$sformatf("sw x%0x, 0(x%0d)", i, cfg.gpr[1])};
instr = {instr, str};
end
end
// The first write to the signature address contains the
// signature_type of WRITE_CSR in bits [7:0], and the CSR address in
// the upper XLEN-8 bits.
// It is followed by a second write to the signature address,
// containing the data stored in the specified CSR.
WRITE_CSR: begin
str = {$sformatf("li x%0d, 0x%0h", cfg.gpr[0], csr),
$sformatf("slli x%0d, x%0d, 8", cfg.gpr[0], cfg.gpr[0]),
$sformatf("addi x%0d, x%0d, 0x%0h", cfg.gpr[0],
cfg.gpr[0], signature_type),
$sformatf("sw x%0d, 0(x%0d)", cfg.gpr[0], cfg.gpr[1]),
$sformatf("csrr x%0d, 0x%0h", cfg.gpr[0], csr),
$sformatf("sw x%0d, 0(x%0d)", cfg.gpr[0], cfg.gpr[1])};
instr = {instr, str};
end
default: begin
`uvm_fatal(`gfn, "signature_type is not defined")
end
endcase
end
endfunction
//---------------------------------------------------------------------------------------
// Inject directed instruction stream
//---------------------------------------------------------------------------------------
virtual function void add_directed_instr_stream(string name, int unsigned ratio);
directed_instr_stream_ratio[name] = ratio;
`uvm_info(`gfn, $sformatf("Adding directed instruction stream:%0s ratio:%0d/1000", name, ratio), UVM_LOW)
endfunction
virtual function void get_directed_instr_stream();
string args, val;
string stream_name_opts, stream_freq_opts;
string stream_name;
int stream_freq;
string opts[$];
for (int i=0; i<cfg.max_directed_instr_stream_seq; i++) begin
args = $sformatf("directed_instr_%0d=", i);
stream_name_opts = $sformatf("stream_name_%0d=", i);
stream_freq_opts = $sformatf("stream_freq_%0d=", i);
if ($value$plusargs({args,"%0s"}, val)) begin
uvm_split_string(val, ",", opts);
if (opts.size() != 2) begin
`uvm_fatal(`gfn, $sformatf(
"Incorrect directed instruction format : %0s, expect: name,ratio", val))
end else begin
add_directed_instr_stream(opts[0], opts[1].atoi());
end
end else if ($value$plusargs({stream_name_opts,"%0s"}, stream_name) &&
$value$plusargs({stream_freq_opts,"%0d"}, stream_freq)) begin
add_directed_instr_stream(stream_name, stream_freq);
end
end
endfunction
// Generate directed instruction stream based on the ratio setting
virtual function void generate_directed_instr_stream(input string label,
input int unsigned original_instr_cnt,
input int unsigned min_insert_cnt = 0,
input bit kernel_mode = 0,
output riscv_instr_stream instr_stream[]);
uvm_object object_h;
riscv_rand_instr_stream new_instr_stream;
int unsigned instr_insert_cnt;
int unsigned idx;
uvm_coreservice_t coreservice = uvm_coreservice_t::get();
uvm_factory factory = coreservice.get_factory();
if(cfg.no_directed_instr) return;
foreach(directed_instr_stream_ratio[instr_stream_name]) begin
instr_insert_cnt = original_instr_cnt * directed_instr_stream_ratio[instr_stream_name] / 1000;
if(instr_insert_cnt <= min_insert_cnt) begin
instr_insert_cnt = min_insert_cnt;
end
`ifdef DSIM
// Temporarily skip loop instruction for dsim as it cannot support dynamic array
// randomization
if (uvm_is_match("*loop*", instr_stream_name)) begin
`uvm_info(`gfn, $sformatf("%0s is skipped", instr_stream_name), UVM_LOW)
continue;
end
`endif
`uvm_info(get_full_name(), $sformatf("Insert directed instr stream %0s %0d/%0d times",
instr_stream_name, instr_insert_cnt, original_instr_cnt), UVM_LOW)
for(int i = 0; i < instr_insert_cnt; i++) begin
string name = $sformatf("%0s_%0d", instr_stream_name, i);
object_h = factory.create_object_by_name(instr_stream_name, get_full_name(), name);
if(object_h == null) begin
`uvm_fatal(get_full_name(), $sformatf("Cannot create instr stream %0s", name))
end
if($cast(new_instr_stream, object_h)) begin
new_instr_stream.cfg = cfg;
new_instr_stream.label = $sformatf("%0s_%0d", label, idx);
new_instr_stream.kernel_mode = kernel_mode;
`DV_CHECK_RANDOMIZE_FATAL(new_instr_stream)
instr_stream = {instr_stream, new_instr_stream};
end else begin
`uvm_fatal(get_full_name(), $sformatf("Cannot cast instr stream %0s", name))
end
idx++;
end
end
instr_stream.shuffle();
endfunction
//---------------------------------------------------------------------------------------
// Generate the debug rom, and any related programs
// TODO - refactor such that debug_rom is generated by a separate class
//---------------------------------------------------------------------------------------
// Generate the program in the debug ROM
// Processor will fetch instruction from here upon receiving debug request from debug module
virtual function void gen_debug_rom();
string instr[$];
string debug_end[$];
string dret;
string debug_sub_program_name[$] = {};
string str[$];
if (riscv_instr_pkg::support_debug_mode) begin
dret = {format_string(" ", LABEL_STR_LEN), "dret"};
// The main debug rom
if (!cfg.gen_debug_section) begin
// If the debug section should not be generated, we just populate it
// with a dret instruction.
instr = {dret};
gen_section("debug_rom", instr);
end else begin
if (cfg.enable_ebreak_in_debug_rom) begin
// As execution of ebreak in D mode causes core to
// re-enter D mode, this directed sequence will be a loop that ensures the
// ebreak instruction will only be executed once to prevent infinitely
// looping back to the beginning of the debug rom.
// Write dscratch to random GPR and branch to debug_end if greater
// than 0, for ebreak loops.
// Use dscratch1 to store original GPR value.
str = {$sformatf("csrw 0x%0x, x%0d", DSCRATCH1, cfg.scratch_reg),
$sformatf("csrr x%0d, 0x%0x", cfg.scratch_reg, DSCRATCH0),
$sformatf("beq x%0d, x0, 1f", cfg.scratch_reg),
$sformatf("j debug_end"),
$sformatf("1: csrr x%0d, 0x%0x", cfg.scratch_reg, DSCRATCH1)};
instr = {instr, str};
end
// Need to save off GPRs to avoid modifying program flow
push_gpr_to_kernel_stack(MSTATUS, MSCRATCH, cfg.mstatus_mprv, cfg.sp, cfg.tp, instr);
// Signal that the core entered debug rom only if the rom is actually
// being filled with random instructions to prevent stress tests from
// having to execute unnecessary push/pop of GPRs on the stack ever
// time a debug request is sent
gen_signature_handshake(instr, CORE_STATUS, IN_DEBUG_MODE);
if (cfg.enable_ebreak_in_debug_rom) begin
// send dpc and dcsr to testbench, as this handshake will be
// executed twice due to the ebreak loop, there should be no change
// in their values as by the Debug Mode Spec Ch. 4.1.8
gen_signature_handshake(.instr(instr), .signature_type(WRITE_CSR), .csr(DCSR));
gen_signature_handshake(.instr(instr), .signature_type(WRITE_CSR), .csr(DPC));
end
if (cfg.set_dcsr_ebreak) begin
// We want to set dcsr.ebreak(m/s/u) to 1'b1, depending on what modes
// are available.
// TODO(udinator) - randomize the dcsr.ebreak setup
gen_dcsr_ebreak(instr);
end
if (cfg.enable_debug_single_step) begin
// To enable debug single stepping, we must set dcsr.step to 1.
// We will repeat the debug single stepping process a random number
// of times, using a dscratch CSR as the counter, and decrement
// this counter by 1 every time we enter debug mode, until this
// counter reaches 0, at which point we set dcsr.step to 0 until
// the next debug stimulus is asserted.
// Store our designated scratch_reg to dscratch1
str = {$sformatf("csrw 0x%0x, x%0d", DSCRATCH1, cfg.scratch_reg),
// Only un-set dcsr.step if it is 1 and the iterations counter
// is at 0 (has finished iterating)
$sformatf("csrr x%0d, 0x%0x", cfg.scratch_reg, DCSR),
$sformatf("andi x%0d, x%0d, 4", cfg.scratch_reg, cfg.scratch_reg),
// If dcsr.step is 0, set to 1 and set the counter
$sformatf("beqz x%0d, 1f", cfg.scratch_reg),
$sformatf("csrr x%0d, 0x%0x", cfg.scratch_reg, DSCRATCH0),
// if the counter is greater than 0, decrement and continue single stepping
$sformatf("bgtz x%0d, 2f", cfg.scratch_reg),
$sformatf("csrc 0x%0x, 0x4", DCSR),
$sformatf("beqz x0, 3f"),
// Set dcsr.step and the num_iterations counter
$sformatf("1: csrs 0x%0x, 0x4", DCSR),
$sformatf("li x%0d, %0d", cfg.scratch_reg, cfg.single_step_iterations),
$sformatf("csrw 0x%0x, x%0d", DSCRATCH0, cfg.scratch_reg),
$sformatf("beqz x0, 3f"),
// Decrement dscratch counter
$sformatf("2: csrr x%0d, 0x%0x", cfg.scratch_reg, DSCRATCH0),
$sformatf("addi x%0d, x%0d, -1", cfg.scratch_reg, cfg.scratch_reg),
$sformatf("csrw 0x%0x, x%0d", DSCRATCH0, cfg.scratch_reg),
// Restore scratch_reg value from dscratch1
$sformatf("3: csrr x%0d, 0x%0x", cfg.scratch_reg, DSCRATCH1)
};
instr = {instr, str};
// write dpc to testbench
gen_signature_handshake(.instr(instr), .signature_type(WRITE_CSR), .csr(DPC));
// write out the counter to the testbench
gen_signature_handshake(.instr(instr), .signature_type(WRITE_CSR), .csr(DSCRATCH0));
end
// Check dcsr.cause, and update dpc by 0x4 if the cause is ebreak, as
// ebreak will set set dpc to its own address, which will cause an
// infinite loop.
str = {$sformatf("csrr x%0d, 0x%0x", cfg.scratch_reg, DCSR),
$sformatf("slli x%0d, x%0d, 0x17", cfg.scratch_reg, cfg.scratch_reg),
$sformatf("srli x%0d, x%0d, 0x1d", cfg.scratch_reg, cfg.scratch_reg),
$sformatf("li x%0d, 0x1", cfg.gpr[0]),
$sformatf("bne x%0d, x%0d, 4f", cfg.scratch_reg, cfg.gpr[0])};
instr = {instr, str};
increment_csr(DPC, 4, instr);
str = {"4: nop"};
instr = {instr, str};
// write DCSR to the testbench for any analysis
gen_signature_handshake(.instr(instr), .signature_type(WRITE_CSR), .csr(DCSR));
// Increment dscratch0 by 1 to update the loop counter for all ebreak
// tests
if (cfg.enable_ebreak_in_debug_rom || cfg.set_dcsr_ebreak) begin
// Add 1 to dscratch0
increment_csr(DSCRATCH0, 1, instr);
str = {$sformatf("csrr x%0d, 0x%0x", cfg.scratch_reg, DSCRATCH1)};
instr = {instr, str};
end
format_section(instr);
gen_sub_program(debug_sub_program, debug_sub_program_name,
cfg.num_debug_sub_program, 1'b1, "debug_sub");
debug_program = riscv_instr_sequence::type_id::create("debug_program");
debug_program.instr_cnt = cfg.debug_program_instr_cnt;
debug_program.is_debug_program = 1;
debug_program.cfg = cfg;
`DV_CHECK_RANDOMIZE_FATAL(debug_program)
debug_program.gen_instr(.is_main_program(1'b1), .no_branch(cfg.no_branch_jump));
gen_callstack(debug_program, debug_sub_program, debug_sub_program_name,
cfg.num_debug_sub_program);
debug_program.post_process_instr();
debug_program.generate_instr_stream(.no_label(1'b1));
insert_sub_program(debug_sub_program, instr_stream);
instr = {instr, debug_program.instr_string_list};
gen_section("debug_rom", instr);
// Set dscratch0 back to 0x0 to prepare for the next entry into debug
// mode, and write dscratch0 and dcsr to the testbench for any
// analysis
if (cfg.enable_ebreak_in_debug_rom) begin
// send dpc and dcsr to testbench, as this handshake will be
// executed twice due to the ebreak loop, there should be no change
// in their values as by the Debug Mode Spec Ch. 4.1.8
gen_signature_handshake(.instr(debug_end), .signature_type(WRITE_CSR), .csr(DCSR));
gen_signature_handshake(.instr(debug_end), .signature_type(WRITE_CSR), .csr(DPC));
str = {$sformatf("csrwi 0x%0x, 0x0", DSCRATCH0)};
debug_end = {debug_end, str};
end
pop_gpr_from_kernel_stack(MSTATUS, MSCRATCH, cfg.mstatus_mprv,
cfg.sp, cfg.tp, debug_end);
// We have been using dscratch1 to store the
// value of our given scratch register for use in ebreak loop, so we
// need to restore its value before returning from D mode
if (cfg.enable_ebreak_in_debug_rom) begin
str = {$sformatf("csrr x%0d, 0x%0x", cfg.scratch_reg, DSCRATCH1)};
debug_end = {debug_end, str};
end
format_section(debug_end);
debug_end = {debug_end, dret};
gen_section("debug_end", debug_end);
end
end
endfunction
// Generate exception handling routine for debug ROM
virtual function void gen_debug_exception_handler();
if (riscv_instr_pkg::support_debug_mode) begin
string instr[];
instr = {"dret"};
gen_section("debug_exception", instr);
end
endfunction
// Set dcsr.ebreak(m/s/u)
// TODO(udinator) - randomize the setup for these fields
virtual function void gen_dcsr_ebreak(ref string instr[$]);
string str;
if (MACHINE_MODE inside {riscv_instr_pkg::supported_privileged_mode}) begin
str = $sformatf("li x%0d, 0x8000", cfg.scratch_reg);
instr.push_back(str);
str = $sformatf("csrs dcsr, x%0d", cfg.scratch_reg);
instr.push_back(str);
end
if (SUPERVISOR_MODE inside {riscv_instr_pkg::supported_privileged_mode}) begin
str = $sformatf("li x%0d, 0x2000", cfg.scratch_reg);
instr.push_back(str);
str = $sformatf("csrs dcsr, x%0d", cfg.scratch_reg);
instr.push_back(str);
end
if (USER_MODE inside {riscv_instr_pkg::supported_privileged_mode}) begin
str = $sformatf("li x%0d, 0x1000", cfg.scratch_reg);
instr.push_back(str);
str = $sformatf("csrs dcsr, x%0d", cfg.scratch_reg);
instr.push_back(str);
end
endfunction
virtual function void increment_csr(privileged_reg_t csr, int val, ref string instr[$]);
string str;
str = $sformatf("csrr x%0d, 0x%0x", cfg.scratch_reg, csr);
instr.push_back(str);
str = $sformatf("addi x%0d, x%0d, 0x%0x", cfg.scratch_reg, cfg.scratch_reg, val);
instr.push_back(str);
str = $sformatf("csrw 0x%0x, x%0d", csr, cfg.scratch_reg);
instr.push_back(str);
endfunction
endclass