thumb: add execution of instructions

also arm: fix some instructions

Signed-off-by: Amneesh Singh <natto@weirdnatto.in>

tests/cpu/arm/exec.cc

@@ -1,9 +1,7 @@
+#include "cpu/cpu-fixture.hh"
 #include "cpu/cpu-impl.hh"
-#include "fixture.hh"
 #include "util/bits.hh"
 #include <catch2/catch_test_macros.hpp>
-#include <limits>
-#include <variant>
 
 using namespace matar;
 
@@ -14,11 +12,11 @@ using namespace arm;
 TEST_CASE_METHOD(CpuFixture, "Branch and Exchange", TAG) {
     InstructionData data = BranchAndExchange{ .rn = 3 };
 
-    setr(3, 342890);
+    setr(3, 342800);
 
     exec(data);
 
-    CHECK(getr(15) == 342890);
+    CHECK(getr(15) == 342800);
 }
 
 TEST_CASE_METHOD(CpuFixture, "Branch", TAG) {
@@ -806,14 +804,11 @@ TEST_CASE_METHOD(CpuFixture, "Data Processing", TAG) {
 
         processing->opcode = OpCode::AND;
 
-        cpsr.set_z(false);
-        set_psr(cpsr);
         exec(data, Condition::EQ);
 
         // condition is false
         CHECK(getr(5) == 0);
 
-        cpsr = psr();
         cpsr.set_z(true);
         set_psr(cpsr);
         exec(data, Condition::EQ);

tests/cpu/arm/fixture.cc

@@ -1,96 +0,0 @@
-#include "fixture.hh"
-
-Psr
-CpuFixture::psr(bool spsr) {
-    Psr psr(0);
-    CpuImpl tmp = cpu;
-    arm::Instruction instruction(
-      Condition::AL,
-      arm::PsrTransfer{ .operand = 0,
-                        .spsr    = spsr,
-                        .type    = arm::PsrTransfer::Type::Mrs,
-                        .imm     = false });
-
-    instruction.exec(tmp);
-
-    psr.set_all(getr_(0, tmp));
-    return psr;
-}
-
-void
-CpuFixture::set_psr(Psr psr, bool spsr) {
-    // R0
-    uint32_t old = getr(0);
-
-    setr(0, psr.raw());
-
-    arm::Instruction instruction(
-      Condition::AL,
-      arm::PsrTransfer{ .operand = 0,
-                        .spsr    = spsr,
-                        .type    = arm::PsrTransfer::Type::Msr,
-                        .imm     = false });
-
-    instruction.exec(cpu);
-
-    setr(0, old);
-}
-
-// We need these workarounds to just use the public API and not private
-// fields. Assuming that these work correctly is necessary. Besides, all it
-// matters is that the public API is correct.
-uint32_t
-CpuFixture::getr_(uint8_t r, CpuImpl& cpu) {
-    size_t addr   = 13000;
-    size_t offset = r == 15 ? 4 : 0;
-    uint32_t word = bus.read_word(addr + offset);
-    CpuImpl tmp   = cpu;
-    uint32_t ret  = 0xFFFFFFFF;
-    uint8_t base  = r ? 0 : 1;
-
-    // set R0/R1 = 0
-    arm::Instruction zero(
-      Condition::AL,
-      arm::DataProcessing{ .operand = 0u,
-                           .rd      = base,
-                           .rn      = 0,
-                           .set     = false,
-                           .opcode  = arm::DataProcessing::OpCode::MOV });
-
-    // get register
-    arm::Instruction get(
-      Condition::AL,
-      arm::SingleDataTransfer{ .offset = static_cast<uint16_t>(addr),
-                               .rd     = r,
-                               .rn     = base,
-                               .load   = false,
-                               .write  = false,
-                               .byte   = false,
-                               .up     = true,
-                               .pre    = true });
-
-    zero.exec(tmp);
-    get.exec(tmp);
-
-    addr += offset;
-
-    ret = bus.read_word(addr);
-
-    bus.write_word(addr, word);
-
-    return ret;
-}
-
-void
-CpuFixture::setr_(uint8_t r, uint32_t value, CpuImpl& cpu) {
-    // set register
-    arm::Instruction set(
-      Condition::AL,
-      arm::DataProcessing{ .operand = value,
-                           .rd      = r,
-                           .rn      = 0,
-                           .set     = false,
-                           .opcode  = arm::DataProcessing::OpCode::MOV });
-
-    set.exec(cpu);
-}

tests/cpu/arm/fixture.hh

@@ -1,37 +0,0 @@
-#include "cpu/cpu-impl.hh"
-
-using namespace matar;
-
-class CpuFixture {
-  public:
-    CpuFixture()
-      : bus(Memory(std::array<uint8_t, Memory::BIOS_SIZE>(),
-                   std::vector<uint8_t>(Header::HEADER_SIZE)))
-      , cpu(bus) {}
-
-  protected:
-    void exec(arm::InstructionData data, Condition condition = Condition::AL) {
-        arm::Instruction instruction(condition, data);
-        instruction.exec(cpu);
-    }
-
-    void reset(uint32_t value = 0) { setr(15, value + 8); }
-
-    uint32_t getr(uint8_t r) { return getr_(r, cpu); }
-
-    void setr(uint8_t r, uint32_t value) { setr_(r, value, cpu); }
-
-    Psr psr(bool spsr = false);
-
-    void set_psr(Psr psr, bool spsr = false);
-
-    Bus bus;
-    CpuImpl cpu;
-
-  private:
-    // hack to get a register
-    uint32_t getr_(uint8_t r, CpuImpl& cpu);
-
-    // hack to set a register
-    void setr_(uint8_t r, uint32_t value, CpuImpl& cpu);
-};

tests/cpu/arm/meson.build

@@ -1,5 +1,4 @@
 tests_sources += files(
-  'fixture.cc',
   'instruction.cc',
   'exec.cc'
 )