Introduce ENABLE_USE_ELF

Currently, the system test suite is compiled into a single ELF
executable, leading to discrepancies between the inputs for Linux
kernel emulation and the system test suite. By introducing
ENABLE_USE_ELF, we can allow the use of the ELF executable when
running the system test suite.

This might be a temporarily solution, need to refactor more.

.github/workflows/main.yml

@@ -67,11 +67,11 @@ jobs:
     - name: misalignment test in block emulation
       run: |
             make -C tests/system/alignment/
-            make distclean && make ENABLE_EXT_C=0 ENABLE_SYSTEM=1 misalign-in-blk-emu -j$(nproc)
+            make distclean && make ENABLE_USE_ELF=1 ENABLE_EXT_C=0 ENABLE_SYSTEM=1 misalign-in-blk-emu -j$(nproc)
     - name: MMU test
       run: |
             make -C tests/system/mmu/
-            make distclean && make ENABLE_SYSTEM=1 mmu-test -j$(nproc)
+            make distclean && make ENABLE_USE_ELF=1 ENABLE_SYSTEM=1 mmu-test -j$(nproc)
     - name: gdbstub test
       run: |
             make distclean && make ENABLE_GDBSTUB=1 gdbstub-test -j$(nproc)

Makefile

@@ -15,7 +15,10 @@ CFLAGS += -include src/common.h
 # However, the Linux kernel emulation includes the Image, DT, and
 # root filesystem (rootfs). Therefore, the test suite needs this
 # flag to load the ELF and differentiate it from the kernel emulation.
-USE_ELF ?= 0
+ENABLE_USE_ELF ?= 0
+ifeq ($(call has, USE_ELF), 1)
+DEFINE_USE_ELF := -DUSE_ELF
+endif
 
 ENABLE_SYSTEM ?= 0
 $(call set-feature, SYSTEM)
@@ -248,7 +251,7 @@ endif
 
 $(OUT)/%.o: src/%.c $(deps_emcc)
 	$(VECHO) "  CC\t$@\n"
-	$(Q)$(CC) -o $@ $(CFLAGS) $(CFLAGS_emcc) -c -MMD -MF $@.d $<
+	$(Q)$(CC) $(DEFINE_USE_ELF) -o $@ $(CFLAGS) $(CFLAGS_emcc) -c -MMD -MF $@.d $<
 
 $(BIN): $(OBJS) $(DEV_OBJS)
 	$(VECHO) "  LD\t$@\n"

src/main.c

@@ -209,30 +209,34 @@ int main(int argc, char **args)
     run_flag |= opt_prof_data << 2;
 
     vm_attr_t attr = {
+#if RV32_HAS(SYSTEM) && !defined(USE_ELF)
         .mem_size = 512 * 1024 * 1024, /* FIXME: variadic size */
+#else
+        .mem_size = MEM_SIZE, /* FIXME: variadic size */
+#endif
         .stack_size = STACK_SIZE,
         .args_offset_size = ARGS_OFFSET_SIZE,
         .argc = prog_argc,
         .argv = prog_args,
         .log_level = 0,
         .run_flag = run_flag,
         .profile_output_file = prof_out_file,
-#if RV32_HAS(SYSTEM)
+#if RV32_HAS(SYSTEM) && !defined(USE_ELF)
         .data.system = malloc(sizeof(vm_system_t)),
 #else
         .data.user = malloc(sizeof(vm_user_t)),
 #endif
         .cycle_per_step = CYCLE_PER_STEP,
         .allow_misalign = opt_misaligned,
     };
-#if defined(USE_ELF)
+#if RV32_HAS(SYSTEM) && !defined(USE_ELF)
+    assert(attr.data.system);
+    attr.data.system->kernel = "build/Image";       /* FIXME: hardcoded */
+    attr.data.system->initrd = "build/rootfs.cpio"; /* FIXME: hardcoded */
+    attr.data.system->dtb = "build/minimal.dtb";    /* FIXME: hardcoded */
+#else
     assert(attr.data.user);
     attr.data.user->elf_program = opt_prog_name;
-#elif RV32_HAS(SYSTEM)
-    assert(attr.data.system);
-    attr.data.system->kernel = "build/Image"; /* FIXME: hardcoded */
-    attr.data.system->initrd = "build/rootfs.cpio";/* FIXME: hardcoded */
-    attr.data.system->dtb = "build/minimal.dtb";/* FIXME: hardcoded */
 #endif
 
     /* create the RISC-V runtime */

src/riscv.c

@@ -307,6 +307,8 @@ riscv_t *rv_create(riscv_user_t rv_attr)
         elf_delete(elf);
 
 #if RV32_HAS(SYSTEM)
+        /* this variable has external linkage to mmu_io defined in system.c */
+        extern riscv_io_t mmu_io;
         /* install the MMU I/O handlers */
         memcpy(&rv->io, &mmu_io, sizeof(riscv_io_t));
 #else
@@ -333,7 +335,7 @@ riscv_t *rv_create(riscv_user_t rv_attr)
         memcpy(&rv->io, &io, sizeof(riscv_io_t));
 #endif /* RV32_HAS(SYSTEM) */
     }
-#if RV32_HAS(SYSTEM) && !defined(USE_ELF)
+#if RV32_HAS(SYSTEM)
     else {
         /* *-----------------------------------------*
          * |              Memory layout              |
@@ -464,7 +466,7 @@ void rv_run(riscv_t *rv)
 
     vm_attr_t *attr = PRIV(rv);
     assert(attr &&
-#if RV32_HAS(SYSTEM)
+#if RV32_HAS(SYSTEM) && !defined(USE_ELF)
            attr->data.system && attr->data.system->kernel &&
            attr->data.system->initrd && attr->data.system->dtb
 #else