diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f55824e..5b77088 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -20,9 +20,23 @@ variables:
      GIT_SUBMODULE_STRATEGY: recursive
 
 stages:          # List of stages for jobs, and their order of execution
+  - toolchain
   - build
 
-build-fpga:       # This job runs in the build stage, which runs first.
+build toolchain:
+  tags:
+    - linux
+  stage: toolchain
+  script:
+    - source init_env.sh
+    - cd sw/cc65
+    - make -j
+  artifacts:
+    paths:
+      - sw/cc65/bin
+      - sw/cc65/lib
+
+build fpga:       # This job runs in the build stage, which runs first.
   tags:
     - efinity
     - linux
@@ -32,15 +46,36 @@ build-fpga:       # This job runs in the build stage, which runs first.
     - cd hw/efinix_fpga
     - make
 
-build-sim:
+build sim:
   tags:
    - iverilog
    - linux
   stage: build
   script:  
     - source init_env.sh
-    - cd sw/cc65
-    - make -j
-    - cd ../..
     - cd hw/efinix_fpga/simulation
     - make
+  dependencies:
+    - build toolchain
+
+build bios:
+  tags:
+    - linux
+  stage: build
+  script:
+    - source init_env.sh
+    - cd sw/
+    - make bios
+  dependencies:
+    - build toolchain
+
+build kernel:
+  tags:
+    - linux
+  stage: build
+  script:
+    - source init_env.sh
+    - cd sw/
+    - make kernel
+  dependencies:
+    - build toolchain
\ No newline at end of file
diff --git a/.gitmodules b/.gitmodules
index 0a0a7e3..da7e628 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -4,3 +4,6 @@
 [submodule "hw/efinix_fpga/simulation/src/verilog-6502"]
 	path = hw/efinix_fpga/simulation/src/verilog-6502
 	url = https://git.byronlathi.com/bslathi19/verilog-6502
+[submodule "hw/efinix_fpga/simulation/src/verilog-sd-emulator"]
+	path = hw/efinix_fpga/simulation/src/verilog-sd-emulator
+	url = https://git.byronlathi.com/bslathi19/verilog-sd-emulator
diff --git a/hw/efinix_fpga/simulation/src/verilog-sd-emulator b/hw/efinix_fpga/simulation/src/verilog-sd-emulator
new file mode 160000
index 0000000..7fb88c9
--- /dev/null
+++ b/hw/efinix_fpga/simulation/src/verilog-sd-emulator
@@ -0,0 +1 @@
+Subproject commit 7fb88c9ee1ca65dd5bfd10b2e0f6331e958abdd7
diff --git a/sw/Makefile b/sw/Makefile
index c379713..a47ed42 100644
--- a/sw/Makefile
+++ b/sw/Makefile
@@ -1,6 +1,6 @@
-.PHONY: all install bootloader kernel clean
+.PHONY: all install bios kernel clean
 
-all: toolchain bootloader kernel
+all: toolchain bios kernel
 
 install: all
 	sh script/format_disk.sh
@@ -9,8 +9,8 @@ install: all
 toolchain:
 	@$(MAKE) -j4 -C cc65
 
-bootloader:
-	@$(MAKE) -C bootloader
+bios:
+	@$(MAKE) -C bios
 
 kernel:
 	@$(MAKE) -C kernel