Serial queue (#51)

* Update mmio.h to match serial queue renaming sharedringbuffer.h has been renamed queue.h Signed-off-by: Peter Chubb <[email protected]> * Update for sDDF serial queue renaming Everywhere rename ring->queue, used->active Signed-off-by: Peter Chubb <[email protected]> * Updated submodule sDDF to head, to get queue renaming changes Signed-off-by: Peter Chubb <[email protected]> * Make the Makefile use the sDDF submodule Signed-off-by: Peter Chubb <[email protected]> * More virtio example fixes Rename MUX->Virtualiser, ring->queue Fix Makefile to track dependencies properly, Fix printf.c name clash (the uart driver wants the sddf version, vmm.o wants the libvmm version Signed-off-by: Peter Chubb <[email protected]> --------- Signed-off-by: Peter Chubb <[email protected]> Signed-off-by: Peter Chubb <[email protected]>
au-ts · Mar 19, 2024 · d05b03d · d05b03d
1 parent 73c142d
commit d05b03d
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Showing 9 changed files with 118 additions and 121 deletions.
diff --git a/examples/virtio/Makefile b/examples/virtio/Makefile
@@ -66,13 +66,12 @@ DTS := $(IMAGE_DIR)/linux.dts
 DTB := $(BUILD_DIR)/linux.dtb
 INITRD := $(IMAGE_DIR)/rootfs.cpio.gz
 
-SDDF := sddf
-SDDF_SERIAL_RINGBUFFER := $(SDDF)/serial/libserialsharedringbuffer
+SDDF ?= sddf
 SDDF_SERIAL_COMPONENTS := $(SDDF)/serial/components
 SDDF_SERIAL_DRIVER := $(SDDF)/drivers/serial/arm
 SDDF_UTIL := $(SDDF)/util
 
-ELFS := vmm.elf serial_mux_tx.elf serial_mux_rx.elf uart_driver.elf
+ELFS := vmm.elf serial_virt_tx.elf serial_virt_rx.elf uart_driver.elf
 
 IMAGE_FILE = $(BUILD_DIR)/loader.img
 REPORT_FILE = $(BUILD_DIR)/report.txt
@@ -94,14 +93,18 @@ VMM_OBJS := vmm.o \
 			vcpu.o \
 			mmio.o \
 			console.o \
-			virtio.o \
-			shared_ringbuffer.o
+			virtio.o
 
-SERIAL_MUX_TX_OBJS := mux_tx.o shared_ringbuffer.o
-SERIAL_MUX_RX_OBJS := mux_rx.o shared_ringbuffer.o
-SERIAL_DRIVER_OBJS := uart.o shared_ringbuffer.o
+SERIAL_VIRT_TX_OBJS := virt_tx.o
+SERIAL_VIRT_RX_OBJS := virt_rx.o
+SERIAL_DRIVER_OBJS := uart.o sddf_printf.o putchar_debug.o
+
+ALL_OBJS := $(addprefix ${BUILD_DIR}/,${VMM_OBJS} ${SERIAL_VIRT_TX_OBJS} ${SERIAL_VIRT_RX_OBJS} ${SERIAL_DRIVER_OBJS})
+
+DEPENDS := ${ALL_OBJS:.o=.d}
 
 # Toolchain flags
+
 # FIXME: For optimisation we should consider providing the flag -mcpu.
 # FIXME: We should also consider whether -mgeneral-regs-only should be
 # used to avoid the use of the FPU and therefore seL4 does not have to
@@ -115,19 +118,21 @@ CFLAGS := -mstrict-align \
 		  -nostdlib \
 		  -Wno-unused-command-line-argument \
 		  -Wall -Wno-unused-function -Werror \
-		  -I$(VMM_SRC_DIR)/arch/aarch64 -I$(VMM_SRC_DIR) -I$(VMM_SRC_DIR)/util -I$(BOARD_DIR)/include \
-		  -I$(SDDF_SERIAL_RINGBUFFER)/include \
+		  -I$(VMM_SRC_DIR)/arch/aarch64 \
+		  -I$(VMM_SRC_DIR) -I$(VMM_SRC_DIR)/util \
+		  -I$(BOARD_DIR)/include \
 		  -I$(SDDF_SERIAL_DRIVER)/include \
 		  -I$(SDDF) \
 		  -I$(SDDF)/include \
 		  -DBOARD_$(BOARD) \
 		  -DCONFIG_$(CONFIG) \
-		  -target aarch64-none-elf
+		  -target aarch64-none-elf \
+		  -MD
 
 LDFLAGS := -L$(BOARD_DIR)/lib
 LIBS := -lmicrokit -Tmicrokit.ld
 
-all: directories $(IMAGE_FILE)
+all: $(IMAGE_FILE)
 
 qemu: all
 	# @ivanv: check that the amount of RAM given to QEMU is at least the number of RAM that QEMU is setup with for seL4.
@@ -139,8 +144,9 @@ qemu: all
 			-m size=2G \
 			-nographic
 
-directories:
-	$(shell mkdir -p $(BUILD_DIR))
+${BUILD_DIR}/directories: 
+	mkdir -p $(BUILD_DIR)
+	touch $@
 
 $(DTB): $(DTS)
 	if ! command -v $(DTC) &> /dev/null; then echo "Could not find dependency: Device Tree Compiler (dtc)"; exit 1; fi
@@ -155,44 +161,35 @@ $(BUILD_DIR)/package_guest_images.o: $(VMM_TOOLS)/package_guest_images.S $(IMAGE
 					-target aarch64-none-elf \
 					$< -o $@
 
-$(BUILD_DIR)/%.o: %.c Makefile
-	$(CC) -c $(CFLAGS) $< -o $@
-
-$(BUILD_DIR)/%.o: $(VMM_SRC_DIR)/%.c Makefile
-	$(CC) -c $(CFLAGS) $< -o $@
-
-$(BUILD_DIR)/%.o: $(VMM_SRC_DIR)/util/%.c Makefile
-	$(CC) -c $(CFLAGS) $< -o $@
+VPATH=${VMM_SRC_DIR}:${VMM_SRC_DIR}/util:${VMM_SRC_DIR}/arch/aarch64:${SDDF_SERIAL_DRIVER}:${SDDF_UTIL}:${VMM_SRC_DIR}/arch/aarch64/vgic:${VMM_SRC_DIR}/virtio
 
-$(BUILD_DIR)/%.o: $(VMM_SRC_DIR)/arch/aarch64/%.c Makefile
+$(BUILD_DIR)/%.o: %.c Makefile
 	$(CC) -c $(CFLAGS) $< -o $@
 
-$(BUILD_DIR)/%.o: $(VMM_SRC_DIR)/arch/aarch64/vgic/%.c Makefile
+${BUILD_DIR}/sddf_printf.o: ${SDDF_UTIL}/printf.c
 	$(CC) -c $(CFLAGS) $< -o $@
 
-$(BUILD_DIR)/%.o: $(VMM_SRC_DIR)/virtio/%.c Makefile
-	$(CC) -c $(CFLAGS) $< -o $@
 
 $(BUILD_DIR)/%.o: $(SDDF_SERIAL_COMPONENTS)/%.c Makefile
 	$(CC) -c $(CFLAGS) -DSERIAL_NUM_CLIENTS=2 -DSERIAL_TRANSFER_WITH_COLOUR=1 $< -o $@
 
-$(BUILD_DIR)/%.o: $(SDDF_SERIAL_RINGBUFFER)/%.c Makefile
-	$(CC) -c $(CFLAGS) $< -o $@
-
-$(BUILD_DIR)/%.o: $(SDDF_SERIAL_DRIVER)/%.c Makefile
-	$(CC) -c $(CFLAGS) $< -o $@
 
 $(BUILD_DIR)/vmm.elf: $(addprefix $(BUILD_DIR)/, $(VMM_OBJS))
 	$(LD) $(LDFLAGS) $^ $(LIBS) -o $@
 
-$(BUILD_DIR)/serial_mux_tx.elf: $(addprefix $(BUILD_DIR)/, $(SERIAL_MUX_TX_OBJS))
+$(BUILD_DIR)/serial_virt_tx.elf: $(addprefix $(BUILD_DIR)/, $(SERIAL_VIRT_TX_OBJS))
 	$(LD) $(LDFLAGS) $^ $(LIBS) -o $@
 
-$(BUILD_DIR)/serial_mux_rx.elf: $(addprefix $(BUILD_DIR)/, $(SERIAL_MUX_RX_OBJS))
+$(BUILD_DIR)/serial_virt_rx.elf: $(addprefix $(BUILD_DIR)/, $(SERIAL_VIRT_RX_OBJS))
 	$(LD) $(LDFLAGS) $^ $(LIBS) -o $@
 
 $(BUILD_DIR)/uart_driver.elf: $(addprefix $(BUILD_DIR)/, $(SERIAL_DRIVER_OBJS))
 	$(LD) $(LDFLAGS) $^ $(LIBS) -o $@
 
 $(IMAGE_FILE) $(REPORT_FILE): $(addprefix $(BUILD_DIR)/, $(ELFS)) $(SYSTEM_DESCRIPTION) $(IMAGE_DIR)
 	$(MICROKIT_TOOL) $(SYSTEM_DESCRIPTION) --search-path $(BUILD_DIR) $(IMAGE_DIR) --board $(BOARD) --config $(CONFIG) -o $(IMAGE_FILE) -r $(REPORT_FILE)
+
+${ALL_OBJS}: ${BUILD_DIR}/directories ${MAKEFILE}
+
+
+-include ${DEPENDS}
diff --git a/examples/virtio/board/qemu_arm_virt/virtio.system b/examples/virtio/board/qemu_arm_virt/virtio.system
@@ -14,11 +14,11 @@
         <program_image path="vmm.elf" />
         <map mr="guest_ram_1" vaddr="0x40000000" perms="rw" setvar_vaddr="guest_ram_vaddr" />
 
-        <!-- shared memory for ring buffer mechanism -->
+        <!-- shared memory for sDDF queues -->
         <map mr="rx_free_serial_vmm_1" vaddr="0x6_000_000" perms="rw" cached="true" setvar_vaddr="serial_rx_free" />
-        <map mr="rx_used_serial_vmm_1" vaddr="0x6_200_000" perms="rw" cached="true" setvar_vaddr="serial_rx_used" />
+        <map mr="rx_active_serial_vmm_1" vaddr="0x6_200_000" perms="rw" cached="true" setvar_vaddr="serial_rx_active" />
         <map mr="tx_free_serial_vmm_1" vaddr="0x103_400_000" perms="rw" cached="true" setvar_vaddr="serial_tx_free" />
-        <map mr="tx_used_serial_vmm_1" vaddr="0x103_600_000" perms="rw" cached="true" setvar_vaddr="serial_tx_used" />
+        <map mr="tx_active_serial_vmm_1" vaddr="0x103_600_000" perms="rw" cached="true" setvar_vaddr="serial_tx_active" />
         <!-- sDDF related regions for virtIO console -->
         <map mr="tx_data_serial_vmm_1" vaddr="0x8_400_000" perms="rw" cached="true" setvar_vaddr="serial_tx_data" />
         <map mr="rx_data_serial_vmm_1" vaddr="0x8_600_000" perms="rw" cached="true" setvar_vaddr="serial_rx_data" />
@@ -33,11 +33,11 @@
         <program_image path="vmm.elf" />
         <map mr="guest_ram_2" vaddr="0x40000000" perms="rw" setvar_vaddr="guest_ram_vaddr" />
 
-        <!-- shared memory for ring buffer mechanism -->
+        <!-- shared memory for queues -->
         <map mr="rx_free_serial_vmm_2" vaddr="0x6_000_000" perms="rw" cached="true" setvar_vaddr="serial_rx_free" />
-        <map mr="rx_used_serial_vmm_2" vaddr="0x6_200_000" perms="rw" cached="true" setvar_vaddr="serial_rx_used" />
+        <map mr="rx_active_serial_vmm_2" vaddr="0x6_200_000" perms="rw" cached="true" setvar_vaddr="serial_rx_active" />
         <map mr="tx_free_serial_vmm_2" vaddr="0x103_400_000" perms="rw" cached="true" setvar_vaddr="serial_tx_free" />
-        <map mr="tx_used_serial_vmm_2" vaddr="0x103_600_000" perms="rw" cached="true" setvar_vaddr="serial_tx_used" />
+        <map mr="tx_active_serial_vmm_2" vaddr="0x103_600_000" perms="rw" cached="true" setvar_vaddr="serial_tx_active" />
         <!-- sDDF related regions for virtIO console -->
         <map mr="tx_data_serial_vmm_2" vaddr="0x8_800_000" perms="rw" cached="true" setvar_vaddr="serial_tx_data" />
         <map mr="rx_data_serial_vmm_2" vaddr="0x8_a00_000" perms="rw" cached="true" setvar_vaddr="serial_rx_data" />
@@ -55,55 +55,55 @@
     <memory_region name="rx_data_serial_vmm_1" size="0x200_000" page_size="0x200_000" />
     <memory_region name="tx_data_serial_vmm_2" size="0x200_000" page_size="0x200_000" />
     <memory_region name="rx_data_serial_vmm_2" size="0x200_000" page_size="0x200_000" />
-    <!-- Regions for the shared ring buffers used by the driver and multiplexor -->
+    <!-- Regions for the queues used by the driver and virtualiser -->
     <memory_region name="rx_free_serial_driver" size="0x200_000" page_size="0x200_000"/>
-    <memory_region name="rx_used_serial_driver" size="0x200_000" page_size="0x200_000"/>
+    <memory_region name="rx_active_serial_driver" size="0x200_000" page_size="0x200_000"/>
     <memory_region name="tx_free_serial_driver" size="0x200_000" page_size="0x200_000"/>
-    <memory_region name="tx_used_serial_driver" size="0x200_000" page_size="0x200_000"/>
+    <memory_region name="tx_active_serial_driver" size="0x200_000" page_size="0x200_000"/>
     <!--
-        Regions for the shared ring buffers used by the multiplexor and the
+        Regions for the shared queues used by the virtualiser and the
         client (in this case the client is the VMM)
     -->
     <memory_region name="tx_free_serial_vmm_1" size="0x200_000" page_size="0x200_000"/>
-    <memory_region name="tx_used_serial_vmm_1" size="0x200_000" page_size="0x200_000"/>
+    <memory_region name="tx_active_serial_vmm_1" size="0x200_000" page_size="0x200_000"/>
     <memory_region name="rx_free_serial_vmm_1" size="0x200_000" page_size="0x200_000"/>
-    <memory_region name="rx_used_serial_vmm_1" size="0x200_000" page_size="0x200_000"/>
+    <memory_region name="rx_active_serial_vmm_1" size="0x200_000" page_size="0x200_000"/>
 
     <memory_region name="tx_free_serial_vmm_2" size="0x200_000" page_size="0x200_000"/>
-    <memory_region name="tx_used_serial_vmm_2" size="0x200_000" page_size="0x200_000"/>
+    <memory_region name="tx_active_serial_vmm_2" size="0x200_000" page_size="0x200_000"/>
     <memory_region name="rx_free_serial_vmm_2" size="0x200_000" page_size="0x200_000"/>
-    <memory_region name="rx_used_serial_vmm_2" size="0x200_000" page_size="0x200_000"/>
+    <memory_region name="rx_active_serial_vmm_2" size="0x200_000" page_size="0x200_000"/>
 
-    <!-- Multiplexor for transmit (TX) serial data -->
-    <protection_domain name="serial_mux_tx" priority="100" pp="true">
-        <program_image path="serial_mux_tx.elf" />
-         <!-- shared memory for driver/mux ring buffer mechanism -->
+    <!-- Virtualiser for transmit (TX) serial data -->
+    <protection_domain name="serial_virt_tx" priority="100" pp="true">
+        <program_image path="serial_virt_tx.elf" />
+         <!-- shared memory for driver/virt queues -->
         <map mr="tx_free_serial_driver" vaddr="0x4_400_000" perms="rw" cached="true" setvar_vaddr="tx_free_driver" />
-        <map mr="tx_used_serial_driver" vaddr="0x4_600_000" perms="rw" cached="true" setvar_vaddr="tx_used_driver" />
-        <!-- shared memory for mux/client ring buffer mechanism -->
-        <!-- Ring buffers between the multiplexor and VMM client  -->
+        <map mr="tx_active_serial_driver" vaddr="0x4_600_000" perms="rw" cached="true" setvar_vaddr="tx_active_driver" />
+        <!-- shared memory for virt/client queues -->
+        <!-- Queues between the virtualiser and VMM client  -->
         <map mr="tx_free_serial_vmm_1" vaddr="0x103_400_000" perms="rw" cached="true" setvar_vaddr="tx_free_client" />
-        <map mr="tx_used_serial_vmm_1" vaddr="0x103_600_000" perms="rw" cached="true" setvar_vaddr="tx_used_client" />
+        <map mr="tx_active_serial_vmm_1" vaddr="0x103_600_000" perms="rw" cached="true" setvar_vaddr="tx_active_client" />
         <map mr="tx_free_serial_vmm_2" vaddr="0x5_200_000" perms="rw" cached="true" setvar_vaddr="tx_free_client2" />
-        <map mr="tx_used_serial_vmm_2" vaddr="0x5_400_000" perms="rw" cached="true" setvar_vaddr="tx_used_client2" />
-        <!-- Data regions between multiplexor/driver and vmm/mulitplexor -->
+        <map mr="tx_active_serial_vmm_2" vaddr="0x5_400_000" perms="rw" cached="true" setvar_vaddr="tx_active_client2" />
+        <!-- Data regions between virtualiser/driver and vmm/virtualiser -->
         <map mr="tx_data_driver" vaddr="0x2_200_000" perms="rw" cached="true" setvar_vaddr="tx_data_driver" />
         <!-- @ivanv: the virtual address of the data region needs to match what it is in the client as well,
              this is very fragile and should be fixed. -->
         <map mr="tx_data_serial_vmm_1" vaddr="0x8_400_000" perms="rw" cached="true" setvar_vaddr="tx_data_client" />
         <map mr="tx_data_serial_vmm_2" vaddr="0x8_800_000" perms="rw" cached="true" setvar_vaddr="tx_data_client2" />
     </protection_domain>
-    <!-- Multiplexor for receive (RX) serial data -->
-    <protection_domain name="serial_mux_rx" priority="100" pp="true">
-        <program_image path="serial_mux_rx.elf" />
-         <!-- shared memory for driver/mux ring buffer mechanism -->
+    <!-- Virtualiser for receive (RX) serial data -->
+    <protection_domain name="serial_virt_rx" priority="100" pp="true">
+        <program_image path="serial_virt_rx.elf" />
+         <!-- shared memory for driver/virt queues -->
         <map mr="rx_free_serial_driver" vaddr="0x4_000_000" perms="rw" cached="true" setvar_vaddr="rx_free_driver" />
-        <map mr="rx_used_serial_driver" vaddr="0x4_200_000" perms="rw" cached="true" setvar_vaddr="rx_used_driver" />
-        <!-- Ring buffers between the multiplexor and VMM client  -->
+        <map mr="rx_active_serial_driver" vaddr="0x4_200_000" perms="rw" cached="true" setvar_vaddr="rx_active_driver" />
+        <!-- Queues between the virtualiser and VMM client  -->
         <map mr="rx_free_serial_vmm_1" vaddr="0x4_800_000" perms="rw" cached="true" setvar_vaddr="rx_free_client" />
-        <map mr="rx_used_serial_vmm_1" vaddr="0x5_000_000" perms="rw" cached="true" setvar_vaddr="rx_used_client" />
+        <map mr="rx_active_serial_vmm_1" vaddr="0x5_000_000" perms="rw" cached="true" setvar_vaddr="rx_active_client" />
         <map mr="rx_free_serial_vmm_2" vaddr="0x5_200_000" perms="rw" cached="true" setvar_vaddr="rx_free_client2" />
-        <map mr="rx_used_serial_vmm_2" vaddr="0x5_400_000" perms="rw" cached="true" setvar_vaddr="rx_used_client2" />
+        <map mr="rx_active_serial_vmm_2" vaddr="0x5_400_000" perms="rw" cached="true" setvar_vaddr="rx_active_client2" />
 
         <map mr="rx_data_driver" vaddr="0x2_600_000" perms="rw" cached="true" setvar_vaddr="rx_data_driver" />
         <map mr="rx_data_serial_vmm_1" vaddr="0x8_600_000" perms="rw" cached="true" setvar_vaddr="rx_data_client" />
@@ -116,42 +116,42 @@
         <!-- Data region -->
         <map mr="tx_data_driver" vaddr="0x2_200_000" perms="rw" cached="true" />
         <map mr="rx_data_driver" vaddr="0x2_600_000" perms="rw" cached="true" />
-        <!-- shared memory for ring buffer mechanism -->
+        <!-- shared memory for queues -->
         <map mr="rx_free_serial_driver" vaddr="0x4_000_000" perms="rw" cached="true" setvar_vaddr="rx_free" />
-        <map mr="rx_used_serial_driver" vaddr="0x4_200_000" perms="rw" cached="true" setvar_vaddr="rx_used" />
+        <map mr="rx_active_serial_driver" vaddr="0x4_200_000" perms="rw" cached="true" setvar_vaddr="rx_active" />
         <map mr="tx_free_serial_driver" vaddr="0x4_400_000" perms="rw" cached="true" setvar_vaddr="tx_free" />
-        <map mr="tx_used_serial_driver" vaddr="0x4_600_000" perms="rw" cached="true" setvar_vaddr="tx_used" />
+        <map mr="tx_active_serial_driver" vaddr="0x4_600_000" perms="rw" cached="true" setvar_vaddr="tx_active" />
         <!-- UART IRQ -->
         <irq irq="33" id="1" />
     </protection_domain>
 
     <channel>
         <end pd="VMM-1" id="1"/>
-        <end pd="serial_mux_tx" id="1"/>
+        <end pd="serial_virt_tx" id="1"/>
     </channel>
 
     <channel>
         <end pd="VMM-2" id="1"/>
-        <end pd="serial_mux_tx" id="2"/>
+        <end pd="serial_virt_tx" id="2"/>
     </channel>
 
     <channel>
         <end pd="uart_driver" id="8"/>
-        <end pd="serial_mux_tx" id="9"/>
+        <end pd="serial_virt_tx" id="9"/>
     </channel>
 
     <channel>
         <end pd="VMM-1" id="2"/>
-        <end pd="serial_mux_rx" id="1"/>
+        <end pd="serial_virt_rx" id="1"/>
     </channel>
 
     <channel>
         <end pd="VMM-2" id="2"/>
-        <end pd="serial_mux_rx" id="2"/>
+        <end pd="serial_virt_rx" id="2"/>
     </channel>
 
     <channel>
         <end pd="uart_driver" id="10"/>
-        <end pd="serial_mux_rx" id="11"/>
+        <end pd="serial_virt_rx" id="11"/>
     </channel>
 </system>
diff --git a/examples/virtio/sddf b/examples/virtio/sddf
diff --git a/examples/virtio/vmm.c b/examples/virtio/vmm.c
@@ -16,7 +16,7 @@
 #include "vcpu.h"
 #include "virtio/virtio.h"
 #include "virtio/console.h"
-#include <sddf/serial/shared_ringbuffer.h>
+#include <sddf/serial/queue.h>
 
 /*
  * As this is just an example, for simplicity we just make the size of the
@@ -45,18 +45,18 @@ extern char _guest_initrd_image_end[];
 uintptr_t guest_ram_vaddr;
 
 uintptr_t serial_rx_free;
-uintptr_t serial_rx_used;
+uintptr_t serial_rx_active;
 uintptr_t serial_tx_free;
-uintptr_t serial_tx_used;
+uintptr_t serial_tx_active;
 
 uintptr_t serial_rx_data;
 uintptr_t serial_tx_data;
 
-ring_handle_t serial_rx_ring;
-ring_handle_t serial_tx_ring;
+serial_queue_handle_t serial_rx_queue;
+serial_queue_handle_t serial_tx_queue;
 
-#define SERIAL_MUX_TX_CH 1
-#define SERIAL_MUX_RX_CH 2
+#define SERIAL_VIRT_TX_CH 1
+#define SERIAL_VIRT_RX_CH 2
 
 #define VIRTIO_CONSOLE_IRQ (74)
 #define VIRTIO_CONSOLE_BASE (0x130000)
@@ -91,39 +91,39 @@ void init(void) {
         LOG_VMM_ERR("Failed to initialise emulated interrupt controller\n");
         return;
     }
-    /* Initialise our sDDF ring buffers for the serial device */
-    ring_init(&serial_rx_ring, (ring_buffer_t *)serial_rx_free, (ring_buffer_t *)serial_rx_used, true, NUM_BUFFERS, NUM_BUFFERS);
-    for (int i = 0; i < NUM_BUFFERS - 1; i++) {
-        int ret = enqueue_free(&serial_rx_ring, serial_rx_data + (i * BUFFER_SIZE), BUFFER_SIZE, NULL);
+    /* Initialise our sDDF queue for the serial device */
+    serial_queue_init(&serial_rx_queue, (serial_queue_t *)serial_rx_free, (serial_queue_t *)serial_rx_active, true, NUM_ENTRIES, NUM_ENTRIES);
+    for (int i = 0; i < NUM_ENTRIES - 1; i++) {
+        int ret = serial_enqueue_free(&serial_rx_queue, serial_rx_data + (i * BUFFER_SIZE), BUFFER_SIZE);
         if (ret != 0) {
             microkit_dbg_puts(microkit_name);
             microkit_dbg_puts(": server rx buffer population, unable to enqueue buffer\n");
         }
     }
-    ring_init(&serial_tx_ring, (ring_buffer_t *)serial_tx_free, (ring_buffer_t *)serial_tx_used, true, NUM_BUFFERS, NUM_BUFFERS);
-    for (int i = 0; i < NUM_BUFFERS - 1; i++) {
+    serial_queue_init(&serial_tx_queue, (serial_queue_t *)serial_tx_free, (serial_queue_t *)serial_tx_active, true, NUM_ENTRIES, NUM_ENTRIES);
+    for (int i = 0; i < NUM_ENTRIES - 1; i++) {
         // Have to start at the memory region left of by the rx ring
-        int ret = enqueue_free(&serial_tx_ring, serial_tx_data + ((i + NUM_BUFFERS) * BUFFER_SIZE), BUFFER_SIZE, NULL);
+        int ret = serial_enqueue_free(&serial_tx_queue, serial_tx_data + ((i + NUM_ENTRIES) * BUFFER_SIZE), BUFFER_SIZE);
         assert(ret == 0);
         if (ret != 0) {
             microkit_dbg_puts(microkit_name);
             microkit_dbg_puts(": server tx buffer population, unable to enqueue buffer\n");
         }
     }
     /* Neither ring should be plugged and hence all buffers we send should actually end up at the driver. */
-    assert(!ring_plugged(serial_tx_ring.free_ring));
-    assert(!ring_plugged(serial_tx_ring.used_ring));
+    assert(!serial_queue_plugged(serial_tx_queue.free));
+    assert(!serial_queue_plugged(serial_tx_queue.active));
     /* Initialise virtIO console device */
     success = virtio_mmio_device_init(&virtio_console, CONSOLE, VIRTIO_CONSOLE_BASE, VIRTIO_CONSOLE_SIZE, VIRTIO_CONSOLE_IRQ,
-                                      &serial_rx_ring, &serial_tx_ring, SERIAL_MUX_TX_CH);
+                                      &serial_rx_queue, &serial_tx_queue, SERIAL_VIRT_TX_CH);
     assert(success);
     /* Finally start the guest */
     guest_start(GUEST_VCPU_ID, kernel_pc, GUEST_DTB_VADDR, GUEST_INIT_RAM_DISK_VADDR);
 }
 
 void notified(microkit_channel ch) {
     switch (ch) {
-        case SERIAL_MUX_RX_CH: {
+        case SERIAL_VIRT_RX_CH: {
             /* We have received an event from the serial multipelxor, so we
              * call the virtIO console handling */
             virtio_console_handle_rx(&virtio_console);