Extract serial driver and add mipssim board for mipsel

Signed-off-by: Harry Chen <i@harrychen.xyz>

kernel/Cargo.lock

@@ -230,7 +230,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "mips"
 version = "0.1.0"
-source = "git+https://github.com/Harry-Chen/rust-mips#e2cea12fc88f1f5a788a155972cd4047e7ad2b4f"
+source = "git+https://github.com/Harry-Chen/rust-mips#bee9865920bceef12dbb527c1c237de905129c0b"
 dependencies = [
  "bit_field 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",

kernel/Cargo.toml

@@ -26,8 +26,9 @@ board_u540 = ["sv39", "link_user"]
 nographic = []
 board_raspi3 = ["bcm2837", "link_user"]
 raspi3_use_generic_timer = ["bcm2837/use_generic_timer"]
-# for mipsel qemu malta machine
+# for qemu machine
 board_malta = ["link_user"]
+board_mipssim = ["link_user"]
 # for thinpad
 board_thinpad = ["link_user"]
 # Hard link user program

kernel/Makefile

@@ -68,6 +68,11 @@ ifeq ($(arch), mipsel)
 dtb := src/arch/$(arch)/board/$(board)/device.dtb
 endif
 
+# mipssim does not support SMP
+ifeq ($(board), mipssim)
+smp := 1
+endif
+
 export ARCH = $(arch)
 export BOARD = $(board)
 export SMP = $(smp)
@@ -129,7 +134,7 @@ qemu_opts += \
 	-kernel $(kernel_img)
 
 else ifeq ($(arch), mipsel)
-ifeq ($(board), malta)
+ifeq ($(board), $(filter $(board), malta mipssim))
 qemu_opts += \
 	-machine $(board) \
 	-serial mon:stdio \

kernel/src/arch/mipsel/board/malta/consts.rs

@@ -1,3 +1,3 @@
-/// board specific constants for malta
+/// board specific constants
 pub const MEMORY_END: usize = 0x8800_0000;
 pub const KERNEL_HEAP_SIZE: usize = 0x00a0_0000;

kernel/src/arch/mipsel/board/malta/mod.rs

@@ -1,6 +1,7 @@
 use once::*;
 use alloc::string::String;
 
+#[path = "../../../../drivers/serial/16550_reg.rs"]
 pub mod serial;
 #[path = "../../../../drivers/gpu/fb.rs"]
 pub mod fb;
@@ -21,6 +22,6 @@ pub fn init_driver() {
     // timer::init();
 }
 
-pub fn probe_fb_info(width: u32, height: u32, depth: u32) -> Result<(fb::FramebufferInfo, usize), String> {
+pub fn probe_fb_info(_width: u32, _height: u32, _depth: u32) -> Result<(fb::FramebufferInfo, usize), String> {
     Err(String::from("Framebuffer not usable on malta board"))
 }

kernel/src/arch/mipsel/board/mipssim/consts.rs

@@ -0,0 +1,3 @@
+/// board specific constants
+pub const MEMORY_END: usize = 0x8800_0000;
+pub const KERNEL_HEAP_SIZE: usize = 0x00a0_0000;

kernel/src/arch/mipsel/board/mipssim/device.dts

@@ -0,0 +1,36 @@
+/dts-v1/;
+
+
+/ {
+	model = "qemu mipssim";
+	compatible = "qemu,mipssim";
+    #address-cells = <1>;
+    #size-cells = <1>;
+
+	chosen {
+		stdio = &uart0;
+	};
+
+    aliases { };
+
+    cpu_intc: interrupt-controller {
+		compatible = "mti,cpu-interrupt-controller";
+		interrupt-controller;
+		#interrupt-cells = <1>;
+	};
+
+	main_memory: memory@0 {
+        device_type = "memory";
+		reg = <0x00000000 0x10000000>;
+	};
+
+	uart0: serial@bfd003f8 {
+		compatible = "ns16550a";
+		reg = <0xbfd003f8 0x8>;
+		clock-frequency = <1843200>;
+		/* attached to the MIPS CPU INT2 pin, ie interrupt 4 */
+        interrupt-parent = <&cpu_intc>;
+        interrupts = <4>;
+	};
+
+};

kernel/src/arch/mipsel/board/mipssim/mod.rs

@@ -0,0 +1,27 @@
+use once::*;
+use alloc::string::String;
+
+#[path = "../../../../drivers/serial/16550_reg.rs"]
+pub mod serial;
+#[path = "../../../../drivers/gpu/fb.rs"]
+pub mod fb;
+#[path = "../../../../drivers/console/mod.rs"]
+pub mod console;
+pub mod consts;
+
+/// Initialize serial port first
+pub fn init_serial_early() {
+    assert_has_not_been_called!("board::init must be called only once");
+    serial::init(0xbfd003f8);
+    println!("Hello QEMU MIPSSIM!");
+}
+
+/// Initialize other board drivers
+pub fn init_driver() {
+    // TODO: add possibly more drivers
+    // timer::init();
+}
+
+pub fn probe_fb_info(_width: u32, _height: u32, _depth: u32) -> Result<(fb::FramebufferInfo, usize), String> {
+    Err(String::from("Framebuffer not usable on mipssim board"))
+}

kernel/src/arch/mipsel/board/thinpad/consts.rs

@@ -1,3 +1,3 @@
-/// board specific constants for thinpad
+/// board specific constants
 pub const MEMORY_END: usize = 0x8080_0000;
 pub const KERNEL_HEAP_SIZE: usize = 0x0020_0000;

kernel/src/arch/mipsel/board/thinpad/mod.rs

@@ -1,6 +1,7 @@
 use once::*;
 use alloc::string::String;
 
+#[path = "../../../../drivers/serial/simple_uart.rs"]
 pub mod serial;
 #[path = "../../../../drivers/gpu/fb.rs"]
 pub mod fb;

kernel/src/arch/mipsel/mod.rs

@@ -22,6 +22,11 @@ pub mod board;
 #[path = "board/thinpad/mod.rs"]
 pub mod board;
 
+#[cfg(feature = "board_mipssim")]
+#[path = "board/mipssim/mod.rs"]
+pub mod board;
+
+
 extern "C" {
     fn _dtb_start();
     fn _dtb_end();