Add initial support for Rocket Chip platform

kernel/Cargo.toml

@@ -24,6 +24,7 @@ default = ["sv39"]
 sv39 = []
 board_u540 = ["sv39", "link_user"]
 board_k210 = ["sv39", "link_user"]
+board_rocket_chip = ["sv39", "link_user"]
 # (for aarch64 RaspberryPi3)
 nographic = []
 board_raspi3 = ["bcm2837", "link_user"]

kernel/Makefile

@@ -26,6 +26,7 @@
 #         | pc                   Only available on x86_64, run on real pc
 #         | u540                 Only available on riscv64, run on HiFive U540, use Sv39
 #         | k210                 Only available on riscv64, run on K210, use Sv39
+#         | rocket_chip          Only available on riscv64, run on Rocket Chip, use Sv39
 #         | raspi3               Only available on aarch64, run on Raspberry Pi 3 Model B/B+
 #   pci_passthru = 0000:00:00.1  Only available on x86_64, passthrough the specified PCI device
 #   init = /bin/ls               Only available on riscv64, run specified program instead of user shell
@@ -60,7 +61,7 @@ ifeq ($(arch), $(filter $(arch), aarch64 mipsel))
 export SFSIMG = $(user_dir)/build/$(arch).img
 else
 # board is pc or qemu?
-ifeq ($(board), $(filter $(board), pc u540 k210))
+ifeq ($(board), $(filter $(board), pc u540 k210 rocket_chip))
 #link user img, so use original image
 export SFSIMG = $(user_dir)/build/$(arch).img
 else

kernel/src/arch/riscv32/memory.rs

@@ -92,6 +92,8 @@ fn remap_the_kernel(dtb: usize) {
         Linear::new(offset),
         "bss",
     );
+    // TODO: dtb on rocket chip
+    #[cfg(not(feature = "board_rocket_chip"))]
     ms.push(
         dtb,
         dtb + super::consts::MAX_DTB_SIZE,

kernel/src/arch/riscv32/mod.rs

@@ -53,10 +53,11 @@ pub extern "C" fn rust_main(hartid: usize, device_tree_paddr: usize) -> ! {
     memory::init(device_tree_vaddr);
     timer::init();
     // FIXME: init driver on u540
-    #[cfg(not(feature = "board_u540"))]
+    #[cfg(not(any(feature = "board_u540", feature = "board_rocket_chip")))]
     crate::drivers::init(device_tree_vaddr);
     #[cfg(not(feature = "board_k210"))]
     unsafe {
+        #[cfg(not(feature = "board_rocket_chip"))]
         board::enable_serial_interrupt();
         board::init_external_interrupt();
     }