Merge remote-tracking branch 'guttatus/dynamic' into nemu

refactor(prototyper): split BootInfo to BootInfo and BootHart

Signed-off-by: Woshiluo Luo <woshiluo.luo@outlook.com>

prototyper/src/fail.rs

@@ -73,3 +73,15 @@ pub fn no_dynamic_info_available(err: dynamic::DynamicReadError) -> dynamic::Dyn
     }
     reset::fail()
 }
+
+#[cold]
+pub fn use_lottery(_err: dynamic::DynamicReadError) -> dynamic::DynamicInfo {
+    dynamic::DynamicInfo {
+        magic: 0,
+        version: 0,
+        next_addr: 0,
+        next_mode: 0,
+        options: 0,
+        boot_hart: usize::MAX,
+    }
+}

prototyper/src/main.rs

@@ -38,12 +38,10 @@ extern "C" fn rust_main(_hart_id: usize, opaque: usize, nonstandard_a2: usize) {
     // parse dynamic information
     static SBI_READY: AtomicBool = AtomicBool::new(false);
 
-    let boot_info = platform::get_boot_info(opaque, nonstandard_a2);
+    let boot_hart_info = platform::get_boot_hart(opaque, nonstandard_a2);
 
-    if boot_info.is_boot_hart {
-        let mpp = boot_info.mpp;
-        let next_addr = boot_info.next_address;
-        let fdt_addr = boot_info.fdt_address;
+    if boot_hart_info.is_boot_hart {
+        let fdt_addr = boot_hart_info.fdt_address;
 
         // 1. Init FDT
         // parse the device tree
@@ -129,6 +127,8 @@ extern "C" fn rust_main(_hart_id: usize, opaque: usize, nonstandard_a2: usize) {
         // 设置陷入栈
         trap_stack::prepare_for_trap();
 
+        let boot_info = platform::get_boot_info(nonstandard_a2);
+        let (mpp, next_addr) = (boot_info.mpp, boot_info.next_address);
         // 设置内核入口
         local_remote_hsm().start(NextStage {
             start_addr: next_addr,
@@ -156,7 +156,9 @@ extern "C" fn rust_main(_hart_id: usize, opaque: usize, nonstandard_a2: usize) {
         trap_stack::prepare_for_trap();
 
         // waiting for sbi ready
-        while !SBI_READY.load(Ordering::Relaxed) { core::hint::spin_loop() }
+        while !SBI_READY.load(Ordering::Relaxed) {
+            core::hint::spin_loop()
+        }
     }
 
     ipi::clear_all();
@@ -181,48 +183,6 @@ extern "C" fn rust_main(_hart_id: usize, opaque: usize, nonstandard_a2: usize) {
 #[naked]
 #[link_section = ".text.entry"]
 #[export_name = "_start"]
-#[cfg(not(feature = "payload"))]
-unsafe extern "C" fn start() -> ! {
-    core::arch::asm!(
-        // 1. Turn off interrupt
-        "   csrw    mie, zero",
-        // 2. Initialize programming langauge runtime
-        // only clear bss if hartid matches preferred boot hart id
-        "   csrr    t0, mhartid",
-        "   ld      t1, 0(a2)",
-        "   li      t2, {magic}",
-        "   bne     t1, t2, 3f",
-        "   ld      t2, 40(a2)",
-        "   bne     t0, t2, 2f",
-        "   j       4f",
-        "3:",
-        "   j       3b", // TODO multi hart preempt for runtime init
-        "4:",
-        // 3. clear bss segment
-        "   la      t0, sbss
-            la      t1, ebss
-        1:  bgeu    t0, t1, 2f
-            sd      zero, 0(t0)
-            addi    t0, t0, 8
-            j       1b",
-        "2:",
-         // 4. Prepare stack for each hart
-        "   call    {locate_stack}",
-        "   call    {main}",
-        "   csrw    mscratch, sp",
-        "   j       {hart_boot}",
-        magic = const dynamic::MAGIC,
-        locate_stack = sym trap_stack::locate,
-        main         = sym rust_main,
-        hart_boot    = sym trap::msoft,
-        options(noreturn)
-    )
-}
-
-#[naked]
-#[link_section = ".text.entry"]
-#[export_name = "_start"]
-#[cfg(feature = "payload")]
 unsafe extern "C" fn start() -> ! {
     core::arch::asm!(
         // 1. Turn off interrupt
@@ -230,19 +190,34 @@ unsafe extern "C" fn start() -> ! {
         // 2. Initialize programming langauge runtime
         // only clear bss if hartid matches preferred boot hart id
         "   csrr    t0, mhartid",
-        // 3. clear bss segment
+        "   bne     t0, zero, 4f",
+        "1:",
+        // 3. Hart 0 clear bss segment
         "   la      t0, sbss
             la      t1, ebss
-        1:  bgeu    t0, t1, 2f
+         2: bgeu    t0, t1, 3f
             sd      zero, 0(t0)
             addi    t0, t0, 8
-            j       1b",
-        "2:",
+            j       2b",
+        "3: ", // Hart 0 set bss ready signal
+        "   la      t0, 6f
+            li      t1, 1
+            amoadd.w t0, t1, 0(t0)
+            j       5f",
+        "4:", // Other harts are waiting for bss ready signal
+        "   li      t1, 1
+            la      t0, 6f
+            lw      t0, 0(t0)
+            bne     t0, t1, 4b", 
+        "5:",
          // 4. Prepare stack for each hart
         "   call    {locate_stack}",
         "   call    {main}",
         "   csrw    mscratch, sp",
         "   j       {hart_boot}",
+        "  .balign  4",
+        "6:",  // bss ready signal
+        "  .word    0",
         locate_stack = sym trap_stack::locate,
         main         = sym rust_main,
         hart_boot    = sym trap::msoft,

prototyper/src/platform/dynamic.rs

@@ -3,26 +3,33 @@
 use core::ops::Range;
 use core::sync::atomic::{AtomicBool, Ordering};
 
-use super::BootInfo;
+use super::{BootHart, BootInfo};
 use crate::fail;
 use crate::riscv_spec::current_hartid;
 
 use riscv::register::mstatus;
 
-pub fn get_boot_info(opaque: usize, nonstandard_a2: usize) -> BootInfo {
+pub fn get_boot_hart(opaque: usize, nonstandard_a2: usize) -> BootHart {
     static GENESIS: AtomicBool = AtomicBool::new(true);
-    let info = read_paddr(nonstandard_a2).unwrap_or_else(fail::no_dynamic_info_available);
+    let info = read_paddr(nonstandard_a2).unwrap_or_else(fail::use_lottery);
     let is_boot_hart = if info.boot_hart == usize::MAX {
         GENESIS.swap(false, Ordering::AcqRel)
     } else {
         current_hartid() == info.boot_hart
     };
-    let (mpp, next_addr) = mpp_next_addr(&info).unwrap_or_else(fail::invalid_dynamic_data);
-    BootInfo {
+    BootHart {
         fdt_address: opaque,
+        is_boot_hart,
+    }
+}
+
+pub fn get_boot_info(nonstandard_a2: usize) -> BootInfo {
+    static GENESIS: AtomicBool = AtomicBool::new(true);
+    let dynamic_info = read_paddr(nonstandard_a2).unwrap_or_else(fail::no_dynamic_info_available);
+    let (mpp, next_addr) = mpp_next_addr(&dynamic_info).unwrap_or_else(fail::invalid_dynamic_data);
+    BootInfo {
         next_address: next_addr,
         mpp,
-        is_boot_hart,
     }
 }
 

prototyper/src/platform/mod.rs

@@ -7,12 +7,15 @@ use riscv::register::mstatus;
 
 pub struct BootInfo {
     pub next_address: usize,
+    pub mpp: mstatus::MPP,
+}
+
+pub struct BootHart {
     pub fdt_address: usize,
     pub is_boot_hart: bool,
-    pub mpp: mstatus::MPP,
 }
 
 #[cfg(not(feature = "payload"))]
-pub use dynamic::get_boot_info;
+pub use dynamic::{get_boot_hart, get_boot_info};
 #[cfg(feature = "payload")]
-pub use payload::get_boot_info;
+pub use payload::{get_boot_hart, get_boot_info};

prototyper/src/platform/payload.rs

@@ -1,14 +1,19 @@
-use super::BootInfo;
+use super::{BootHart, BootInfo};
 use core::arch::asm;
 
 use riscv::register::mstatus;
 
-pub fn get_boot_info(_opaque: usize, _nonstandard_a2: usize) -> BootInfo {
-    BootInfo {
+pub fn get_boot_hart(_opaque: usize, _nonstandard_a2: usize) -> BootHart {
+    BootHart {
         fdt_address: get_fdt_address(),
+        is_boot_hart: true,
+    }
+}
+
+pub fn get_boot_info(_nonstandard_a2: usize) -> BootInfo {
+    BootInfo {
         next_address: get_image_address(),
         mpp: mstatus::MPP::Supervisor,
-        is_boot_hart: true,
     }
 }