feat(prototyper): use pmp to protect self

fix(prototyper): update nemu build options

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

Makefile.toml

@@ -7,7 +7,8 @@ args = ["clean"]
 
 [tasks.prototyper-nemu-build]
 command = "cargo"
-args = ["build", "-prustsbi-prototyper", "--release", "--features=nemu,payload"]
+args = ["build", "-prustsbi-prototyper", "--release", "--target", "riscv64imac-unknown-none-elf", "-Zbuild-std=core", "--features=nemu,payload"]
+env = {"RUSTFLAGS"="-C relocation-model=pie -C link-arg=-pie" }
 
 [tasks.prototyper-nemu]
 command = "rust-objcopy"

prototyper/build.rs

@@ -11,11 +11,11 @@ fn main() {
     println!("cargo:rustc-link-search={}", out.display());
 }
 
-#[cfg(feature = "payload")]
 const LINKER_SCRIPT: &[u8] = b"OUTPUT_ARCH(riscv)
 ENTRY(_start) 
 SECTIONS {
     . = 0x80000000;
+    sbi_start = .;
     .text : ALIGN(8) { 
         *(.text.entry)
         *(.text .text.*)
@@ -34,6 +34,7 @@ SECTIONS {
         *(.rela*)
         __rel_dyn_end = .;
     }
+
     erodata = .;
     .data : ALIGN(8) { 
         sdata = .;
@@ -53,6 +54,9 @@ SECTIONS {
     /DISCARD/ : {
         *(.eh_frame)
     }
+
+    sbi_end = .;
+
     .text 0x80100000 : ALIGN(8) {
         *(.fw_fdt)
     }
@@ -60,49 +64,3 @@ SECTIONS {
         *(.payload)
     }
 }";
-
-#[cfg(not(feature = "payload"))]
-const LINKER_SCRIPT: &[u8] = b"OUTPUT_ARCH(riscv)
-ENTRY(_start) 
-SECTIONS {
-    . = 0x80000000;
-    .text : ALIGN(8) { 
-        *(.text.entry)
-        *(.text .text.*)
-    }
-    .rodata : ALIGN(8) { 
-        srodata = .;
-        *(.rodata .rodata.*)
-        *(.srodata .srodata.*)
-        . = ALIGN(8);  
-    } 
-    .dynsym : ALIGN(8) {
-        *(.dynsym)
-    }
-    .rela.dyn : ALIGN(8) {
-        __rel_dyn_start = .;
-        *(.rela*)
-        __rel_dyn_end = .;
-    }
-
-    erodata = .;
-
-    .data : ALIGN(8) { 
-        sdata = .;
-        *(.data .data.*)
-        *(.sdata .sdata.*)
-        . = ALIGN(8); 
-        edata = .;
-    }
-    sidata = LOADADDR(.data);
-    .bss (NOLOAD) : ALIGN(8) {  
-        *(.bss.uninit)
-        sbss = .;
-        *(.bss .bss.*)
-        *(.sbss .sbss.*)
-        ebss = .;
-    } 
-    /DISCARD/ : {
-        *(.eh_frame)
-    }
-}";

prototyper/src/main.rs

@@ -114,14 +114,7 @@ extern "C" fn rust_main(_hart_id: usize, opaque: usize, nonstandard_a2: usize) {
                 .unwrap_or("<unspecified>")
         );
 
-        // TODO: PMP configuration needs to be obtained through the memory range in the device tree
-        use riscv::register::*;
-        unsafe {
-            pmpcfg0::set_pmp(0, Range::OFF, Permission::NONE, false);
-            pmpaddr0::write(0);
-            pmpcfg0::set_pmp(1, Range::TOR, Permission::RWX, false);
-            pmpaddr1::write(usize::MAX >> 2);
-        }
+        platform::set_pmp();
 
         // Get boot information and prepare for kernel entry.
         let boot_info = platform::get_boot_info(nonstandard_a2);
@@ -141,24 +134,15 @@ extern "C" fn rust_main(_hart_id: usize, opaque: usize, nonstandard_a2: usize) {
             mpp
         );
     } else {
-        // Non-boot hart initialization path.
-
-        // TODO: PMP configuration needs to be obtained through the memory range in the device tree.
-        use riscv::register::*;
-        unsafe {
-            pmpcfg0::set_pmp(0, Range::OFF, Permission::NONE, false);
-            pmpaddr0::write(0);
-            pmpcfg0::set_pmp(1, Range::TOR, Permission::RWX, false);
-            pmpaddr1::write(usize::MAX >> 2);
-        }
-
-        // Setup trap handling.
+        // 设置陷入栈
         trap_stack::prepare_for_trap();
 
         // Wait for boot hart to complete SBI initialization.
         while !SBI_READY.load(Ordering::Relaxed) {
             core::hint::spin_loop()
         }
+
+        platform::set_pmp();
     }
 
     // Clear all pending IPIs.
@@ -240,7 +224,7 @@ unsafe extern "C" fn relocation_update() {
     asm!(
         // Get load offset.
         "   li t0, {START_ADDRESS}",
-        "   lla t1, .text.entry",
+        "   lla t1, sbi_start",
         "   sub t2, t1, t0",
 
         // Foreach rela.dyn and update relocation.

prototyper/src/platform/mod.rs

@@ -3,6 +3,7 @@ pub mod dynamic;
 #[cfg(feature = "payload")]
 pub mod payload;
 
+use core::arch::asm;
 use riscv::register::mstatus;
 
 pub struct BootInfo {
@@ -19,3 +20,22 @@ pub struct BootHart {
 pub use dynamic::{get_boot_hart, get_boot_info};
 #[cfg(feature = "payload")]
 pub use payload::{get_boot_hart, get_boot_info};
+
+pub fn set_pmp() {
+    // TODO: PMP configuration needs to be obtained through the memory range in the device tree
+    unsafe {
+        use riscv::register::*;
+        let mut sbi_start_address: usize;
+        let mut sbi_end_address: usize;
+        asm!("la {}, sbi_start", out(reg) sbi_start_address, options(nomem));
+        asm!("la {}, sbi_end", out(reg) sbi_end_address, options(nomem));
+        pmpcfg0::set_pmp(0, Range::OFF, Permission::NONE, false);
+        pmpaddr0::write(0);
+        pmpcfg0::set_pmp(1, Range::TOR, Permission::RWX, false);
+        pmpaddr1::write(sbi_start_address);
+        pmpcfg0::set_pmp(2, Range::TOR, Permission::NONE, false);
+        pmpaddr2::write(sbi_end_address);
+        pmpcfg0::set_pmp(3, Range::TOR, Permission::RWX, false);
+        pmpaddr3::write(usize::MAX >> 2);
+    }
+}