add .stack section. clear bss

kernel/src/arch/riscv32/boot/entry.asm

@@ -10,7 +10,7 @@ _start:
 
     call rust_main
 
-    .section .bss
+    .section .bss.stack
     .align 12  #PGSHIFT
     .global bootstack
 bootstack:

kernel/src/arch/riscv32/boot/linker.ld

@@ -22,14 +22,14 @@ SECTIONS
     .text : {
         stext = .;
         *(.text.entry)
-        *(.text .stub .text.* .gnu.linkonce.t.*)
+        *(.text .text.*)
         . = ALIGN(4K);
         etext = .;
     }
 
     .rodata : {
         srodata = .;
-        *(.rodata .rodata.* .gnu.linkonce.r.*)
+        *(.rodata .rodata.*)
         . = ALIGN(4K);
         erodata = .;
     }
@@ -37,21 +37,18 @@ SECTIONS
     .data : {
         sdata = .;
         *(.data .data.*)
-        . = ALIGN(4K);
         edata = .;
     }
 
+    .stack : {
+        *(.bss.stack)
+    }
+
     .bss : {
         sbss = .;
-        *(.bss .bss.* .sbss*)
-        . = ALIGN(4K);
+        *(.bss .bss.*)
         ebss = .;
     }
 
-    .got : {
-        *(.got .got.*)
-        . = ALIGN(4K);
-    }
-
     PROVIDE(end = .);
 }

kernel/src/arch/riscv32/boot/linker64.ld

@@ -32,14 +32,16 @@ SECTIONS
     .data : {
         sdata = .;
         *(.data .data.*)
-        . = ALIGN(4K);
         edata = .;
     }
 
+    .stack : {
+        *(.bss.stack)
+    }
+
     .bss : {
         sbss = .;
         *(.bss .bss.*)
-        . = ALIGN(4K);
         ebss = .;
     }
 

kernel/src/arch/riscv32/memory.rs

@@ -82,6 +82,7 @@ fn remap_the_kernel() {
     ms.push(MemoryArea::new_identity(stext as usize, etext as usize, MemoryAttr::default().execute().readonly(), "text"));
     ms.push(MemoryArea::new_identity(sdata as usize, edata as usize, MemoryAttr::default(), "data"));
     ms.push(MemoryArea::new_identity(srodata as usize, erodata as usize, MemoryAttr::default().readonly(), "rodata"));
+    ms.push(MemoryArea::new_identity(bootstack as usize, bootstacktop as usize, MemoryAttr::default(), "stack"));
     ms.push(MemoryArea::new_identity(sbss as usize, ebss as usize, MemoryAttr::default(), "bss"));
     unsafe { ms.activate(); }
     unsafe { SATP = ms.token(); }
@@ -93,6 +94,14 @@ fn remap_the_kernel() {
 // Other cores load it later.
 static mut SATP: usize = 0;
 
+pub unsafe fn clear_bss() {
+    let bss_start = sbss as usize;
+    let bss_end = ebss as usize;
+    for i in bss_start..bss_end {
+        (i as *mut u8).write(0);
+    }
+}
+
 // Symbols provided by linker script
 extern {
     fn stext();

kernel/src/arch/riscv32/mod.rs

@@ -10,15 +10,19 @@ pub mod cpu;
 #[no_mangle]
 pub extern fn rust_main(hartid: usize, dtb: usize, hart_mask: usize, functions: usize) -> ! {
     unsafe { cpu::set_cpu_id(hartid); }
-    unsafe { BBL_FUNCTIONS_PTR = functions as *const _; }
-    println!("Hello RISCV! in hart {}, dtb @ {:#x}, functions @ {:#x}", hartid, dtb, functions);
 
     if hartid != 0 {
         while unsafe { !cpu::has_started(hartid) }  { }
+        println!("Hello RISCV! in hart {}, dtb @ {:#x}, functions @ {:#x}", hartid, dtb, functions);
         others_main();
         unreachable!();
     }
 
+    unsafe { memory::clear_bss(); }
+    unsafe { BBL_FUNCTIONS_PTR = functions as *const _; }
+
+    println!("Hello RISCV! in hart {}, dtb @ {:#x}, functions @ {:#x}", hartid, dtb, functions);
+
     crate::logging::init();
     interrupt::init();
     memory::init();