Only keep _start in the .text section to fix #25 (#26)

* [platforms] only keep `_start` in `.text` section

Specifically, it moves `_start_primary` and `_start_secondary` from the
`.text.boot` section to the `.text` section to prevent the linker from
placing them before `_start`.

Fix #25

* [chore] fix cargo build warnings

* fix: replace `doc_auto_cfg` with `doc_cfg`

See rust-lang/rust#138907

* chore: remove `link_section = ".text"`

---------

Co-authored-by: 朝倉水希 <[email protected]>

Author: equation314

axplat/src/lib.rs

@@ -1,5 +1,5 @@
 #![cfg_attr(not(test), no_std)]
-#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
 #![doc = include_str!("../README.md")]
 
 #[macro_use]

platforms/axplat-aarch64-bsta1000b/src/boot.rs

@@ -79,7 +79,6 @@ unsafe extern "C" fn _start() -> ! {
 
 /// The earliest entry point for the primary CPU.
 #[unsafe(naked)]
-#[unsafe(link_section = ".text.boot")]
 unsafe extern "C" fn _start_primary() -> ! {
     // X0 = dtb
     core::arch::naked_asm!("
@@ -120,7 +119,6 @@ unsafe extern "C" fn _start_primary() -> ! {
 /// The earliest entry point for the secondary CPUs.
 #[cfg(feature = "smp")]
 #[unsafe(naked)]
-#[unsafe(link_section = ".text.boot")]
 pub(crate) unsafe extern "C" fn _start_secondary() -> ! {
     // X0 = stack pointer
     core::arch::naked_asm!("

platforms/axplat-aarch64-bsta1000b/src/mp.rs

@@ -8,7 +8,7 @@ pub fn start_secondary_cpu(cpu_id: usize, stack_top: PhysAddr) {
         return;
     }
 
-    let entry = virt_to_phys(va!(crate::boot::_start_secondary as usize));
+    let entry = virt_to_phys(va!(crate::boot::_start_secondary as *const () as usize));
     axplat_aarch64_peripherals::psci::cpu_on(
         CPU_ID_LIST[cpu_id],
         entry.as_usize(),

platforms/axplat-aarch64-phytium-pi/src/boot.rs

@@ -80,7 +80,6 @@ unsafe extern "C" fn _start() -> ! {
 
 /// The earliest entry point for the primary CPU.
 #[unsafe(naked)]
-#[unsafe(link_section = ".text.boot")]
 unsafe extern "C" fn _start_primary() -> ! {
     // X0 = dtb
     core::arch::naked_asm!("
@@ -123,7 +122,6 @@ unsafe extern "C" fn _start_primary() -> ! {
 /// The earliest entry point for the secondary CPUs.
 #[cfg(feature = "smp")]
 #[unsafe(naked)]
-#[unsafe(link_section = ".text.boot")]
 pub(crate) unsafe extern "C" fn _start_secondary() -> ! {
     // X0 = stack pointer
     core::arch::naked_asm!("

platforms/axplat-aarch64-phytium-pi/src/power.rs

@@ -14,7 +14,7 @@ impl PowerIf for PowerImpl {
         use crate::config::plat::CPU_ID_LIST;
         use axplat::mem::{va, virt_to_phys};
 
-        let entry = virt_to_phys(va!(crate::boot::_start_secondary as usize));
+        let entry = virt_to_phys(va!(crate::boot::_start_secondary as *const () as usize));
         axplat_aarch64_peripherals::psci::cpu_on(
             CPU_ID_LIST[cpu_id],
             entry.as_usize(),

platforms/axplat-aarch64-qemu-virt/src/boot.rs

@@ -73,7 +73,6 @@ unsafe extern "C" fn _start() -> ! {
 
 /// The earliest entry point for the primary CPU.
 #[unsafe(naked)]
-#[unsafe(link_section = ".text.boot")]
 unsafe extern "C" fn _start_primary() -> ! {
     // X0 = dtb
     core::arch::naked_asm!("
@@ -114,7 +113,6 @@ unsafe extern "C" fn _start_primary() -> ! {
 /// The earliest entry point for the secondary CPUs.
 #[cfg(feature = "smp")]
 #[unsafe(naked)]
-#[unsafe(link_section = ".text.boot")]
 pub(crate) unsafe extern "C" fn _start_secondary() -> ! {
     // X0 = stack pointer
     core::arch::naked_asm!("

platforms/axplat-aarch64-qemu-virt/src/power.rs

@@ -12,7 +12,7 @@ impl PowerIf for PowerImpl {
     #[cfg(feature = "smp")]
     fn cpu_boot(cpu_id: usize, stack_top_paddr: usize) {
         use axplat::mem::{va, virt_to_phys};
-        let entry_paddr = virt_to_phys(va!(crate::boot::_start_secondary as usize));
+        let entry_paddr = virt_to_phys(va!(crate::boot::_start_secondary as *const () as usize));
         axplat_aarch64_peripherals::psci::cpu_on(cpu_id, entry_paddr.as_usize(), stack_top_paddr);
     }
 

platforms/axplat-aarch64-raspi/src/boot.rs

@@ -95,7 +95,6 @@ unsafe extern "C" fn _start() -> ! {
 /// The earliest entry point for the secondary CPUs.
 #[cfg(feature = "smp")]
 #[unsafe(naked)]
-#[unsafe(link_section = ".text.boot")]
 pub(crate) unsafe extern "C" fn _start_secondary() -> ! {
     // X0 = stack pointer
     core::arch::naked_asm!("

platforms/axplat-loongarch64-qemu-virt/src/boot.rs

@@ -92,7 +92,6 @@ unsafe extern "C" fn _start() -> ! {
 #[cfg(feature = "smp")]
 #[unsafe(naked)]
 #[unsafe(no_mangle)]
-#[unsafe(link_section = ".text.boot")]
 unsafe extern "C" fn _start_secondary() -> ! {
     core::arch::naked_asm!("
         ori          $t0, $zero, 0x1     # CSR_DMW1_PLV0

platforms/axplat-loongarch64-qemu-virt/src/mp.rs

@@ -16,6 +16,6 @@ pub fn start_secondary_cpu(cpu_id: usize, stack_top: PhysAddr) {
     unsafe {
         SMP_BOOT_STACK_TOP = stack_top_virt_addr;
     }
-    csr_mail_send(_start_secondary as usize as _, cpu_id, 0);
+    csr_mail_send(_start_secondary as *const () as _, cpu_id, 0);
     send_ipi_single(cpu_id, ACTION_BOOT_CPU);
 }