x86/{boot,cpu}: dynamically allocate AP boot stacks

The main goal of this change is to reduce the size of the kernel
executable image since boot stacks, despite being uninitialized,
aren't declared as common symbols.

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/x86/machine/cpu.h b/arch/x86/machine/cpu.h
index 97ef8ef1..f1e9cfb6 100644
--- a/arch/x86/machine/cpu.h
+++ b/arch/x86/machine/cpu.h
@@ -254,6 +254,7 @@ struct cpu {
     struct cpu_tss double_fault_tss;
 #endif /* __LP64__ */
     volatile int state;
+    unsigned long boot_stack;
     unsigned long double_fault_stack;
 } __aligned(CPU_ALIGN);
 
@@ -583,6 +584,11 @@ cpu_delay(unsigned long usecs)
 }
 
 /*
+ * Return the address of the boot stack allocated for the current processor.
+ */
+unsigned long cpu_get_boot_stack(void);
+
+/*
  * Set the given GDT for the current processor, and reload its segment
  * registers.
  */