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-rw-r--r--src/arch/arm64/include/armv8/arch/cpu.h6
-rw-r--r--src/arch/arm64/stage_entry.S79
2 files changed, 63 insertions, 22 deletions
diff --git a/src/arch/arm64/include/armv8/arch/cpu.h b/src/arch/arm64/include/armv8/arch/cpu.h
index 70311dd194..e80e739133 100644
--- a/src/arch/arm64/include/armv8/arch/cpu.h
+++ b/src/arch/arm64/include/armv8/arch/cpu.h
@@ -52,4 +52,10 @@ struct cpu_info *cpu_info(void);
*/
unsigned int smp_processor_id(void);
+/* Return the top of the stack for the specified cpu. */
+void *cpu_get_stack(unsigned int cpu);
+
+/* Return the top of the exception stack for the specified cpu. */
+void *cpu_get_exception_stack(unsigned int cpu);
+
#endif /* __ARCH_CPU_H__ */
diff --git a/src/arch/arm64/stage_entry.S b/src/arch/arm64/stage_entry.S
index 2d4b26dac9..1de8894f2a 100644
--- a/src/arch/arm64/stage_entry.S
+++ b/src/arch/arm64/stage_entry.S
@@ -30,13 +30,58 @@
#error Need to know what ELx processor starts up in.
#endif
+#define STACK_SZ CONFIG_STACK_SIZE
+#define EXCEPTION_STACK_SZ CONFIG_STACK_SIZE
+
+/*
+ * The stacks for each of the armv8 cores grows down from _estack. It is sized
+ * according to MAX_CPUS. Additionally provide exception stacks for each CPU.
+ */
+.section .bss, "aw", @nobits
+.global _stack
+.global _estack
+.balign STACK_SZ
+_stack:
+.space CONFIG_MAX_CPUS*STACK_SZ
+_estack:
+
+.global _stack_exceptions
+.global _estack_exceptions
+.balign EXCEPTION_STACK_SZ
+_stack_exceptions:
+.space CONFIG_MAX_CPUS*EXCEPTION_STACK_SZ
+_estack_exceptions:
+
+ENTRY(cpu_get_stack)
+ mov x1, #STACK_SZ
+ mul x0, x0, x1
+ ldr x1, 1f
+ sub x0, x1, x0
+ ret
+.align 3
+1:
+ .quad _estack
+ENDPROC(cpu_get_stack)
+
+ENTRY(cpu_get_exception_stack)
+ mov x1, #EXCEPTION_STACK_SZ
+ mul x0, x0, x1
+ ldr x1, 1f
+ sub x0, x1, x0
+ ret
+.align 3
+1:
+ .quad _estack_exceptions
+ENDPROC(cpu_get_exception_stack)
+
+
ENTRY(seed_stack)
/*
* Initialize the stack to a known value. This is used to check for
* stack overflow later in the boot process.
*/
ldr x0, .stack_bottom
- ldr x1, .stack_top
+ mov x1, sp
ldr x2, =0xdeadbeefdeadbeef
ldr x3, =0x8
@@ -59,36 +104,26 @@ ENDPROC(seed_stack)
* stack while keeping SP_ELx reserved for exception entry.
*/
ENTRY(arm64_c_environment)
- ldr x0, .exception_stack_top
- cmp x0, #0
- b.eq 2f
+ bl smp_processor_id /* x0 = cpu */
+ mov x24, x0
+
+
+ /* Set the exception stack for this cpu. */
+ bl cpu_get_exception_stack
msr SPSel, #1
isb
-
mov sp, x0
- 2:
/* Have stack pointer use SP_EL0. */
msr SPSel, #0
isb
- /* Load up the stack if non-zero. */
- ldr x0, .stack_top
- cmp x0, #0
- b.eq 1f
+ /* Set stack for this cpu. */
+ mov x0, x24 /* x0 = cpu */
+ bl cpu_get_stack
mov sp, x0
- 1:
-
- ldr x1, .entry
- br x1
-
- .align 4
- .exception_stack_top:
- .quad CONFIG_EXCEPTION_STACK_TOP
- .stack_top:
- .quad _estack
- .entry:
- .quad seed_stack
+
+ b seed_stack
ENDPROC(arm64_c_environment)
CPU_RESET_ENTRY(arm64_cpu_startup)