add basic exception model and context switching for aarch64

[lunaix-os.git] / lunaix-os / arch / aarch64 / exception / context.S

diff --git a/lunaix-os/arch/aarch64/exception/context.S b/lunaix-os/arch/aarch64/exception/context.S
new file mode 100644 (file)
index 0000000..cbb7cf4
--- /dev/null
+++ b/lunaix-os/arch/aarch64/exception/context.S
@@ -0,0 +1,83 @@
+#define __ASM__
+#include <asm/aa64_msrs.h>
+#include "hart_field.inc"
+
+.section .text
+    
+    .globl _aa64_evec_prehandle
+    .globl _aa64_switch_task
+
+    _aa64_evec_prehandle:
+        stp  xzr, elr, [sp, #-16]!  # push {xzr , elr}
+        stp spsr, xzr, [sp, #-16]!  # push {spsr, xzr}
+
+        stp   lr,  fp, [sp, #-16]!  # push {x31-x1}
+        stp  x28, x27, [sp, #-16]!
+        stp  x26, x25, [sp, #-16]!
+        stp  x24, x23, [sp, #-16]!
+        stp  x22, x21, [sp, #-16]!
+        stp  x20, x19, [sp, #-16]!
+        stp  x18, x17, [sp, #-16]!
+        stp  x16, x15, [sp, #-16]!
+        stp  x14, x13, [sp, #-16]!
+        stp  x12, x11, [sp, #-16]!
+        stp  x10,  x9, [sp, #-16]!
+        stp   x8,  x7, [sp, #-16]!
+        stp   x6,  x5, [sp, #-16]!
+        stp   x4,  x3, [sp, #-16]!
+        stp   x2,  x1, [sp, #-16]!
+        stp   x0, xzr, [sp, #-16]!  # push {x0, xzr}
+
+        add   x1, sp,  #hart_execp
+
+        mrs   x0, SP_EL0
+        str   x0, [x1, #execp_spel0_saved]
+        
+        sub   x0, sp,  #hart_end
+        str   x0, [x1, #execp_spel1_saved]
+        
+        mov   x0, sp
+        bl    handle_exception
+        
+    do_eret:
+        mov   sp,   x0
+
+        add   x1,   x0, #hart_execp
+
+        ldr   x0,  [x1, #execp_spsr]
+        msr   SPSR_EL1, x0
+
+        ldr   x0,  [x1, #execp_link]
+        msr   ELR_E1,   x0
+
+        ldr   x0,  [x1, #execp_spel0_saved]
+        msr   SP_EL0,   x0
+
+        add   sp,  sp, #hart_regs
+
+        ldr   x0,      [sp, #8 ]!
+        ldp   x1,  x2, [sp, #16]!
+        ldp   x3,  x4, [sp, #16]!
+        ldp   x5,  x6, [sp, #16]!
+        ldp   x7,  x8, [sp, #16]!
+        ldp   x9, x10, [sp, #16]!
+        ldp  x11, x12, [sp, #16]!
+        ldp  x13, x14, [sp, #16]!
+        ldp  x15, x16, [sp, #16]!
+        ldp  x17, x18, [sp, #16]!
+        ldp  x19, x20, [sp, #16]!
+        ldp  x21, x22, [sp, #16]!
+        ldp  x23, x24, [sp, #16]!
+        ldp  x25, x26, [sp, #16]!
+        ldp  x27, x28, [sp, #16]!
+        ldp   fp,  lr, [sp, #16]!
+        
+        # sp now point to the start of exec_param
+
+        ldr   sp,  [sp, #execp_spel1_saved]
+
+        eret
+
+    _aa64_switch_task:
+        # TODO
+        b     do_eret
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