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-rw-r--r--lib/mlibc/options/rtdl/aarch64/runtime.S62
1 files changed, 62 insertions, 0 deletions
diff --git a/lib/mlibc/options/rtdl/aarch64/runtime.S b/lib/mlibc/options/rtdl/aarch64/runtime.S
new file mode 100644
index 0000000..c3e2cff
--- /dev/null
+++ b/lib/mlibc/options/rtdl/aarch64/runtime.S
@@ -0,0 +1,62 @@
+
+.global __mlibcTlsdescStatic
+.hidden __mlibcTlsdescStatic
+.type __mlibcTlsdescStatic,@function
+__mlibcTlsdescStatic:
+ ldr x0, [x0, #8]
+ ret
+
+// This function depends on the Tcb layout, since it pulls out the dtv pointer
+// out of the thread control block
+.global __mlibcTlsdescDynamic
+.hidden __mlibcTlsdescDynamic
+.type __mlibcTlsdescDynamic,@function
+__mlibcTlsdescDynamic:
+ stp x1, x2, [sp, #-16]!
+ ldr x0, [x0, #8]
+ ldp x1, x2, [x0] // tlsIndex, addend
+ mrs x0, tpidr_el0 // tp
+ ldr x0, [x0, #-104] // tp->dtvPointers
+ ldr x0, [x0, x1, lsl 3] // [tlsIndex]
+ add x0, x0, x2 // + addend
+ mrs x1, tpidr_el0 // tp
+ sub x0, x0, x1 // result - tp
+ ldp x1, x2, [sp], #16
+ ret
+
+.global pltRelocateStub
+pltRelocateStub:
+ // we need to save / restore all registers than can hold function arguments
+ // we do not need to save callee-saved registers as they will not be trashed by lazyRelocate
+ // TODO: save floating point argument registers
+
+ stp x0, x1, [sp, #-16]!
+
+ // pointer to PLT entry
+ ldr x1, [sp, #24]
+ ldr x0, [x16]
+ sub x1, x1, x0
+ asr x0, x0, #3
+
+ // pointer GOT
+ sub x0, x16, #8 // &PLTGOT[1]
+
+ stp x2, x3, [sp, #-16]!
+ stp x4, x5, [sp, #-16]!
+ stp x6, x7, [sp, #-16]!
+ stp x8, x30, [sp, #-16]!
+
+ bl lazyRelocate
+ mov x9, x0
+
+ ldp x8, x30, [sp], #16
+ ldp x6, x7, [sp], #16
+ ldp x4, x5, [sp], #16
+ ldp x2, x1, [sp], #16
+
+ ldp x0, x1, [sp], #16
+ add sp, sp, #16
+ br x9
+
+.section .note.GNU-stack,"",%progbits
+