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https://github.com/CloverHackyColor/CloverBootloader.git
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46 lines
1.0 KiB
ArmAsm
46 lines
1.0 KiB
ArmAsm
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//
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// Copyright (c) 2012 - 2020, ARM Limited. All rights reserved.
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//
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// SPDX-License-Identifier: BSD-2-Clause-Patent
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//
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//
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.text
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.align 3
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GCC_ASM_EXPORT(ArmCallSvc)
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ASM_PFX(ArmCallSvc):
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// Push frame pointer and return address on the stack
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stp x29, x30, [sp, #-32]!
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mov x29, sp
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// Push x0 on the stack - The stack must always be quad-word aligned
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str x0, [sp, #16]
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// Load the SVC arguments values into the appropriate registers
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ldp x6, x7, [x0, #48]
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ldp x4, x5, [x0, #32]
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ldp x2, x3, [x0, #16]
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ldp x0, x1, [x0, #0]
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svc #0
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// Prevent speculative execution beyond svc instruction
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dsb nsh
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isb
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// Pop the ARM_SVC_ARGS structure address from the stack into x9
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ldr x9, [sp, #16]
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// Store the SVC returned values into the ARM_SVC_ARGS structure.
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// A SVC call can return up to 8 values
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stp x0, x1, [x9, #0]
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stp x2, x3, [x9, #16]
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stp x4, x5, [x9, #32]
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stp x6, x7, [x9, #48]
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mov x0, x9
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ldp x29, x30, [sp], #32
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ret
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