72d98d16ed
To support thumb1 execute-only code we need to support four new relocations (R_ARM_THM_ALU_ABS_G0_NC, R_ARM_THM_ALU_ABS_G1_NC, R_ARM_THM_ALU_ABS_G2_NC and R_ARM_THM_ALU_ABS_G3_NC). These relocations allow the static linker to finalize construction of symbol address. Typical sequence of code to get address of the symbol foo is then the following : movs r3, #:upper8_15:#foo lsls r3, #8 adds r3, #:upper0_7:#foo lsls r3, #8 adds r3, #:lower8_15:#foo lsls r3, #8 adds r3, #:lower0_7:#foo This will give following sequence of text and relocations after assembly : 4: 2300 movs r3, #0 4: R_ARM_THM_ALU_ABS_G3_NC foo 6: 021b lsls r3, r3, #8 8: 3300 adds r3, #0 8: R_ARM_THM_ALU_ABS_G2_NC foo a: 021b lsls r3, r3, #8 c: 3300 adds r3, #0 c: R_ARM_THM_ALU_ABS_G1_NC foo e: 021b lsls r3, r3, #8 10: 3300 adds r3, #0 10: R_ARM_THM_ALU_ABS_G0_NC foo
43 lines
925 B
ArmAsm
43 lines
925 B
ArmAsm
.text
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.arch armv6s-m
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.syntax unified
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.global _start
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.thumb_func
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.type _start, %function
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_start:
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.thumb_func
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.type thumb1, %function
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thumb1:
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adds r0, #:upper8_15:#thumb3
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adds r1, #:upper0_7:#thumb3
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adds r2, #:lower8_15:#thumb1
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adds r3, #:lower0_7:#thumb1
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adds r4, #:lower0_7:#thumb3
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adds r5, #:lower8_15:#thumb3
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adds r6, #:upper0_7:#thumb1
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adds r7, #:upper8_15:#thumb1
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.thumb_func
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.type thumb2, %function
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thumb2:
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adds r0, #:upper8_15:#thumb3
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adds r1, #:upper0_7:#(var2 + 1)
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adds r2, #:lower8_15:#(thumb3 + 255)
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adds r3, #:lower0_7:#(var1 + 0xaa)
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adds r7, #:upper8_15:#var1 + 4
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adds r6, #:upper0_7:#thumb3
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adds r5, #:lower8_15:#var2 + 0xff
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adds r4, #:lower0_7:#var2 - (-2)
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var1:
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.byte 1
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var2:
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.byte 2
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.section .far, "ax", %progbits
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.thumb_func
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.type thumb3, %function
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thumb3:
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adds r0, #:upper8_15:#thumb1
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adds r1, #:upper0_7:#thumb2
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adds r2, #:lower8_15:#thumb3
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adds r3, #:lower0_7:#thumb1
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