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| <h5 class="subsubsection">9.4.2.4 ARM relocation generation</h5> |
| |
| <p><a name="index-data-relocations_002c-ARM-760"></a><a name="index-ARM-data-relocations-761"></a>Specific data relocations can be generated by putting the relocation name |
| in parentheses after the symbol name. For example: |
| |
| <pre class="smallexample"> .word foo(TARGET1) |
| </pre> |
| <p>This will generate an ‘<samp><span class="samp">R_ARM_TARGET1</span></samp>’ relocation against the symbol |
| <var>foo</var>. |
| The following relocations are supported: |
| <code>GOT</code>, |
| <code>GOTOFF</code>, |
| <code>TARGET1</code>, |
| <code>TARGET2</code>, |
| <code>SBREL</code>, |
| <code>TLSGD</code>, |
| <code>TLSLDM</code>, |
| <code>TLSLDO</code>, |
| <code>TLSDESC</code>, |
| <code>TLSCALL</code>, |
| <code>GOTTPOFF</code>, |
| <code>GOT_PREL</code> |
| and |
| <code>TPOFF</code>. |
| |
| <p>For compatibility with older toolchains the assembler also accepts |
| <code>(PLT)</code> after branch targets. On legacy targets this will |
| generate the deprecated ‘<samp><span class="samp">R_ARM_PLT32</span></samp>’ relocation. On EABI |
| targets it will encode either the ‘<samp><span class="samp">R_ARM_CALL</span></samp>’ or |
| ‘<samp><span class="samp">R_ARM_JUMP24</span></samp>’ relocation, as appropriate. |
| |
| <p><a name="index-MOVW-and-MOVT-relocations_002c-ARM-762"></a>Relocations for ‘<samp><span class="samp">MOVW</span></samp>’ and ‘<samp><span class="samp">MOVT</span></samp>’ instructions can be generated |
| by prefixing the value with ‘<samp><span class="samp">#:lower16:</span></samp>’ and ‘<samp><span class="samp">#:upper16</span></samp>’ |
| respectively. For example to load the 32-bit address of foo into r0: |
| |
| <pre class="smallexample"> MOVW r0, #:lower16:foo |
| MOVT r0, #:upper16:foo |
| </pre> |
| <p>Relocations ‘<samp><span class="samp">R_ARM_THM_ALU_ABS_G0_NC</span></samp>’, ‘<samp><span class="samp">R_ARM_THM_ALU_ABS_G1_NC</span></samp>’, |
| ‘<samp><span class="samp">R_ARM_THM_ALU_ABS_G2_NC</span></samp>’ and ‘<samp><span class="samp">R_ARM_THM_ALU_ABS_G3_NC</span></samp>’ can be |
| generated by prefixing the value with ‘<samp><span class="samp">#:lower0_7:#</span></samp>’, |
| ‘<samp><span class="samp">#:lower8_15:#</span></samp>’, ‘<samp><span class="samp">#:upper0_7:#</span></samp>’ and ‘<samp><span class="samp">#:upper8_15:#</span></samp>’ |
| respectively. For example to load the 32-bit address of foo into r0: |
| |
| <pre class="smallexample"> MOVS r0, #:upper8_15:#foo |
| LSLS r0, r0, #8 |
| ADDS r0, #:upper0_7:#foo |
| LSLS r0, r0, #8 |
| ADDS r0, #:lower8_15:#foo |
| LSLS r0, r0, #8 |
| ADDS r0, #:lower0_7:#foo |
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