37 lines
1.2 KiB
ReStructuredText
37 lines
1.2 KiB
ReStructuredText
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Assembler Directives
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====================
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Labels
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------
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* label(INNER1)
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This defines a label for use in a branch instruction. Thus elsewhere in the code a ``b(INNER1)``
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will cause execution to continue with the instruction after the label directive.
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Defining inline data
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--------------------
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The following assembler directives facilitate embedding data in an assembler code block.
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* data(size, d0, d1 .. dn)
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The data directive creates n array of data values in memory. The first argument specifies the
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size in bytes of the subsequent arguments. Hence the first statement below will cause the
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assembler to put three bytes (with values 2, 3 and 4) into consecutive memory locations
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while the second will cause it to emit two four byte words.
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::
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data(1, 2, 3, 4)
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data(4, 2, 100000)
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Data values longer than a single byte are stored in memory in little-endian format.
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* align(nBytes)
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Align the following instruction to an nBytes value. ARM Thumb-2 instructions must be two
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byte aligned, hence it's advisable to issue ``align(2)`` after ``data`` directives and
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prior to any subsequent code. This ensures that the code will run irrespective of the
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size of the data array.
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