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annotate doc/manual/x35.html @ 442:a9521955554f 3.0
Added pragma pcaspcr to treat PC as PCR; additional fixes for PCR addressing modes
| author | lost@l-w.ca |
|---|---|
| date | Sat, 30 Oct 2010 12:15:00 -0600 |
| parents | b8bf63962a99 |
| children |
| rev | line source |
|---|---|
| 434 | 1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd"> |
| 2 <HTML | |
| 3 ><HEAD | |
| 4 ><TITLE | |
| 5 >Object Files</TITLE | |
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| 8 CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK | |
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| 36 ><TR | |
| 37 ><TH | |
| 38 COLSPAN="3" | |
| 39 ALIGN="center" | |
| 40 >LW Tool Chain</TH | |
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| 45 ALIGN="left" | |
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| 50 >Prev</A | |
| 51 ></TD | |
| 52 ><TD | |
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| 56 >Chapter 2. Output Formats</TD | |
| 57 ><TD | |
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| 59 ALIGN="right" | |
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| 72 CLASS="SECTION" | |
| 73 ><H1 | |
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| 75 ><A | |
| 76 NAME="AEN35" | |
| 77 >2.4. Object Files</A | |
| 78 ></H1 | |
| 79 ><P | |
| 80 >LWASM supports generating a proprietary object file format which is | |
| 81 described in <A | |
|
442
a9521955554f
Added pragma pcaspcr to treat PC as PCR; additional fixes for PCR addressing modes
lost@l-w.ca
parents:
434
diff
changeset
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82 HREF="c839.html" |
| 434 | 83 >Chapter 6</A |
| 84 >. LWLINK is then used to link these | |
| 85 object files into a final binary in any of LWLINK's supported binary | |
| 86 formats.</P | |
| 87 ><P | |
| 88 >Object files also support the concept of sections which are not valid | |
| 89 for other output types. This allows related code from each object file | |
| 90 linked to be collapsed together in the final binary.</P | |
| 91 ><P | |
| 92 >Object files are very flexible in that they allow references that are not | |
| 93 known at assembly time to be resolved at link time. However, because the | |
| 94 addresses of such references are not known at assembly time, there is no way | |
| 95 for the assembler to deduce that an eight bit addressing mode is possible. | |
| 96 That means the assember will default to using sixteen bit addressing | |
| 97 whenever an external or cross-section reference is used.</P | |
| 98 ><P | |
| 99 >As of LWASM 2.4, it is possible to force direct page addressing for an | |
| 100 external reference. Care must be taken to ensure the resulting addresses | |
| 101 are really in the direct page since the linker does not know what the direct | |
| 102 page is supposed to be and does not emit errors for byte overflows.</P | |
| 103 ><P | |
| 104 >It is also possible to use external references in an eight bit immediate | |
| 105 mode instruction. In this case, only the low order eight bits will be used. | |
| 106 Again, no byte overflows will be flagged.</P | |
| 107 ></DIV | |
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