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BL51 User's Guide

BL51 Introduction Linking Programs Locating Segments Data Overlaying Code Banking Real-Time Programs Error Messages Warning L1 Warning L2 Warning L3 Warning L4 Warning L5 Warning L6 Warning L7 Warning L8 Warning L9 Warning L10 Warning L11 Warning L12 Warning L13 Warning L14 Warning L15 Warning L16 Warning L17 Warning L18 Warning L19 Warning L20 Warning L21 Warning L22 Warning L23 Warning L24 Warning L25 Warning L26 Warning L27 Warning L28 Warning L29 Warning L30 Warning L31 Warning L32 Warning L33 Warning L34 Warning L35 Warning L36 Warning L37 Warning L38 Warning L40 Warning L41 Warning L42 Warning L43 Warning L44 Warning L45 Warning L46 Warning L47 Warning L48 Warning L49 Warning L50 Warning L51 Warning L52 Warning L54 Warning L55 Warning L56 Warning L57 Warning L58 Error L101 Error L102 Error L103 Error L104 Error L105 Error L106 Error L107 Error L108 Error L109 Error L110 Error L111 Error L112 Error L113 Error L114 Error L115 Error L116 Error L117 Error L118 Error L119 Error L120 Error L121 Error L122 Error L123 Error L124 Error L125 Error L126 Error L127 Error L128 Error L129 Error L130 Error L131 Error L132 Error L133 Error L134 Error L135 Error L136 Error L137 Error L138 Error L139 Error L140 Error L141 Error L142 Error L143 Error L144 Fatal Error L201 Fatal Error L202 Fatal Error L203 Fatal Error L204 Fatal Error L205 Fatal Error L206 Fatal Error L207 Fatal Error L208 Fatal Error L209 Fatal Error L210 Fatal Error L211 Fatal Error L212 Fatal Error L213 Fatal Error L214 Fatal Error L215 Fatal Error L216 Fatal Error L217 Fatal Error L218 Fatal Error L219 Fatal Error L220 Fatal Error L221 Fatal Error L222 Fatal Error L224 Fatal Error L225 Fatal Error L226 Fatal Error L227 Fatal Error L228 Fatal Error L229 Fatal Error L230 Fatal Error L231 Fatal Error L232 Fatal Error L233 Fatal Error L234 Fatal Error L235 Fatal Error L236 Fatal Error L237 Fatal Error L238 Fatal Error L239 Fatal Error L240 Fatal Error L241 Fatal Error L242 Fatal Error L243 Fatal Error L244 Fatal Error L245 Fatal Error L246 Fatal Error L247 Fatal Error L248 Fatal Error L249 Fatal Error L250 Fatal Error L251 Fatal Error L254 Fatal Error L255 Fatal Error L256 Fatal Error L257 Fatal Error L258

Warning L10

*** Warning L10

Cannot Determine Root Segment


While processing the input object modules, the linker determined that overlay analysis is required (this is typically the case with object modules created using the C51 or PL/M-51 Compilers). However, the linker was unable to determine the root segment (which is required for overlay analysis).


This is usually caused by a program with mixed C and assembly where:

  • The original Keil startup code is not used,
  • or the main C function is not used,
  • or only C functions are used and called by a main assembly function.

Without changing the structure of the program, there are two solutions to this problem.

  1. Use the NOOVERLAY directive to disable overlay analysis entirely.
  2. Use the OVERLAY directive to create references between the appropriate program functions.

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