[SOLVED] create system unit from scratch
lazarus / 64-FPC development

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Key-Real · 2024-04-18 11:01

I looked at other implementation and the first thing all do is to
include systemh.inc, so i do the same:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i unit
system;{$MODE FPC}interface {$I systemh.inc} implementationend.

but this gives me:



Compiling ./rtl/ps1/system.pp
systemh.inc(23,2) Error: Mode switch "OBJFPC" not allowed here
filerec.inc(33,17) Error: Identifier not found "THandle"
filerec.inc(33,24) Error: Error in type definition
textrec.inc(38,17) Error: Identifier not found "THandle"
textrec.inc(38,24) Error: Error in type definition
systemh.inc(867,17) Error: Identifier not found "TThreadID"
systemh.inc(867,26) Error: Error in type definition
mathh.inc(200,53) Fatal: Syntax error, ")" expected but "=" found
Fatal: Compilation aborted

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Key-Real · 2024-04-18 11:14

OK, I can't define {$MODE FPC}

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Laksen · 2024-04-18 11:28

Those missing types are defined a platform specific sysosh.inc

For something like the PS1 maybe take a look at how the embedded
platform structures the system unit and the sys*.inc contents

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KodeZwerg · 2024-04-18 12:02

To compare it with a hospital, you are currently doing a heart
transplantation and you just cut off every connection.
So be a good surgeon and put back the missing parts or the heart stay
dead.

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Key-Real · 2024-04-19 08:34

I gonna implement only the minimal requered code in the system unit

pls explain what  type

1)  jmp_buf
2) TExceptAddr
3) TGuid

do and what is minimal implementation of thouse.

I found https://wiki.lazarus.freepascal.org/System_unit

but there is no detailed explanation

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Laksen · 2024-04-19 08:53

jmp_buf is a record used to store the state of the CPU for the setjmp
and longjmp procedures. This functionality is used for exception
handling. They are already implemented for MIPS in
rtl/mips/setjump*.inc which is included by systemh.inc

TExceptAddr is as the name hints also used for exception handling and
implemented in a generic way shared by all the targets in excepth.inc
included by systemh.inc
TGuid stores a GUID. The compiler needs to point to it during
compilation when GUIDs are needed. Also implemented in a generic
manner in objpash.inc included by systemh.inc


The key to implementing a systems unit is to get the proper defines,
paths and system specific dummy functionality (usually residese in
sys*/tthread/check.inc files) implemented. There's no documentation
but you should see how other system units are structured