Difference between revisions of "BareMetal"
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== SysTick == | == SysTick == | ||
| + | Some parts of the µGFX library require how much time passed by. For this access to the systems tick counter (SysTick) is required. To give µGFX the ability to calculate how much time passed the following to functions need to be implemented in the users application code: | ||
| + | <syntaxhighlight lang"c"> | ||
| + | systemticks_t gfxSystemTicks(void); | ||
| + | systemticks_t gfxMillisecondsToTicks(delaytime_t ms); | ||
| + | </syntaxhighlight> | ||
| + | The first one, ''gfxSystemTicks()'', needs to return the current value of the systick counter. The second one, ''gfxMillisecondsToTicks()'' needs to convert the provided value in milliseconds to systicks. | ||
| + | |||
| + | === Example === | ||
| + | The following is an example showing how to implement the two functions when using an STM32F4 microcontroller using the STM32Cube HAL. Note that in this case the systick was set up to be incremented once every millisecond. If your systick updates in a different interval you need to do the corresponding calculations in ''gfxMillisecondsToTicks()''. | ||
| + | <syntaxhighlight lang"c"> | ||
| + | #include "gfx.h" | ||
| + | #include "stm32f4xx_hal.h" | ||
| + | |||
| + | systemticks_t gfxSystemTicks(void) | ||
| + | { | ||
| + | return HAL_GetTick(); | ||
| + | } | ||
| + | |||
| + | systemticks_t gfxMillisecondsToTicks(delaytime_t ms) | ||
| + | { | ||
| + | return ms; | ||
| + | } | ||
| + | </syntaxhighlight> | ||
Revision as of 13:48, 3 July 2015
µGFX can run on any system without any underlying OS or RTOS. The RAW32 port provides all the required implementations to run on a bare metal system. The only thing required to implement by the user are two small functions which are used to calculate delays. See SysTick.
Contents
Memory Management
µGFX can run either completely on static memory or on dynamic memory. While the first is very important for security and time critical applications it can be very tedious in generic applications. The RAW32 provides a memory manager to work with dynamic memory on any bare metal system. The following two configuration options are available:
- Use the µGFX built-in memory manager
- Use the C runtime library memory manager
Which one is used depends on the value of GOS_RAW_HEAP_SIZE inside of the configuration file.
Built-in memory manager
When GOS_RAW_HEAP_SIZE is set to a value greater than 0 then the built-in memory manager of µGFX is used. In this case the value of GOS_RAW_HEAP_SIZE specifies the size of the memory pool which the built-in memory manager will use.
C runtime library memory manager
When GOS_RAW_HEAP_SIZE is set to 0 then the memory manager of the C runtime library will be used. In that case gfxAlloc() and gfxFree() are just wrappers around malloc() and free()
SysTick
Some parts of the µGFX library require how much time passed by. For this access to the systems tick counter (SysTick) is required. To give µGFX the ability to calculate how much time passed the following to functions need to be implemented in the users application code:
Invalid language.
You need to specify a language like this: <source lang="html4strict">...</source>
Supported languages for syntax highlighting:
4cs, 6502acme, 6502kickass, 6502tasm, 68000devpac, abap, actionscript, actionscript3, ada, algol68, apache, applescript, apt_sources, arm, asm, asp, asymptote, autoconf, autohotkey, autoit, avisynth, awk, bascomavr, bash, basic4gl, bf, bibtex, blitzbasic, bnf, boo, c, c_loadrunner, c_mac, caddcl, cadlisp, cfdg, cfm, chaiscript, cil, clojure, cmake, cobol, coffeescript, cpp, cpp-qt, csharp, css, cuesheet, d, dcl, dcpu16, dcs, delphi, diff, div, dos, dot, e, ecmascript, eiffel, email, epc, erlang, euphoria, f1, falcon, fo, fortran, freebasic, freeswitch, fsharp, gambas, gdb, genero, genie, gettext, glsl, gml, gnuplot, go, groovy, gwbasic, haskell, haxe, hicest, hq9plus, html4strict, html5, icon, idl, ini, inno, intercal, io, j, java, java5, javascript, jquery, kixtart, klonec, klonecpp, latex, lb, ldif, lisp, llvm, locobasic, logtalk, lolcode, lotusformulas, lotusscript, lscript, lsl2, lua, m68k, magiksf, make, mapbasic, matlab, mirc, mmix, modula2, modula3, mpasm, mxml, mysql, nagios, netrexx, newlisp, nsis, oberon2, objc, objeck, ocaml, ocaml-brief, octave, oobas, oorexx, oracle11, oracle8, oxygene, oz, parasail, parigp, pascal, pcre, per, perl, perl6, pf, php, php-brief, pic16, pike, pixelbender, pli, plsql, postgresql, povray, powerbuilder, powershell, proftpd, progress, prolog, properties, providex, purebasic, pycon, pys60, python, q, qbasic, rails, rebol, reg, rexx, robots, rpmspec, rsplus, ruby, sas, scala, scheme, scilab, sdlbasic, smalltalk, smarty, spark, sparql, sql, stonescript, systemverilog, tcl, teraterm, text, thinbasic, tsql, typoscript, unicon, upc, urbi, uscript, vala, vb, vbnet, vedit, verilog, vhdl, vim, visualfoxpro, visualprolog, whitespace, whois, winbatch, xbasic, xml, xorg_conf, xpp, yaml, z80, zxbasic
systemticks_t gfxSystemTicks(void); systemticks_t gfxMillisecondsToTicks(delaytime_t ms);
The first one, gfxSystemTicks(), needs to return the current value of the systick counter. The second one, gfxMillisecondsToTicks() needs to convert the provided value in milliseconds to systicks.
Example
The following is an example showing how to implement the two functions when using an STM32F4 microcontroller using the STM32Cube HAL. Note that in this case the systick was set up to be incremented once every millisecond. If your systick updates in a different interval you need to do the corresponding calculations in gfxMillisecondsToTicks().
Invalid language.
You need to specify a language like this: <source lang="html4strict">...</source>
Supported languages for syntax highlighting:
4cs, 6502acme, 6502kickass, 6502tasm, 68000devpac, abap, actionscript, actionscript3, ada, algol68, apache, applescript, apt_sources, arm, asm, asp, asymptote, autoconf, autohotkey, autoit, avisynth, awk, bascomavr, bash, basic4gl, bf, bibtex, blitzbasic, bnf, boo, c, c_loadrunner, c_mac, caddcl, cadlisp, cfdg, cfm, chaiscript, cil, clojure, cmake, cobol, coffeescript, cpp, cpp-qt, csharp, css, cuesheet, d, dcl, dcpu16, dcs, delphi, diff, div, dos, dot, e, ecmascript, eiffel, email, epc, erlang, euphoria, f1, falcon, fo, fortran, freebasic, freeswitch, fsharp, gambas, gdb, genero, genie, gettext, glsl, gml, gnuplot, go, groovy, gwbasic, haskell, haxe, hicest, hq9plus, html4strict, html5, icon, idl, ini, inno, intercal, io, j, java, java5, javascript, jquery, kixtart, klonec, klonecpp, latex, lb, ldif, lisp, llvm, locobasic, logtalk, lolcode, lotusformulas, lotusscript, lscript, lsl2, lua, m68k, magiksf, make, mapbasic, matlab, mirc, mmix, modula2, modula3, mpasm, mxml, mysql, nagios, netrexx, newlisp, nsis, oberon2, objc, objeck, ocaml, ocaml-brief, octave, oobas, oorexx, oracle11, oracle8, oxygene, oz, parasail, parigp, pascal, pcre, per, perl, perl6, pf, php, php-brief, pic16, pike, pixelbender, pli, plsql, postgresql, povray, powerbuilder, powershell, proftpd, progress, prolog, properties, providex, purebasic, pycon, pys60, python, q, qbasic, rails, rebol, reg, rexx, robots, rpmspec, rsplus, ruby, sas, scala, scheme, scilab, sdlbasic, smalltalk, smarty, spark, sparql, sql, stonescript, systemverilog, tcl, teraterm, text, thinbasic, tsql, typoscript, unicon, upc, urbi, uscript, vala, vb, vbnet, vedit, verilog, vhdl, vim, visualfoxpro, visualprolog, whitespace, whois, winbatch, xbasic, xml, xorg_conf, xpp, yaml, z80, zxbasic
#include "gfx.h"
#include "stm32f4xx_hal.h"
systemticks_t gfxSystemTicks(void)
{
return HAL_GetTick();
}
systemticks_t gfxMillisecondsToTicks(delaytime_t ms)
{
return ms;
}
