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bztsrc--bootboot/mykernel/kernel.c
2020-08-28 19:18:34 +02:00

107 lines
3.8 KiB
C

/*
* mykernel/kernel.c
*
* Copyright (C) 2017 - 2020 bzt (bztsrc@gitlab)
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* This file is part of the BOOTBOOT Protocol package.
* @brief A sample BOOTBOOT compatible kernel
*
*/
/* function to display a string, see below */
void puts(char *s);
/* we don't assume stdint.h exists */
typedef short int int16_t;
typedef unsigned char uint8_t;
typedef unsigned short int uint16_t;
typedef unsigned int uint32_t;
typedef unsigned long int uint64_t;
#include <bootboot.h>
/* imported virtual addresses, see linker script */
extern BOOTBOOT bootboot; // see bootboot.h
extern unsigned char environment[4096]; // configuration, UTF-8 text key=value pairs
extern uint8_t fb; // linear framebuffer mapped
/******************************************
* Entry point, called by BOOTBOOT Loader *
******************************************/
void _start()
{
/*** NOTE: this code runs on all cores in parallel ***/
int x, y, s=bootboot.fb_scanline, w=bootboot.fb_width, h=bootboot.fb_height;
// cross-hair to see screen dimension detected correctly
for(y=0;y<h;y++) { *((uint32_t*)(&fb + s*y + (w*2)))=0x00FFFFFF; }
for(x=0;x<w;x++) { *((uint32_t*)(&fb + s*(h/2)+x*4))=0x00FFFFFF; }
// red, green, blue boxes in order
for(y=0;y<20;y++) { for(x=0;x<20;x++) { *((uint32_t*)(&fb + s*(y+20) + (x+20)*4))=0x00FF0000; } }
for(y=0;y<20;y++) { for(x=0;x<20;x++) { *((uint32_t*)(&fb + s*(y+20) + (x+50)*4))=0x0000FF00; } }
for(y=0;y<20;y++) { for(x=0;x<20;x++) { *((uint32_t*)(&fb + s*(y+20) + (x+80)*4))=0x000000FF; } }
// say hello
puts("Hello from a simple BOOTBOOT kernel");
// hang for now
while(1);
}
/**************************
* Display text on screen *
**************************/
typedef struct {
uint32_t magic;
uint32_t version;
uint32_t headersize;
uint32_t flags;
uint32_t numglyph;
uint32_t bytesperglyph;
uint32_t height;
uint32_t width;
uint8_t glyphs;
} __attribute__((packed)) psf2_t;
extern volatile unsigned char _binary_font_psf_start;
void puts(char *s)
{
psf2_t *font = (psf2_t*)&_binary_font_psf_start;
int x,y,kx=0,line,mask,offs;
int bpl=(font->width+7)/8;
while(*s) {
unsigned char *glyph = (unsigned char*)&_binary_font_psf_start + font->headersize +
(*s>0&&*s<font->numglyph?*s:0)*font->bytesperglyph;
offs = (kx * (font->width+1) * 4);
for(y=0;y<font->height;y++) {
line=offs; mask=1<<(font->width-1);
for(x=0;x<font->width;x++) {
*((uint32_t*)((uint64_t)&fb+line))=((int)*glyph) & (mask)?0xFFFFFF:0;
mask>>=1; line+=4;
}
*((uint32_t*)((uint64_t)&fb+line))=0; glyph+=bpl; offs+=bootboot.fb_scanline;
}
s++; kx++;
}
}