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cga use span to address screen memory

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This commit is contained in:
Christoph Urlacher
2022-07-24 22:43:07 +02:00
parent 7e046b6f89
commit f711e41216
2 changed files with 13 additions and 8 deletions
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14
c_os/devices/CGA.cc
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@ -17,6 +17,10 @@
const IOport CGA::index_port(0x3d4);
const IOport CGA::data_port(0x3d5);
bse::span<CGA::cga_char_t, CGA::ROWS * CGA::COLUMNS> CGA::SCREEN{reinterpret_cast<CGA::cga_char_t*>(0xb8000U)};
bse::span<CGA::cga_line_t, CGA::ROWS> CGA::SCREEN_ROWS{reinterpret_cast<CGA::cga_line_t*>(0xb8000U)};
CGA::cga_page_t* CGA::SCREEN_PAGE {reinterpret_cast<CGA::cga_page_t*>(0xb8000U)};
/*****************************************************************************
* Methode: CGA::setpos *
*---------------------------------------------------------------------------*
@ -82,7 +86,7 @@ void CGA::show(unsigned int x, unsigned int y, char character, unsigned char att
return;
}
cga_char_t* pos = reinterpret_cast<cga_char_t*>(CGA_START) + x + y * COLUMNS;
cga_char_t* pos= SCREEN[x + y * COLUMNS];
pos->cga_char = character;
pos->cga_attribute = attrib;
}
@ -165,12 +169,10 @@ void CGA::scrollup() const {
/* Hier muss Code eingefuegt werden */
// Move up
bse::memcpy<cga_line_t>(reinterpret_cast<cga_line_t*>(CGA_START),
reinterpret_cast<cga_line_t*>(CGA_START) + 1,
ROWS - 1);
bse::memcpy<cga_line_t>(SCREEN_ROWS[0], SCREEN_ROWS[1], ROWS - 1);
// Clear last line
bse::zero<cga_line_t>(reinterpret_cast<cga_line_t*>(CGA_START) + ROWS - 1);
bse::zero<cga_line_t>(SCREEN_ROWS[ROWS - 1]);
}
/*****************************************************************************
@ -182,7 +184,7 @@ void CGA::clear() {
/* Hier muess Code eingefuegt werden */
bse::zero<cga_page_t>(reinterpret_cast<cga_page_t*>(CGA_START));
bse::zero<cga_page_t>(SCREEN_PAGE);
setpos(0, 0);
}

7
c_os/devices/CGA.h
View File

@ -16,6 +16,7 @@
#include "kernel/IOport.h"
#include "user/lib/Array.h"
#include "user/lib/Span.h"
#include "user/lib/String.h"
class CGA {
@ -34,8 +35,6 @@ public:
// virtual ~CGA() = default;
static const unsigned int CGA_START = 0xb8000U;
// Konstanten fuer die moeglichen Farben im Attribut-Byte.
typedef enum {
BLACK,
@ -78,6 +77,10 @@ public:
bse::array<cga_line_t, ROWS> cga_page;
};
static bse::span<cga_char_t, ROWS * COLUMNS> SCREEN;
static bse::span<cga_line_t, ROWS> SCREEN_ROWS;
static cga_page_t* SCREEN_PAGE; // No span because can't address anything in [0, 1]
// Setzen des Cursors in Spalte x und Zeile y.
static void setpos(unsigned int x, unsigned int y);