| 1 | /* |
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| 2 | * writechr: Write a single character in AL to the console without |
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| 3 | * mangling any registers. This does raw console writes, |
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| 4 | * since some PXE BIOSes seem to interfere regular console I/O. |
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| 5 | */ |
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| 6 | #include <sys/io.h> |
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| 7 | #include <fs.h> |
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| 8 | #include <com32.h> |
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| 9 | |
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| 10 | #include "bios.h" |
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| 11 | #include "graphics.h" |
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| 12 | #include <syslinux/video.h> |
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| 13 | |
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| 14 | __export void writechr(char data) |
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| 15 | { |
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| 16 | if (UsingVGA & 0x08) |
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| 17 | syslinux_force_text_mode(); |
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| 18 | |
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| 19 | write_serial(data); /* write to serial port if needed */ |
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| 20 | |
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| 21 | /* Write to screen? */ |
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| 22 | if (DisplayCon & 0x01) { |
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| 23 | com32sys_t ireg, oreg; |
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| 24 | bool curxyok = false; |
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| 25 | uint16_t dx; |
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| 26 | |
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| 27 | memset(&ireg, 0, sizeof ireg); |
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| 28 | ireg.ebx.b[1] = *(uint8_t *)BIOS_page; |
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| 29 | ireg.eax.b[1] = 0x03; /* Read cursor position */ |
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| 30 | __intcall(0x10, &ireg, &oreg); |
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| 31 | ireg.edx.l = oreg.edx.l; |
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| 32 | |
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| 33 | switch (data) { |
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| 34 | case 8: |
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| 35 | if (ireg.edx.b[0]--) { |
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| 36 | curxyok = true; |
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| 37 | break; |
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| 38 | } |
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| 39 | |
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| 40 | ireg.edx.b[0] = VidCols; |
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| 41 | if (ireg.edx.b[1]--) { |
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| 42 | curxyok = true; |
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| 43 | break; |
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| 44 | } |
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| 45 | |
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| 46 | ireg.edx.b[1] = 0; |
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| 47 | curxyok = true; |
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| 48 | break; |
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| 49 | case 13: |
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| 50 | ireg.edx.b[0] = 0; |
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| 51 | curxyok = true; |
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| 52 | break; |
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| 53 | case 10: |
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| 54 | break; |
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| 55 | default: |
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| 56 | dx = ireg.edx.w[0]; |
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| 57 | |
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| 58 | ireg.ebx.b[1] = *(uint8_t *)BIOS_page; |
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| 59 | ireg.ebx.b[0] = 0x07; /* White on black */ |
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| 60 | ireg.ecx.w[0] = 1; /* One only */ |
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| 61 | ireg.eax.b[0] = data; |
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| 62 | ireg.eax.b[1] = 0x09; /* Write char and attribute */ |
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| 63 | __intcall(0x10, &ireg, NULL); |
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| 64 | |
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| 65 | ireg.edx.w[0] = dx; |
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| 66 | if (++ireg.edx.b[0] <= VidCols) |
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| 67 | curxyok = true; |
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| 68 | else |
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| 69 | ireg.edx.b[0] = 0; |
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| 70 | } |
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| 71 | |
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| 72 | if (!curxyok && ++ireg.edx.b[1] > VidRows) { |
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| 73 | /* Scroll */ |
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| 74 | ireg.edx.b[1]--; |
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| 75 | ireg.ebx.b[1] = *(uint8_t *)BIOS_page; |
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| 76 | ireg.eax.b[1] = 0x02; |
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| 77 | __intcall(0x10, &ireg, NULL); |
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| 78 | |
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| 79 | ireg.eax.w[0] = 0x0601; /* Scroll up one line */ |
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| 80 | ireg.ebx.b[1] = ScrollAttribute; |
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| 81 | ireg.ecx.w[0] = 0; |
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| 82 | ireg.edx.w[0] = ScreenSize; /* The whole screen */ |
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| 83 | __intcall(0x10, &ireg, NULL); |
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| 84 | } else { |
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| 85 | ireg.ebx.b[1] = *(uint8_t *)BIOS_page; |
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| 86 | ireg.eax.b[1] = 0x02; /* Set cursor position */ |
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| 87 | __intcall(0x10, &ireg, NULL); |
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| 88 | } |
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| 89 | } |
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| 90 | } |
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| 91 | |
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| 92 | void pm_writechr(com32sys_t *regs) |
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| 93 | { |
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| 94 | writechr(regs->eax.b[0]); |
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| 95 | } |
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