1 | #ifdef CONFIG_FB
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2 |
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3 | #define MULTIBOOT_LOADER_MAGIC 0x2BADB002
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4 | #define MBINFO_BIT_CMDLINE 2
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5 | #define MBINFO_OFFSET_CMDLINE 16
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6 |
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7 | # copy real mode VESA initialization code
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8 |
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9 | mov $vesa_init, %esi
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10 | mov $VESA_INIT_SEGMENT << 4, %edi
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11 | mov $e_vesa_init - vesa_init, %ecx
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12 | rep movsb
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13 |
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14 | # check for GRUB command line
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15 |
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16 | mov grub_eax, %eax
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17 | cmp $MULTIBOOT_LOADER_MAGIC, %eax
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18 | jne no_cmdline
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19 |
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20 | mov grub_ebx, %ebx
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21 | mov (%ebx), %eax
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22 | bt $MBINFO_BIT_CMDLINE, %eax
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23 | jnc no_cmdline
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24 |
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25 | # skip the kernel path in command line
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26 |
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27 | mov MBINFO_OFFSET_CMDLINE(%ebx), %esi
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28 |
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29 | skip_loop:
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30 | lodsb
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31 |
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32 | cmp $0, %al
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33 | je no_cmdline
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34 |
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35 | cmp $' ', %al
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36 | je skip_loop_done
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37 |
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38 | jmp skip_loop
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39 | skip_loop_done:
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40 |
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41 | space_loop:
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42 | mov (%esi), %al
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43 |
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44 | cmp $0, %al
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45 | je no_cmdline
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46 |
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47 | cmp $' ', %al
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48 | jne space_loop_done
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49 |
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50 | inc %esi
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51 | jmp space_loop
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52 | space_loop_done:
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53 |
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54 | # copy at most 23 characters from command line
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55 |
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56 | mov $VESA_INIT_SEGMENT << 4, %edi
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57 | add $default_mode - vesa_init, %edi
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58 | mov $23, %ecx
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59 |
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60 | cmd_loop:
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61 | lodsb
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62 | stosb
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63 |
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64 | cmp $0, %al
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65 | je cmd_loop_done
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66 |
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67 | loop cmd_loop
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68 | cmd_loop_done:
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69 |
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70 | # zero termination
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71 |
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72 | xor %eax, %eax
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73 | stosb
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74 |
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75 | no_cmdline:
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76 |
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77 | # jump to the real mode
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78 |
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79 | mov $VESA_INIT_SEGMENT << 4, %edi
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80 | jmpl *%edi
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81 |
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82 | vesa_meeting_point:
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83 | # returned back to protected mode
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84 |
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85 | mov %ax, KA2PA(vesa_scanline)
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86 | shr $16, %eax
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87 | mov %ax, KA2PA(vesa_bpp)
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88 |
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89 | mov %bx, KA2PA(vesa_height)
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90 | shr $16, %ebx
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91 | mov %bx, KA2PA(vesa_width)
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92 |
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93 | mov %dl, KA2PA(vesa_green_pos)
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94 | shr $8, %edx
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95 | mov %dl, KA2PA(vesa_green_mask)
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96 | shr $8, %edx
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97 | mov %dl, KA2PA(vesa_red_pos)
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98 | shr $8, %edx
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99 | mov %dl, KA2PA(vesa_red_mask)
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100 |
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101 | mov %esi, %edx
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102 | mov %dl, KA2PA(vesa_blue_pos)
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103 | shr $8, %edx
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104 | mov %dl, KA2PA(vesa_blue_mask)
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105 |
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106 | mov %edi, KA2PA(vesa_ph_addr)
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107 | #endif
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