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Rev | Author | Line No. | Line |
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4127 | decky | 1 | #ifdef CONFIG_FB |
4128 | decky | 2 | |
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 | |||
7 | # copy real mode VESA initialization code |
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8 | |||
4127 | decky | 9 | mov $vesa_init, %esi |
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 | |||
4128 | decky | 14 | # check for GRUB command line |
15 | |||
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 | |||
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 | |||
25 | # skip the kernel path in command line |
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26 | |||
27 | mov MBINFO_OFFSET_CMDLINE(%ebx), %esi |
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28 | |||
29 | skip_loop: |
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30 | lodsb |
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31 | |||
32 | cmp $0, %al |
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33 | je no_cmdline |
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34 | |||
35 | cmp $' ', %al |
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36 | je skip_loop_done |
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37 | |||
38 | jmp skip_loop |
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39 | skip_loop_done: |
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40 | |||
41 | mov (%esi), %al |
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42 | cmp $0, %al |
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43 | je no_cmdline |
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44 | |||
45 | # copy at most 23 characters from command line |
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46 | |||
4127 | decky | 47 | mov $VESA_INIT_SEGMENT << 4, %edi |
4128 | decky | 48 | add $default_mode - vesa_init, %edi |
49 | mov $23, %ecx |
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50 | |||
51 | cmd_loop: |
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52 | lodsb |
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53 | stosb |
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54 | |||
55 | cmp $0, %al |
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56 | je cmd_loop_done |
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57 | |||
58 | loop cmd_loop |
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59 | cmd_loop_done: |
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60 | |||
61 | # zero termination |
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62 | |||
63 | xor %eax, %eax |
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64 | stosb |
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65 | |||
66 | no_cmdline: |
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67 | |||
68 | # jump to the real mode |
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69 | |||
70 | mov $VESA_INIT_SEGMENT << 4, %edi |
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4127 | decky | 71 | jmpl *%edi |
72 | |||
73 | vesa_meeting_point: |
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4128 | decky | 74 | # returned back to protected mode |
75 | |||
4127 | decky | 76 | mov %esi, KA2PA(vesa_ph_addr) |
77 | mov %di, KA2PA(vesa_height) |
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78 | shr $16, %edi |
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79 | mov %di, KA2PA(vesa_width) |
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80 | mov %bx, KA2PA(vesa_scanline) |
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81 | shr $16, %ebx |
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82 | mov %bx, KA2PA(vesa_bpp) |
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83 | #endif |