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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 2 | pj | 1 | /* Project: OSLib |
| 2 | * Description: The OS Construction Kit |
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| 3 | * Date: 1.6.2000 |
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| 4 | * Idea by: Luca Abeni & Gerardo Lamastra |
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| 5 | * |
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| 6 | * OSLib is an SO project aimed at developing a common, easy-to-use |
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| 7 | * low-level infrastructure for developing OS kernels and Embedded |
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| 8 | * Applications; it partially derives from the HARTIK project but it |
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| 9 | * currently is independently developed. |
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| 10 | * |
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| 11 | * OSLib is distributed under GPL License, and some of its code has |
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| 12 | * been derived from the Linux kernel source; also some important |
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| 13 | * ideas come from studying the DJGPP go32 extender. |
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| 14 | * |
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| 15 | * We acknowledge the Linux Community, Free Software Foundation, |
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| 16 | * D.J. Delorie and all the other developers who believe in the |
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| 17 | * freedom of software and ideas. |
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| 18 | * |
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| 19 | * For legalese, check out the included GPL license. |
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| 20 | */ |
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| 21 | |||
| 22 | /* The OSLib (flat space) <-> Phisical address conversion */ |
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| 23 | |||
| 24 | #include <ll/i386/hw-func.h> |
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| 25 | #include <ll/i386/mem.h> |
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| 26 | |||
| 27 | FILE(X - Conv); |
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| 28 | |||
| 29 | /* Conversion between PM address space & phisical address space */ |
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| 30 | /* If we do not support paging we need to relocate the .ELF executable */ |
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| 31 | /* using the segment register; however we also need to access all the */ |
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| 32 | /* phisical memory; for example if we allocate some memory (phisical) */ |
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| 33 | /* and we use a pointer to access that memory, the pointer will use */ |
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| 34 | /* the current DS to address the specified offset; but the phisical */ |
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| 35 | /* offset cannot be used because the base of DS is not zero as required */ |
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| 36 | /* to access phisical memory; the DS base is stored by X into the */ |
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| 37 | /* exec_base field of _X_info! This is the key to traslate ELF address */ |
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| 38 | /* into phisical address & viceversa */ |
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| 39 | |||
| 40 | /* |
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| 41 | DWORD appl2linear(void *p) |
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| 42 | { |
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| 43 | unsigned long result; |
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| 44 | result = (DWORD)(p) + _X_info->exec_base; |
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| 45 | return(result); |
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| 46 | } |
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| 47 | |||
| 48 | void *linear2appl(DWORD a) |
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| 49 | { |
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| 50 | void *p; |
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| 51 | if (a < _X_info->exec_base) p = NULL; |
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| 52 | else p = (void *)(a-_X_info->exec_base); |
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| 53 | return(p); |
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| 54 | } |
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| 55 | */ |
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| 56 | |||
| 57 | LIN_ADDR addr2linear(unsigned short seg, unsigned long offset) |
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| 58 | { |
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| 59 | LIN_ADDR flatbase; |
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| 60 | flatbase = (LIN_ADDR) GDT_read(seg, NULL, NULL, NULL); |
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| 61 | return (flatbase + offset); |
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| 62 | } |