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| 2 | pj | 1 | |
| 2 | /* Project: OSLib |
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| 3 | * Description: The OS Construction Kit |
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| 4 | * Date: 1.6.2000 |
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| 5 | * Idea by: Luca Abeni & Gerardo Lamastra |
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| 6 | * |
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| 7 | * OSLib is an SO project aimed at developing a common, easy-to-use |
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| 8 | * low-level infrastructure for developing OS kernels and Embedded |
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| 9 | * Applications; it partially derives from the HARTIK project but it |
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| 10 | * currently is independently developed. |
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| 11 | * |
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| 12 | * OSLib is distributed under GPL License, and some of its code has |
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| 13 | * been derived from the Linux kernel source; also some important |
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| 14 | * ideas come from studying the DJGPP go32 extender. |
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| 15 | * |
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| 16 | * We acknowledge the Linux Community, Free Software Foundation, |
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| 17 | * D.J. Delorie and all the other developers who believe in the |
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| 18 | * freedom of software and ideas. |
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| 19 | * |
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| 20 | * For legalese, check out the included GPL license. |
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| 21 | */ |
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| 22 | |||
| 23 | /* |
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| 24 | FPU Context switch & management functions! |
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| 25 | Generic 32 bit module |
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| 26 | */ |
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| 27 | |||
| 28 | #include <ll/i386/hw-data.h> |
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| 29 | #include <ll/i386/hw-instr.h> |
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| 30 | #include <ll/i386/mem.h> |
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| 31 | |||
| 32 | #include <ll/i386/tss-ctx.h> |
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| 33 | |||
| 34 | FILE(FPU); |
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| 35 | |||
| 36 | extern TSS TSS_table[]; |
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| 37 | |||
| 38 | BYTE LL_FPU_savearea[FPU_CONTEXT_SIZE]; /* Global FPU scratch SaveArea */ |
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| 39 | #ifdef __FPU_DEBUG__ |
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| 40 | long int ndp_called = 0, ndp_switched = 0; |
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| 41 | #endif |
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| 42 | |||
| 43 | /* FPU context management */ |
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| 44 | static CONTEXT LL_has_FPU = TSSMain; |
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| 45 | |||
| 46 | /* As the 8086 does not have an hardware mechanism to support task */ |
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| 47 | /* switch, also the FPU context switch is implemented via software. */ |
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| 48 | /* When a preemption occurs, if the task is marked as a MATH task, the */ |
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| 49 | /* preemption routine will save/restore the FPU context. */ |
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| 50 | /* The hook is called whenever a FPU context switch is necessarty */ |
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| 51 | |||
| 52 | void ll_FPU_hook(void) |
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| 53 | { |
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| 54 | clts(); |
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| 55 | #ifdef __FPU_DEBUG__ |
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| 56 | ndp_called++; |
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| 57 | #endif |
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| 58 | if (LL_has_FPU == TSSsel2index(get_TR())) |
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| 59 | return; |
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| 60 | #ifdef __FPU_DEBUG__ |
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| 61 | ndp_switched++; |
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| 62 | #endif |
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| 63 | |||
| 64 | #if 0 |
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| 65 | LL_FPU_save(); |
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| 66 | memcpy(TSS_table[LL_has_FPU].ctx_FPU, LL_FPU_savearea, |
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| 67 | FPU_CONTEXT_SIZE); |
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| 68 | #else |
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| 69 | save_fpu(&(TSS_table[LL_has_FPU])); |
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| 70 | #endif |
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| 71 | |||
| 72 | LL_has_FPU = TSSsel2index(get_TR()); |
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| 73 | |||
| 74 | #if 1 |
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| 75 | memcpy(LL_FPU_savearea, TSS_table[LL_has_FPU].ctx_FPU, |
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| 76 | FPU_CONTEXT_SIZE); |
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| 77 | LL_FPU_restore(); |
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| 78 | #else |
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| 79 | restore_fpu(&(TSS_table[LL_has_FPU])); |
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| 80 | #endif |
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| 81 | return; |
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| 82 | } |
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| 83 | |||
| 84 | CONTEXT LL_FPU_get_task(void) |
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| 85 | { |
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| 86 | return (LL_has_FPU); |
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| 87 | } |