147 lines
4.9 KiB
ArmAsm
147 lines
4.9 KiB
ArmAsm
/*******************************************************
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* ------------------------------------------------- *
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* | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | *
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* ------------------------------------------------- *
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* | 0 | 8 | 16 | 24 | *
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* ------------------------------------------------- *
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* | t.fctx | t.data | r2 | r6 | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | *
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* ------------------------------------------------- *
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* | 32 | 40 | 48 | 56 | *
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* ------------------------------------------------- *
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* | r7 | r8 | r9 | r10 | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | *
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* ------------------------------------------------- *
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* | 64 | 72 | 80 | 88 | *
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* ------------------------------------------------- *
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* | r11 | r12 | r13 | r14 | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | *
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* ------------------------------------------------- *
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* | 96 | 104 | 112 | 120 | *
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* ------------------------------------------------- *
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* | f8 | f9 | f10 | f11 | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | *
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* ------------------------------------------------- *
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* | 128 | 136 | 144 | 152 | *
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* ------------------------------------------------- *
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* | f12 | f13 | f14 | f15 | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | *
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* ------------------------------------------------- *
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* | 160 | 168 | 176 | | *
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* ------------------------------------------------- *
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* | fpc | pc | | | *
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* ------------------------------------------------- *
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*******************************************************/
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.text
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.align 8
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.global ontop_fcontext
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.type ontop_fcontext, @function
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#define ARG_OFFSET 0
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#define GR_OFFSET 16
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#define R14_OFFSET 88
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#define FP_OFFSET 96
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#define FPC_OFFSET 160
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#define PC_OFFSET 168
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#define CONTEXT_SIZE 176
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/*
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typedef void* fcontext_t;
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struct transfer_t {
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fcontext_t fctx;
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void * data;
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};
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transfer_t ontop_fcontext( fcontext_t const to,
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void * vp,
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transfer_t (* fn)( transfer_t) );
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Incoming args
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r2 - Hidden argument to the location where the return transfer_t needs to be returned
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r3 - Target context
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r4 - Data pointer
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r5 - Function to be executed
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This implementation assumes that ontop_fcontext will never be called with target contexts
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created via make_fcontext.
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*/
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ontop_fcontext:
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/* Reserve stack space to store the current context. */
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aghi %r15,-CONTEXT_SIZE
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/* Save the argument register holding the location of the return value. */
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stg %r2,GR_OFFSET(%r15)
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/* Save the call-saved general purpose registers. */
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stmg %r6,%r14,GR_OFFSET+8(%r15)
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/* Save call-saved floating point registers. */
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std %f8,FP_OFFSET(%r15)
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std %f9,FP_OFFSET+8(%r15)
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std %f10,FP_OFFSET+16(%r15)
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std %f11,FP_OFFSET+24(%r15)
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std %f12,FP_OFFSET+32(%r15)
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std %f13,FP_OFFSET+40(%r15)
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std %f14,FP_OFFSET+48(%r15)
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std %f15,FP_OFFSET+56(%r15)
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/* Save the return address as current pc. */
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stg %r14,PC_OFFSET(%r15)
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/* Save the floating point control register. */
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stfpc FPC_OFFSET(%r15)
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/* Backup the stack pointer pointing to the old context-data into r1. */
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lgr %r1,%r15
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/* Load the new context pointer as stack pointer. */
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lgr %r15,%r3
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/* Restore the call-saved GPRs from the new context. */
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lmg %r6,%r14,GR_OFFSET+8(%r15)
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/* Restore call-saved floating point registers. */
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ld %f8,FP_OFFSET(%r15)
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ld %f9,FP_OFFSET+8(%r15)
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ld %f10,FP_OFFSET+16(%r15)
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ld %f11,FP_OFFSET+24(%r15)
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ld %f12,FP_OFFSET+32(%r15)
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ld %f13,FP_OFFSET+40(%r15)
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ld %f14,FP_OFFSET+48(%r15)
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ld %f15,FP_OFFSET+56(%r15)
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/* Load the floating point control register. */
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lfpc FPC_OFFSET(%r15)
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/* Store the transfer_t values located in the saved context. */
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stg %r1,0(%r1) /* transfer_t.fctx = old context */
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stg %r4,8(%r1) /* transfer_t.data = data */
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/* Set up the arguments for the target function. */
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lg %r2,GR_OFFSET(%r15)
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lgr %r3,%r1
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/* Deallocate the context. */
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aghi %r15,CONTEXT_SIZE
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br %r5
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.size ontop_fcontext,.-ontop_fcontext
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.section .note.GNU-stack,"",%progbits
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