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https://opencores.org/ocsvn/neorv32/neorv32/trunk
[/] [neorv32/] [trunk/] [sw/] [common/] [crt0.S] - Diff between revs 73 and 74
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Rev 74 |
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Line 45... |
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// ************************************************************************************************
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// ************************************************************************************************
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// This is the very first instruction that is executed after hardware reset. It ensures that x0 is
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// This is the very first instruction that is executed after hardware reset. It ensures that x0 is
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// written at least once - the CPU HW will ensure it is always set to zero on any write access.
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// written at least once - the CPU HW will ensure it is always set to zero on any write access.
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//
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// Furthermore, we have to disable ALL interrupts, which is required if this code is part of a
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// program uploaded by the on-chip debugger (potentionally taking control from the bootloader).
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// We setup a new stack pointer here and WE DO NOT WANT TO trap to an outdated trap handler with
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// a modified stack pointer.
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// ************************************************************************************************
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// ************************************************************************************************
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lui zero, 0 // "dummy" instruction that uses no reg-file input operands at all
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csrrci zero, mstatus, (1<<3) // disable global interrupt flag and write "anything" to x0
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// ************************************************************************************************
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// ************************************************************************************************
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// Setup pointers using linker script symbols
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// Setup pointers using linker script symbols
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// ************************************************************************************************
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// ************************************************************************************************
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