mirror of https://github.com/zeldaret/mm.git
50 lines
1.5 KiB
ArmAsm
50 lines
1.5 KiB
ArmAsm
#include "PR/asm.h"
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#include "PR/regdef.h"
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#include "boot.h"
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.text
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#define PAD_TO 0x60
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#define LA(reg, sym) la reg, sym
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#if !defined(AVOID_UB)
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/* Old assembler workarounds: The makerom tool in the N64 SDK was given the bss segment size as a const
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* literal, and since this literal was < 0x10000 it was loaded in one instruction. We don't have access
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* to the bss segment size until we link everything so we cannot do the same thing. Instead we must load
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* only the lower 16 bits of the bss size for matching.
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* When AVOID_UB is enabled, don't do this and instead load the full symbol value, otherwise not all of
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* bss may be cleared. */
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# if defined(__sgi)
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# define LOAD_BSS_SIZE(reg) li reg, %half(_bootSegmentBssSize)
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# else
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# define LOAD_BSS_SIZE(reg) ori reg, zero, %lo(_bootSegmentBssSize)
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# endif
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#else
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# define LOAD_BSS_SIZE(reg) LA(reg, _bootSegmentBssSize)
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#endif
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LEAF(entrypoint)
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/* Clear boot segment .bss */
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LA( t0, _bootSegmentBssStart)
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LOAD_BSS_SIZE(t1)
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.clear_bss:
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sw zero, 0(t0)
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sw zero, 4(t0)
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addi t0, t0, 8
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addi t1, t1, -8
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bnez t1, .clear_bss
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/* Set up stack and enter program code */
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LA( sp, sBootStack + BOOT_STACK_SIZE)
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LA( t2, bootproc)
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jr t2
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END(entrypoint)
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#ifdef __sgi
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/* IDO can't take absolute differences of symbols so the size of the above is hardcoded */
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.space PAD_TO - 0x34
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#else
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/* Pad to a total size taking into account the size of the above */
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.space PAD_TO - (. - entrypoint)
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#endif
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