4983adfa2c
the new raspberry pi 4 firmware for arm64 seems to have broken atag support. so we now parse the device tree structure to get the bootargs and memory configuration.
57 lines
807 B
ArmAsm
57 lines
807 B
ArmAsm
#include "mem.h"
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#include "sysreg.h"
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#undef SYSREG
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#define SYSREG(op0,op1,Cn,Cm,op2) SPR(((op0)<<19|(op1)<<16|(Cn)<<12|(Cm)<<8|(op2)<<5))
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TEXT _start(SB), 1, $-4
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MOV $setSB(SB), R28
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MRS MPIDR_EL1, R27
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ANDW $(MAXMACH-1), R27
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LSL $3, R27
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ADD $(SPINTABLE-KZERO), R27
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CBZ R0, _mmuoff
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MOV R0, (R27)
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MOV code+8(FP), R1
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MOVWU size+16(FP), R2
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BIC $3, R2
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ADD R1, R2, R3
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_copy:
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MOVW (R1)4!, R4
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MOVW R4, (R0)4!
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CMP R1, R3
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BNE _copy
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BL cachedwbinv(SB)
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BL l2cacheuwbinv(SB)
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SEVL
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_mmuoff:
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ISB $SY
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MRS SCTLR_EL1, R0
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BIC $(1<<0 | 1<<2 | 1<<12), R0
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ISB $SY
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MSR R0, SCTLR_EL1
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ISB $SY
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DSB $NSHST
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TLBI R0, 0,8,7,0 /* VMALLE1 */
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DSB $NSH
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ISB $SY
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BL cachedwbinv(SB)
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BL cacheiinv(SB)
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MOVWU $0, R0
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MOVWU $0, R1
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MOVWU $0, R2
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MOVWU $0, R3
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_wait:
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WFE
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MOV (R27), LR
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CBZ LR, _wait
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RETURN
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