2024-08-07 11:26:07 +02:00
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# For a quick reference on RISC-V assembly:
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# https://risc-v.guru/instructions/
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# Kernel entry point
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#
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# qemu -kernel loads the kernel at 0x80000000
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# and causes each hart (i.e. CPU) to jump there.
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# kernel.ld causes the following code to
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# be placed at 0x80000000.
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2019-05-31 15:45:59 +02:00
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.section .text
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2020-10-20 15:42:34 +02:00
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.global _entry
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2019-05-31 15:45:59 +02:00
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_entry:
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2022-08-09 20:17:46 +02:00
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# set up a stack for C.
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2019-07-23 17:14:10 +02:00
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# stack0 is declared in start.c,
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# with a 4096-byte stack per CPU.
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# sp = stack0 + (hartid * 4096)
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2019-05-31 15:45:59 +02:00
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la sp, stack0
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2019-06-05 17:42:03 +02:00
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li a0, 1024*4
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2022-08-09 20:17:46 +02:00
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csrr a1, mhartid
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2019-06-05 17:42:03 +02:00
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addi a1, a1, 1
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mul a0, a0, a1
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add sp, sp, a0
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2022-08-09 20:17:46 +02:00
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# jump to start() in start.c
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2019-07-23 20:31:12 +02:00
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call start
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2020-08-15 11:46:32 +02:00
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spin:
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j spin
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