23ebd514c1
Timers aren't firing yet so the system locks up as soon as any timeout is involved. Enough to run the command line for a bit.
76 lines
1.8 KiB
ArmAsm
76 lines
1.8 KiB
ArmAsm
/*
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* Copyright (c) 2019 Travis Geiselbrecht
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*
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* Use of this source code is governed by a MIT-style
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* license that can be found in the LICENSE file or at
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* https://opensource.org/licenses/MIT
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*/
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.section .text.boot
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.globl _start
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_start:
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nop
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nop
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// save our bootargs
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moval bootargs_end,%sp
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pushr $0x1fff
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// see if we need to be relocated
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movab _start, %r0 // where we are
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movl $_start, %r1 // where we want to be
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cmpl %r0,%r1
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beql relocated
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// compute the copy length
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subl3 %r1, $__data_end, %r2
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// copy us down to the final location
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1:
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movb (%r0)+,(%r1)+
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sobgtr %r2,1b
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// zero bss
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subl3 $_end, $__data_end, %r2
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1:
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movb $0,(%r1)+
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sobgtr %r2,1b
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// branch to our new spot
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// use a REI to make sure the cpu dumps the pipeline
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moval boot_stack_end,%sp // set the stack temporarily in the current memory spot
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movpsl -(%sp)
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movl $relocated, -(%sp)
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rei
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relocated:
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// switch to kernel stack
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moval boot_stack_end,%sp // set the interrupt stack in the relocated spot
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movpsl -(%sp) // push the psl on the stack
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bicl2 $(1<<26),(%sp) // clear bit 26 (IS)
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moval 1f,-(%sp) // push the address of the end of this routine
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rei // rei to it, loading the new PSL
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1:
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// now we should be using the kernel stack pointer, so re-set it
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moval boot_stack_end,%sp
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// branch into main and we're done
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calls $0, lk_main
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halt
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.section .data
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// declare bootargs here to make sure it goes in the data segment, since it's
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// saved before the bss is zeroed out.
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.balign 4
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.globl bootargs
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bootargs:
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.skip 13*4
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bootargs_end:
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.section .bss
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.balign 4
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boot_stack:
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.skip 1024
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boot_stack_end:
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