e3a463e585
The current code results in `error: invalid reassignment of non-absolute variable 'isr_stub_start'`. Use a numbered label instead (as that can be reassigned) and reference the last occurrence using the b suffix.
129 lines
3.1 KiB
ArmAsm
129 lines
3.1 KiB
ArmAsm
/*
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* Copyright (c) 2009 Corey Tabaka
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* Copyright (c) 2015 Intel Corporation
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* Copyright (c) 2016 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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#include <lk/asm.h>
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#include <arch/x86/descriptor.h>
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#define NUM_INT 0x31
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#define NUM_EXC 0x14
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.text
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/* interrupt service routine stubs */
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_isr:
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.set i, 0
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.rept NUM_INT
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100: /* unnamed label for start of isr stub */
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.if i == 8 || (i >= 10 && i <= 14) || i == 17
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nop /* error code pushed by exception */
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nop /* 2 nops are the same length as push byte */
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pushl $i /* interrupt number */
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jmp interrupt_common
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.else
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pushl $0 /* fill in error code in iframe */
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pushl $i /* interrupt number */
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jmp interrupt_common
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.endif
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.set i, i + 1
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.endr
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/* figure out the length of a single isr stub (usually 6 or 9 bytes) */
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.set isr_stub_len, . - 100b
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/* annoying, but force AS to use the same (longer) encoding of jmp for all of the stubs */
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.fill 256
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FUNCTION(interrupt_common)
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cld
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pushl %gs /* save segment registers */
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pushl %fs
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pushl %es
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pushl %ds
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pusha /* save general purpose registers */
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movl $DATA_SELECTOR, %eax /* put known good value in segment registers */
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movl %eax, %gs
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movl %eax, %fs
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movl %eax, %es
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movl %eax, %ds
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movl %esp, %eax /* store pointer to iframe */
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pushl %eax
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call x86_exception_handler
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popl %eax /* drop pointer to iframe */
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popa /* restore general purpose registers */
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popl %ds /* restore segment registers */
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popl %es
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popl %fs
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popl %gs
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addl $8, %esp /* drop exception number and error code */
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iret
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FUNCTION(setup_idt)
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/* setup isr stub descriptors in the idt */
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movl $_isr, %esi
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movl $_idt, %edi
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movl $NUM_INT, %ecx
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.Lloop:
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movl %esi, %ebx
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movw %bx, (%edi) /* low word in IDT(n).low */
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shrl $16, %ebx
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movw %bx, 6(%edi) /* high word in IDT(n).high */
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addl $isr_stub_len, %esi/* index the next ISR stub */
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addl $8, %edi /* index the next IDT entry */
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loop .Lloop
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lidt _idtr
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ret
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.data
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.align 8
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.global _idtr
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_idtr:
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.short _idt_end - _idt - 1 /* IDT limit */
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.int _idt
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/* interrupt descriptor table (IDT) */
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.global _idt
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_idt:
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.set i, 0
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.rept NUM_INT-1
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.short 0 /* low 16 bits of ISR offset (_isr#i & 0FFFFh) */
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.short CODE_SELECTOR /* selector */
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.byte 0
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.byte 0x8e /* present, ring 0, 32-bit interrupt gate */
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.short 0 /* high 16 bits of ISR offset (_isr#i / 65536) */
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.set i, i + 1
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.endr
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/* syscall int (ring 3) */
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_idt30:
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.short 0 /* low 16 bits of ISR offset (_isr#i & 0FFFFh) */
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.short CODE_SELECTOR /* selector */
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.byte 0
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.byte 0xee /* present, ring 3, 32-bit interrupt gate */
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.short 0 /* high 16 bits of ISR offset (_isr#i / 65536) */
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.global _idt_end
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_idt_end:
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