2597e2002b
* It looks like UEFI enables SSE, so we need to tell clang -mno-sse for now to not use XMM* until we're ready to save them. * SYSCALL is working from ring3 tasks, calling console printf!
213 lines
2.8 KiB
ArmAsm
213 lines
2.8 KiB
ArmAsm
extern g_idtr
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extern g_gdtr
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global idt_write
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idt_write:
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lidt [rel g_idtr]
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ret
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global idt_load
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idt_load:
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sidt [rel g_idtr]
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ret
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global gdt_write
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gdt_write:
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lgdt [rel g_gdtr]
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mov ax, si ; second arg is data segment
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mov ds, ax
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mov es, ax
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mov fs, ax
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mov gs, ax
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mov ss, ax
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push qword rdi ; first arg is code segment
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lea rax, [rel .next]
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push rax
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o64 retf
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.next:
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ltr dx
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ret
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global gdt_load
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gdt_load:
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sgdt [rel g_gdtr]
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ret
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%macro push_all_and_segments 0
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push rax
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push rcx
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push rdx
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push rbx
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push rbp
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push rsi
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push rdi
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push r8
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push r9
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push r10
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push r11
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push r12
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push r13
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push r14
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push r15
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mov ax, ds
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push rax
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%endmacro
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%macro pop_all_and_segments 0
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pop rax
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mov ds, ax
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mov es, ax
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mov fs, ax
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mov gs, ax
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pop r15
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pop r14
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pop r13
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pop r12
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pop r11
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pop r10
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pop r9
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pop r8
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pop rdi
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pop rsi
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pop rbp
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pop rbx
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pop rdx
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pop rcx
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pop rax
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%endmacro
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extern isr_handler
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global isr_handler_prelude
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isr_handler_prelude:
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push_all_and_segments
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mov rdi, rsp
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call isr_handler
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mov rsp, rax
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pop_all_and_segments
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add rsp, 16 ; because the ISRs added err/num
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sti
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iretq
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extern irq_handler
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global irq_handler_prelude
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irq_handler_prelude:
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push_all_and_segments
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call irq_handler
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pop_all_and_segments
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add rsp, 16 ; because the ISRs added err/num
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sti
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iretq
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%macro EMIT_ISR 2
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global %1
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%1:
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cli
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push 0
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push %2
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jmp isr_handler_prelude
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%endmacro
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%macro EMIT_EISR 2
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global %1
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%1:
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cli
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push %2
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jmp isr_handler_prelude
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%endmacro
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%macro EMIT_IRQ 2
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global %1
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%1:
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cli
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push 0
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push %2
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jmp irq_handler_prelude
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%endmacro
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%define EISR(i, name) EMIT_EISR name, i
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%define ISR(i, name) EMIT_ISR name, i
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%define IRQ(i, q, name) EMIT_IRQ name, i
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section .isrs
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%include "interrupt_isrs.inc"
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extern syscall_handler
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syscall_handler_prelude:
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push 0 ; ss, doesn't matter here
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push rsp
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pushf
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push 0 ; cs, doesn't matter here
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push rcx ; user rip
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push 0 ; bogus interrupt
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push 0 ; bogus errorcode
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push_all_and_segments
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call syscall_handler
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pop_all_and_segments
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add rsp, 16 ; ignore bogus interrupt / error
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pop rcx ; user rip
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add rsp, 32 ; ignore cs, flags, rsp, ss
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o64 sysret
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global syscall_enable
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syscall_enable:
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; IA32_EFER - set bit 0, syscall enable
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mov rcx, 0xc0000080
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rdmsr
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or rax, 0x1
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wrmsr
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; IA32_STAR - cs for syscall
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mov rcx, 0xc0000081
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mov rax, 0 ; not used
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mov rdx, 0x00180008 ; GDT:3 (user code), GDT:1 (kernel code)
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wrmsr
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; IA32_LSTAR - RIP for syscall
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mov rcx, 0xc0000082
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lea rax, [rel syscall_handler_prelude]
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mov rdx, rax
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shr rdx, 32
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wrmsr
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; IA32_FMASK - FLAGS mask inside syscall
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mov rcx, 0xc0000084
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mov rax, 0x200
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mov rdx, 0
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wrmsr
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ret
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global taskA
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taskA:
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push rbp
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mov rbp, rsp
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mov rax, 0xaaaaaaaaaaaaaaaa
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.loop:
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syscall
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jmp .loop
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global taskB
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taskB:
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push rbp
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mov rbp, rsp
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mov rax, 0xbbbbbbbbbbbbbbbb
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.loop:
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syscall
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jmp .loop
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