rulimine/common/sys/smp_trampoline.asm_aarch64
2023-07-26 23:13:33 +02:00

148 lines
2.7 KiB
Plaintext

#include <lib/macros.aarch64_asm.h>
.set tpl_booted_flag, -64
.set tpl_hhdm_offset, -56
.set tpl_ttbr0, -48
.set tpl_ttbr1, -40
.set tpl_mair, -32
.set tpl_tcr, -24
.set tpl_sctlr, -16
.set tpl_info_struct, -8
.section .text
.global smp_trampoline_start
smp_trampoline_start:
bl .L_entry
.L_entry:
// Mask IRQs
msr daifset, #0b1111
// Address to next page (since our offsets into the boot data are negative)
add x1, x30, #0xFFC
ldr x0, [x1, tpl_info_struct]
ldr x2, [x1, tpl_sctlr]
ldr x3, [x1, tpl_mair]
ldr x4, [x1, tpl_tcr]
ldr x5, [x1, tpl_ttbr0]
ldr x6, [x1, tpl_ttbr1]
ldr x7, [x1, tpl_hhdm_offset]
PICK_EL x8, 1f, 0f
0:
// Configure EL2-specific state for EL1
// Configure EL1 page tables
msr mair_el1, x3
msr tcr_el1, x4
msr ttbr0_el1, x5
msr ttbr1_el1, x6
msr sctlr_el1, x2
isb
dsb sy
isb
// Don't trap counters to EL2
mrs x8, cnthctl_el2
orr x8, x8, #3
msr cnthctl_el2, x8
msr cntvoff_el2, xzr
// Enable AArch64 in EL1
mov x8, xzr
orr x8, x8, #(1 << 31)
orr x8, x8, #(1 << 1)
msr hcr_el2, x8
// Don't trap FP/SIMD to EL2
mov x8, #0x33FF
msr cptr_el2, x8
msr hstr_el2, xzr
// Run rest of trampoline in EL1
mov x8, #0x3c4
msr spsr_el2, x8
adrp x8, 3f
add x8, x8, :lo12:2f
add x8, x8, x7 // Add HHDM offset
msr elr_el2, x8
eret
1:
msr spsel, #0
// Switch to the new page tables
// Point the EL1t handler to the continuation, such that after we page fault,
// execution continues as expected.
adrp x8, 2f
add x8, x8, #:lo12:2f
add x8, x8, x7
msr vbar_el1, x8
isb
dsb sy
isb
// Switch the page table registers
msr mair_el1, x3
msr tcr_el1, x4
msr ttbr0_el1, x5
msr ttbr1_el1, x6
msr sctlr_el1, x2
isb
dsb sy
isb
// Jump to the higher half mapping in case we didn't immediately crash
br x8
// Alignment required by VBAR register
.align 11
2:
// Zero out VBAR to avoid confusion
msr vbar_el1, xzr
3:
// Add HHDM offset to data pointer
add x1, x1, x7
// Notify BSP we are alive
mov x8, #1
add x9, x1, tpl_booted_flag
stlr x8, [x9]
// Wait for BSP to tell us where to go
// Add HHDM offset to our info struct pointer
add x0, x0, x7
add x9, x0, #24
4:
ldar x8, [x9]
cbnz x8, 5f
yield
b 4b
5:
msr elr_el1, x8
msr spsel, #0
ldr x8, [x0, #16]
mov sp, x8
// Enter kernel
mov x8, #0x3c4
msr spsr_el1, x8
ZERO_REGS_EXCEPT_X0
eret
smp_trampoline_end:
.section .rodata
.global smp_trampoline_size
smp_trampoline_size:
.quad smp_trampoline_end - smp_trampoline_start