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| author | Andrew Turner <andrew@FreeBSD.org> | 2020-12-23 07:24:07 +0000 |
|---|---|---|
| committer | Andrew Turner <andrew@FreeBSD.org> | 2020-12-23 07:54:59 +0000 |
| commit | 659f1a6aad04adf0a0d27415f7a967d231ce4cfb (patch) | |
| tree | 9850e724225851ea97972e7ba41caccf31dad852 /sys | |
| parent | 906a73e791a005e228c1e3c9f8cb1e581359c786 (diff) | |
| download | src-test-659f1a6aad04adf0a0d27415f7a967d231ce4cfb.tar.gz src-test-659f1a6aad04adf0a0d27415f7a967d231ce4cfb.zip | |
Improve address generation in the early arm64 boot
The adr instruction allows for an address of +-1M from the instruction.
If we replace these with an adrp and an add instruction we can generate
an address +-4G. The adrp will get an address of the 4k page the label
is within, and the add uses the :lo12: prefix to add just the low bits
to this address.
This will allow us to move things around with fewer issues than if we
needed to keep them within the +-1MB range.
Sponsored by: Innovate UK
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/arm64/arm64/locore.S | 33 |
1 files changed, 22 insertions, 11 deletions
diff --git a/sys/arm64/arm64/locore.S b/sys/arm64/arm64/locore.S index f438865a961a8..6f8d007b2efad 100644 --- a/sys/arm64/arm64/locore.S +++ b/sys/arm64/arm64/locore.S @@ -127,7 +127,8 @@ _start: bl start_mmu /* Load the new ttbr0 pagetable */ - adr x27, pagetable_l0_ttbr0 + adrp x27, pagetable_l0_ttbr0 + add x27, x27, :lo12:pagetable_l0_ttbr0 /* Jump to the virtual address space */ ldr x15, .Lvirtdone @@ -135,7 +136,8 @@ _start: virtdone: /* Set up the stack */ - adr x25, initstack_end + adrp x25, initstack_end + add x25, x25, :lo12:initstack_end mov sp, x25 sub sp, sp, #PCB_SIZE @@ -163,7 +165,8 @@ virtdone: str x1, [x0, #BP_MODULEP] str x26, [x0, #BP_KERN_L1PT] str x29, [x0, #BP_KERN_DELTA] - adr x25, initstack + adrp x25, initstack + add x25, x25, :lo12:initstack str x25, [x0, #BP_KERN_STACK] str x24, [x0, #BP_KERN_L0PT] str x27, [x0, #BP_KERN_TTBR0] @@ -206,15 +209,18 @@ ENTRY(mpentry) msr contextidr_el1, xzr /* Load the kernel page table */ - adr x24, pagetable_l0_ttbr1 + adrp x24, pagetable_l0_ttbr1 + add x24, x24, :lo12:pagetable_l0_ttbr1 /* Load the identity page table */ - adr x27, pagetable_l0_ttbr0_boostrap + adrp x27, pagetable_l0_ttbr0_boostrap + add x27, x27, :lo12:pagetable_l0_ttbr0_boostrap /* Enable the mmu */ bl start_mmu /* Load the new ttbr0 pagetable */ - adr x27, pagetable_l0_ttbr0 + adrp x27, pagetable_l0_ttbr0 + add x27, x27, :lo12:pagetable_l0_ttbr0 /* Jump to the virtual address space */ ldr x15, =mp_virtdone @@ -282,7 +288,8 @@ drop_to_el1: msr cntvoff_el2, xzr /* Hypervisor trap functions */ - adr x2, hyp_vectors + adrp x2, hyp_vectors + add x2, x2, :lo12:hyp_vectors msr vbar_el2, x2 mov x2, #(PSR_F | PSR_I | PSR_A | PSR_D | PSR_M_EL1h) @@ -345,7 +352,8 @@ hyp_vectors: */ get_virt_delta: /* Load the physical address of virt_map */ - adr x29, virt_map + adrp x29, virt_map + add x29, x29, :lo12:virt_map /* Load the virtual address of virt_map stored in virt_map */ ldr x28, [x29] /* Find PA - VA as PA' = VA' - VA + PA = VA' + (PA - VA) = VA' + x29 */ @@ -383,9 +391,11 @@ create_pagetables: mov x5, x30 /* Clean the page table */ - adr x6, pagetable + adrp x6, pagetable + add x6, x6, :lo12:pagetable mov x26, x6 - adr x27, pagetable_end + adrp x27, pagetable_end + add x27, x27, :lo12:pagetable_end 1: stp xzr, xzr, [x6], #16 stp xzr, xzr, [x6], #16 @@ -474,7 +484,8 @@ common: /* Link the DMAP tables */ ldr x8, =DMAP_MIN_ADDRESS - adr x9, pagetable_dmap; + adrp x9, pagetable_dmap + add x9, x9, :lo12:pagetable_dmap mov x10, #DMAP_TABLES bl link_l0_pagetable |