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Add NonCacheable DRAM mapping for VC framebuffer area

This commit is contained in:
Berkus Decker 2019-02-24 18:34:37 +02:00
parent a34153028c
commit 98be0a304c
1 changed files with 22 additions and 12 deletions
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34
src/arch/aarch64/mmu.rs
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@ -124,26 +124,31 @@ static mut SINGLE_LVL3_TABLE: PageTable = PageTable {
entries: [0; NUM_ENTRIES_4KIB],
};
/// Set up identity mapped page tables for the first 1 gigabyte of address
/// space.
/// Set up identity mapped page tables for the first 1 gigabyte of address space.
/// default: 880 MB ARM ram, 128MB VC
pub unsafe fn init() {
print_features();
// First, define the two memory types that we will map. Normal DRAM and
// device.
// First, define the three memory types that we will map. Normal DRAM, Uncached and device.
MAIR_EL1.write(
// Attribute 1
MAIR_EL1::Attr1_HIGH::Device
+ MAIR_EL1::Attr1_LOW_DEVICE::Device_nGnRE
// Attribute 2
MAIR_EL1::Attr2_HIGH::Device
+ MAIR_EL1::Attr2_LOW_DEVICE::Device_nGnRE
// Attribute 1
+ MAIR_EL1::Attr1_HIGH::Memory_OuterNonCacheable
+ MAIR_EL1::Attr1_LOW_MEMORY::InnerNonCacheable
// Attribute 0
+ MAIR_EL1::Attr0_HIGH::Memory_OuterWriteBack_NonTransient_ReadAlloc_WriteAlloc
+ MAIR_EL1::Attr0_LOW_MEMORY::InnerWriteBack_NonTransient_ReadAlloc_WriteAlloc,
);
// Two descriptive consts for indexing into the correct MAIR_EL1 attributes.
// Three descriptive consts for indexing into the correct MAIR_EL1 attributes.
mod mair {
pub const NORMAL: u64 = 0;
pub const DEVICE: u64 = 1;
pub const NORMAL_NC: u64 = 1;
pub const DEVICE_NGNRE: u64 = 2;
// DEVICE_GRE
// DEVICE_NGNRNE
}
// Set up the first LVL2 entry, pointing to a 4KiB table base address.
@ -158,7 +163,7 @@ pub unsafe fn init() {
let uart_phys_base: u64 = (crate::platform::mini_uart::UART1_BASE >> 21).into();
LVL2_TABLE.entries[1] = (STAGE1_DESCRIPTOR::VALID::True
+ STAGE1_DESCRIPTOR::TYPE::Block
+ STAGE1_DESCRIPTOR::AttrIndx.val(mair::DEVICE)
+ STAGE1_DESCRIPTOR::AttrIndx.val(mair::DEVICE_NGNRE)
+ STAGE1_DESCRIPTOR::AP::RW_EL1
+ STAGE1_DESCRIPTOR::SH::OuterShareable
+ STAGE1_DESCRIPTOR::AF::True
@ -167,7 +172,9 @@ pub unsafe fn init() {
.value;
// Fill the rest of the LVL2 (2MiB) entries as block
// descriptors. Differentiate between normal and device mem.
// descriptors. Differentiate between normal, VC and device mem.
let vc_base: u64 = (0x3700_0000u32 >> 21).into();
let mmio_base: u64 = (crate::platform::rpi3::BcmHost::get_peripheral_address() >> 21).into();
let common = STAGE1_DESCRIPTOR::VALID::True
+ STAGE1_DESCRIPTOR::TYPE::Block
@ -180,7 +187,10 @@ pub unsafe fn init() {
let j: u64 = i as u64;
let mem_attr = if j >= mmio_base {
STAGE1_DESCRIPTOR::SH::OuterShareable + STAGE1_DESCRIPTOR::AttrIndx.val(mair::DEVICE)
STAGE1_DESCRIPTOR::SH::OuterShareable
+ STAGE1_DESCRIPTOR::AttrIndx.val(mair::DEVICE_NGNRE)
} else if j >= vc_base {
STAGE1_DESCRIPTOR::SH::OuterShareable + STAGE1_DESCRIPTOR::AttrIndx.val(mair::NORMAL_NC)
} else {
STAGE1_DESCRIPTOR::SH::InnerShareable + STAGE1_DESCRIPTOR::AttrIndx.val(mair::NORMAL)
};