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// exported symbols from asm/linker.
// They are always unsafe.
extern "C" {
fn ___KERNEL_PM_START__();
fn ___KERNEL_PM_END__();
fn ___BSS_PM_START__();
fn ___BSS_PM_END__();
}
pub fn pmap_kernel_start() -> u64 {
return ___KERNEL_PM_START__ as u64;
}
pub fn pmap_kernel_end() -> u64 {
return ___KERNEL_PM_END__ as u64;
}
pub fn pmap_bss_start() -> u64 {
return ___BSS_PM_START__ as u64;
}
pub fn pmap_bss_end() -> u64 {
return ___BSS_PM_END__ as u64;
}
pub fn roundup_4k(addr: u64) -> u64 {
return (addr + 0xfff) & !0xfff;
}
pub fn rounddown_4k(addr: u64) -> u64 {
return addr & !0xfff;
}
pub struct Mem;
impl Mem {
// units
pub const K: u64 = 1024;
pub const M: u64 = 1024 * Mem::K;
pub const G: u64 = 1024 * Mem::M;
// physical memory layout: qemu defaults to 128 MiB phy Memory
pub const PHY_TOP: u64 = 128 * Mem::M;
// 4 lv 4K paging
pub const PAGE_SIZE: u64 = 0x1000;
pub const PAGE_SHIFT: u64 = 12;
pub const PAGE_MASK: u64 = 0xfff;
pub const L0_SHIFT: u8 = 39;
pub const L0_MASK: u64 = 0x1ff << Mem::L0_SHIFT;
pub const L1_SHIFT: u8 = 30;
pub const L1_MASK: u64 = 0x1ff << Mem::L1_SHIFT;
pub const L2_SHIFT: u8 = 21;
pub const L2_MASK: u64 = 0x1ff << Mem::L2_SHIFT;
pub const L3_SHIFT: u8 = 12;
pub const L3_MASK: u64 = 0x1ff << Mem::L3_SHIFT;
pub const PHY_PAGES: u64 = Mem::PHY_TOP >> Mem::PAGE_SHIFT;
// size of frame allocator bitmap: number of physical frames / 8 for 128M
// memory (37268) 4k pages, 37268 bits are needed, hence
// 4096 bytes, exactly one page!
pub const PHY_BM_SIZE: u64 = Mem::PHY_PAGES >> 3;
}
// PHY_TOP 128M
// ~ free frames
// PMA::bitmap + PHY_BM_SIZE
// ~ ___KERNEL_END__
// KERNEL IMAGE
// KERNEL START 1 M
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