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kern/ldr: move crt0 into .rodata

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Michael Scire 2023-10-11 02:59:41 -07:00 • committed by SciresM
parent 4ca3c44e5f
commit 0daef4a6e8
7 changed files with 220 additions and 90 deletions
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34
mesosphere/kernel_ldr/source/kern_init_loader.cpp
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@ -50,6 +50,25 @@ namespace ams::kern::init::loader {
constinit void *g_final_state[2];
void RelocateKernelPhysically(uintptr_t &base_address, KernelLayout *&layout) {
/* Adjust layout to be correct. */
{
const ptrdiff_t layout_offset = reinterpret_cast<uintptr_t>(layout) - base_address;
layout->rx_offset += layout_offset;
layout->rx_end_offset += layout_offset;
layout->ro_offset += layout_offset;
layout->ro_end_offset += layout_offset;
layout->rw_offset += layout_offset;
layout->rw_end_offset += layout_offset;
layout->bss_offset += layout_offset;
layout->bss_end_offset += layout_offset;
layout->resource_offset += layout_offset;
layout->dynamic_offset += layout_offset;
layout->init_array_offset += layout_offset;
layout->init_array_end_offset += layout_offset;
layout->sysreg_offset += layout_offset;
}
/* Relocate the kernel if necessary. */
KPhysicalAddress correct_base = KSystemControl::Init::GetKernelPhysicalBaseAddress(base_address);
if (correct_base != base_address) {
const uintptr_t diff = GetInteger(correct_base) - base_address;
@ -62,7 +81,7 @@ namespace ams::kern::init::loader {
}
}
void SetupInitialIdentityMapping(KInitialPageTable &init_pt, uintptr_t base_address, uintptr_t kernel_size, uintptr_t page_table_region, size_t page_table_region_size, KInitialPageAllocator &allocator) {
void SetupInitialIdentityMapping(KInitialPageTable &init_pt, uintptr_t base_address, uintptr_t kernel_size, uintptr_t page_table_region, size_t page_table_region_size, KInitialPageAllocator &allocator, KernelSystemRegisters *sysregs) {
/* Map in an RWX identity mapping for the kernel. */
constexpr PageTableEntry KernelRWXIdentityAttribute(PageTableEntry::Permission_KernelRWX, PageTableEntry::PageAttribute_NormalMemory, PageTableEntry::Shareable_InnerShareable, PageTableEntry::MappingFlag_Mapped);
init_pt.Map(base_address, kernel_size, base_address, KernelRWXIdentityAttribute, allocator, 0);
@ -96,9 +115,17 @@ namespace ams::kern::init::loader {
/* Setup SCTLR_EL1. */
/* TODO: Define these bits properly elsewhere, document exactly what each bit set is doing .*/
constexpr u64 SctlrValue = 0x0000000034D5D925ul;
constexpr u64 SctlrValue = 0x0000000034D5D92Dul;
cpu::SetSctlrEl1(SctlrValue);
cpu::InstructionMemoryBarrier();
/* Setup the system registers for other cores. */
/* NOTE: sctlr_el1 on other cores has the WXN bit set (0x80000); this will be set before KernelMain() on this core. */
sysregs->ttbr0_el1 = init_pt.GetTtbr0L1TableAddress();
sysregs->ttbr1_el1 = init_pt.GetTtbr1L1TableAddress();
sysregs->tcr_el1 = TcrValue;
sysregs->mair_el1 = MairValue;
sysregs->sctlr_el1 = SctlrValue | 0x80000;
}
KVirtualAddress GetRandomKernelBaseAddress(KInitialPageTable &page_table, KPhysicalAddress phys_base_address, size_t kernel_size) {
@ -159,6 +186,7 @@ namespace ams::kern::init::loader {
const uintptr_t dynamic_offset = layout->dynamic_offset;
const uintptr_t init_array_offset = layout->init_array_offset;
const uintptr_t init_array_end_offset = layout->init_array_end_offset;
const uintptr_t sysreg_offset = layout->sysreg_offset;
/* Determine the size of the resource region. */
const size_t resource_region_size = KMemoryLayout::GetResourceRegionSizeForInit(KSystemControl::Init::ShouldIncreaseThreadResourceLimit());
@ -199,7 +227,7 @@ namespace ams::kern::init::loader {
KInitialPageTable init_pt(KernelBaseRangeStart, KernelBaseRangeLast, g_initial_page_allocator);
/* Setup initial identity mapping. TTBR1 table passed by reference. */
SetupInitialIdentityMapping(init_pt, base_address, bss_end_offset, resource_end_address, InitialPageTableRegionSizeMax, g_initial_page_allocator);
SetupInitialIdentityMapping(init_pt, base_address, bss_end_offset, resource_end_address, InitialPageTableRegionSizeMax, g_initial_page_allocator, reinterpret_cast<KernelSystemRegisters *>(base_address + sysreg_offset));
/* Generate a random slide for the kernel's base address. */
const KVirtualAddress virtual_base_address = GetRandomKernelBaseAddress(init_pt, base_address, bss_end_offset);