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Kernel: ACPI code doesn't rely on identity mapping anymore

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The problem was mostly in the initialization code, since in that stage
the parser assumed that there is an identity mapping in the first 1MB of
the address space. Now during initialization the parser will create the
correct mappings to locate the required data.
This commit is contained in:
Liav A 2020-01-21 04:37:30 +02:00 • committed by Andreas Kling
parent 325022cbd7
commit 60c32f44dd
2 changed files with 45 additions and 24 deletions
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67
Kernel/ACPI/ACPIStaticParser.cpp
View file

@ -212,19 +212,21 @@ void ACPIStaticParser::initialize_main_system_description_table()
void ACPIStaticParser::locate_main_system_description_table()
{
if (m_rsdp->base.revision == 0) {
auto rsdp_region = MM.allocate_kernel_region(PhysicalAddress(page_base_of((u32)m_rsdp)), (PAGE_SIZE * 2), "ACPI Static Parser Initialization", Region::Access::Read, false, true);
volatile auto* rsdp = (ACPI_RAW::RSDPDescriptor20*)rsdp_region->vaddr().offset(offset_in_page((u32)m_rsdp)).as_ptr();
if (rsdp->base.revision == 0) {
m_xsdt_supported = false;
} else if (m_rsdp->base.revision >= 2) {
if (m_rsdp->xsdt_ptr != (u64) nullptr) {
} else if (rsdp->base.revision >= 2) {
if (rsdp->xsdt_ptr != (u64) nullptr) {
m_xsdt_supported = true;
} else {
m_xsdt_supported = false;
}
}
if (!m_xsdt_supported) {
m_main_system_description_table = (ACPI_RAW::SDTHeader*)m_rsdp->base.rsdt_ptr;
m_main_system_description_table = (ACPI_RAW::SDTHeader*)rsdp->base.rsdt_ptr;
} else {
m_main_system_description_table = (ACPI_RAW::SDTHeader*)m_rsdp->xsdt_ptr;
m_main_system_description_table = (ACPI_RAW::SDTHeader*)rsdp->xsdt_ptr;
}
}
@ -265,30 +267,47 @@ ACPIStaticParser::ACPIStaticParser()
}
}
ACPI_RAW::RSDPDescriptor20* ACPIStaticParser::search_rsdp_in_ebda(u16 ebda_segment)
{
auto rsdp_region = MM.allocate_kernel_region(PhysicalAddress(page_base_of((u32)(ebda_segment << 4))), PAGE_ROUND_UP(1024), "ACPI Static Parser RSDP Finding #1", Region::Access::Read, false, true);
char* p_rsdp_str = (char*)(PhysicalAddress(ebda_segment << 4).as_ptr());
for (char* rsdp_str = (char*)rsdp_region->vaddr().offset(offset_in_page((u32)(ebda_segment << 4))).as_ptr(); rsdp_str < (char*)(rsdp_region->vaddr().offset(offset_in_page((u32)(ebda_segment << 4))).get() + 1024); rsdp_str += 16) {
#ifdef ACPI_DEBUG
dbgprintf("ACPI: Looking for RSDP in EBDA @ V0x%x, P0x%x\n", rsdp_str, p_rsdp_str);
#endif
if (!strncmp("RSD PTR ", rsdp_str, strlen("RSD PTR ")))
return (ACPI_RAW::RSDPDescriptor20*)p_rsdp_str;
p_rsdp_str += 16;
}
return nullptr;
}
ACPI_RAW::RSDPDescriptor20* ACPIStaticParser::search_rsdp_in_bios_area()
{
auto rsdp_region = MM.allocate_kernel_region(PhysicalAddress(page_base_of((u32)0xE0000)), PAGE_ROUND_UP(0xFFFFF - 0xE0000), "ACPI Static Parser RSDP Finding #2", Region::Access::Read, false, true);
char* p_rsdp_str = (char*)(PhysicalAddress(0xE0000).as_ptr());
for (char* rsdp_str = (char*)rsdp_region->vaddr().offset(offset_in_page((u32)(0xE0000))).as_ptr(); rsdp_str < (char*)(rsdp_region->vaddr().offset(offset_in_page((u32)(0xE0000))).get() + (0xFFFFF - 0xE0000)); rsdp_str += 16) {
#ifdef ACPI_DEBUG
dbgprintf("ACPI: Looking for RSDP in EBDA @ V0x%x, P0x%x\n", rsdp_str, p_rsdp_str);
#endif
if (!strncmp("RSD PTR ", rsdp_str, strlen("RSD PTR ")))
return (ACPI_RAW::RSDPDescriptor20*)p_rsdp_str;
p_rsdp_str += 16;
}
return nullptr;
}
ACPI_RAW::RSDPDescriptor20* ACPIStaticParser::search_rsdp()
{
auto region = MM.allocate_kernel_region(PhysicalAddress((uintptr_t)0), PAGE_SIZE, "ACPI Static Parser RSDP Finding", Region::Access::Read);
ACPI_RAW::RSDPDescriptor20* rsdp = nullptr;
auto region = MM.allocate_kernel_region(PhysicalAddress(0), PAGE_SIZE, "ACPI Static Parser RSDP Finding", Region::Access::Read);
u16 ebda_seg = (u16) * ((uint16_t*)((region->vaddr().get() & PAGE_MASK) + 0x40e));
kprintf("ACPI: Probing EBDA, Segment 0x%x\n", ebda_seg);
// FIXME: Ensure that we always have identity mapping (identity paging) here! Don't rely on existing mapping...
for (char* rsdp_str = (char*)(PhysicalAddress(ebda_seg << 4).as_ptr()); rsdp_str < (char*)((ebda_seg << 4) + 1024); rsdp_str += 16) {
#ifdef ACPI_DEBUG
dbgprintf("ACPI: Looking for RSDP in EBDA @ Px%x\n", rsdp_str);
#endif
if (!strncmp("RSD PTR ", rsdp_str, strlen("RSD PTR ")))
return (ACPI_RAW::RSDPDescriptor20*)rsdp_str;
}
// FIXME: Ensure that we always have identity mapping (identity paging) here! Don't rely on existing mapping...
for (char* rsdp_str = (char*)(PhysicalAddress(0xE0000).as_ptr()); rsdp_str < (char*)0xFFFFF; rsdp_str += 16) {
#ifdef ACPI_DEBUG
dbgprintf("ACPI: Looking for RSDP in EBDA @ Px%x\n", rsdp_str);
#endif
if (!strncmp("RSD PTR ", rsdp_str, strlen("RSD PTR ")))
return (ACPI_RAW::RSDPDescriptor20*)rsdp_str;
}
return nullptr;
rsdp = search_rsdp_in_ebda(ebda_seg);
if (rsdp != nullptr)
return rsdp;
return search_rsdp_in_bios_area();
}
ACPIStaticParser::ACPIStaticParser(ACPI_RAW::RSDPDescriptor20& rsdp)

2
Kernel/ACPI/ACPIStaticParser.h
View file

@ -52,6 +52,8 @@ private:
size_t get_table_size(ACPI_RAW::SDTHeader&);
u8 get_table_revision(ACPI_RAW::SDTHeader&);
void init_fadt();
ACPI_RAW::RSDPDescriptor20* search_rsdp_in_ebda(u16 ebda_segment);
ACPI_RAW::RSDPDescriptor20* search_rsdp_in_bios_area();
ACPI_RAW::RSDPDescriptor20* search_rsdp();
// Early pointers that are needed really for initializtion only...