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kernel_ldr: clean up KSystemControl init API
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@SciresM
SciresM committed Dec 31, 2019
1 parent d10621e commit bf5bbfb
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Showing 5 changed files with 102 additions and 62 deletions.
18 changes: 10 additions & 8 deletions libraries/libmesosphere/include/mesosphere/board/nintendo/switch/kern_k_system_control.hpp
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Expand Up @@ -20,15 +20,17 @@ namespace ams::kern {

class KSystemControl {
public:
class Init {
public:
/* Initialization. */
static KPhysicalAddress GetKernelPhysicalBaseAddress(uintptr_t base_address);
static bool ShouldIncreaseThreadResourceLimit();

/* Initialization. */
static KPhysicalAddress GetKernelPhysicalBaseAddress(uintptr_t base_address);
static bool ShouldIncreaseResourceRegionSize();

/* Randomness. */
static void GenerateRandomBytes(void *dst, size_t size);
static u64 GenerateRandomRange(u64 min, u64 max);

/* Randomness. */
static void GenerateRandomBytes(void *dst, size_t size);
static u64 GenerateRandomRange(u64 min, u64 max);
};
public:
/* Panic. */
static NORETURN void StopSystem();
};
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41 changes: 20 additions & 21 deletions libraries/libmesosphere/source/board/nintendo/switch/kern_k_system_control.cpp
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Expand Up @@ -25,33 +25,32 @@ namespace ams::kern {
constexpr size_t SixGigabytes = 0x180000000ul;
constexpr size_t EightGigabytes = 0x200000000ul;

size_t GetRealMemorySize() {
ALWAYS_INLINE size_t GetRealMemorySizeForInit() {
/* TODO: Move this into a header for the MC in general. */
constexpr u32 MemoryControllerConfigurationRegister = 0x70019050;
u32 config_value;
MESOSPHERE_ABORT_UNLESS(smc::ReadWriteRegister(&config_value, MemoryControllerConfigurationRegister, 0, 0));
MESOSPHERE_ABORT_UNLESS(smc::init::ReadWriteRegister(&config_value, MemoryControllerConfigurationRegister, 0, 0));
return static_cast<size_t>(config_value & 0x3FFF) << 20;
}

inline u64 GetKernelConfiguration() {
ALWAYS_INLINE u64 GetKernelConfigurationForInit() {
u64 value = 0;
smc::GetConfig(&value, 1, smc::ConfigItem::KernelConfiguration);
smc::init::GetConfig(&value, 1, smc::ConfigItem::KernelConfiguration);
return value;
}

inline u64 GenerateRandomU64() {
ALWAYS_INLINE u64 GenerateRandomU64ForInit() {
u64 value;
smc::GenerateRandomBytes(&value, sizeof(value));
smc::init::GenerateRandomBytes(&value, sizeof(value));
return value;
}

inline smc::MemoryMode GetMemoryMode() {
return static_cast<smc::MemoryMode>((GetKernelConfiguration() >> 10) & 0x3);
ALWAYS_INLINE smc::MemoryMode GetMemoryModeForInit() {
return static_cast<smc::MemoryMode>((GetKernelConfigurationForInit() >> 10) & 0x3);
}

size_t GetIntendedMemorySize() {
const smc::MemoryMode memory_mode = GetMemoryMode();
switch (memory_mode) {
ALWAYS_INLINE size_t GetIntendedMemorySizeForInit() {
switch (GetMemoryModeForInit()) {
case smc::MemoryMode_4GB:
default: /* All invalid modes should go to 4GB. */
return FourGigabytes;
Expand All @@ -65,31 +64,31 @@ namespace ams::kern {
}

/* Initialization. */
KPhysicalAddress KSystemControl::GetKernelPhysicalBaseAddress(uintptr_t base_address) {
const size_t real_dram_size = GetRealMemorySize();
const size_t intended_dram_size = GetIntendedMemorySize();
KPhysicalAddress KSystemControl::Init::GetKernelPhysicalBaseAddress(uintptr_t base_address) {
const size_t real_dram_size = GetRealMemorySizeForInit();
const size_t intended_dram_size = GetIntendedMemorySizeForInit();
if (intended_dram_size * 2 < real_dram_size) {
return base_address;
} else {
return base_address + ((real_dram_size - intended_dram_size) / 2);
}
}

bool KSystemControl::ShouldIncreaseResourceRegionSize() {
return (GetKernelConfiguration() >> 3) & 1;
bool KSystemControl::Init::ShouldIncreaseThreadResourceLimit() {
return (GetKernelConfigurationForInit() >> 3) & 1;
}

/* Randomness. */
void KSystemControl::GenerateRandomBytes(void *dst, size_t size) {
/* Randomness for Initialization. */
void KSystemControl::Init::GenerateRandomBytes(void *dst, size_t size) {
MESOSPHERE_ABORT_UNLESS(size <= 0x38);
smc::GenerateRandomBytes(dst, size);
smc::init::GenerateRandomBytes(dst, size);
}

u64 KSystemControl::GenerateRandomRange(u64 min, u64 max) {
u64 KSystemControl::Init::GenerateRandomRange(u64 min, u64 max) {
const u64 range_size = ((max + 1) - min);
const u64 effective_max = (std::numeric_limits<u64>::max() / range_size) * range_size;
while (true) {
if (const u64 rnd = GenerateRandomU64(); rnd < effective_max) {
if (const u64 rnd = GenerateRandomU64ForInit(); rnd < effective_max) {
return min + (rnd % range_size);
}
}
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80 changes: 57 additions & 23 deletions libraries/libmesosphere/source/board/nintendo/switch/kern_secure_monitor.cpp
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Expand Up @@ -69,27 +69,68 @@ namespace ams::kern::smc {
args.x[7] = x7;
}

}
void CallPrivilegedSecureMonitorFunctionForInit(SecureMonitorArguments &args) {
/* Load arguments into registers. */
register u64 x0 asm("x0") = args.x[0];
register u64 x1 asm("x1") = args.x[1];
register u64 x2 asm("x2") = args.x[2];
register u64 x3 asm("x3") = args.x[3];
register u64 x4 asm("x4") = args.x[4];
register u64 x5 asm("x5") = args.x[5];
register u64 x6 asm("x6") = args.x[6];
register u64 x7 asm("x7") = args.x[7];

void GetConfig(u64 *out, size_t num_qwords, ConfigItem config_item) {
SecureMonitorArguments args = { FunctionId_GetConfig, static_cast<u32>(config_item) };
CallPrivilegedSecureMonitorFunction(args);
MESOSPHERE_ABORT_UNLESS((static_cast<SmcResult>(args.x[0]) == SmcResult::Success));
for (size_t i = 0; i < num_qwords && i < 7; i++) {
out[i] = args.x[1 + i];
/* Actually make the call. */
__asm__ __volatile__("smc #1"
: "+r"(x0), "+r"(x1), "+r"(x2), "+r"(x3), "+r"(x4), "+r"(x5), "+r"(x6), "+r"(x7)
:
: "x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15", "x16", "x17", "x18", "cc", "memory"
);

/* Store arguments to output. */
args.x[0] = x0;
args.x[1] = x1;
args.x[2] = x2;
args.x[3] = x3;
args.x[4] = x4;
args.x[5] = x5;
args.x[6] = x6;
args.x[7] = x7;
}

}

void GenerateRandomBytes(void *dst, size_t size) {
/* Call SmcGenerateRandomBytes() */
/* TODO: Lock this to ensure only one core calls at once. */
SecureMonitorArguments args = { FunctionId_GenerateRandomBytes, size };
MESOSPHERE_ABORT_UNLESS(size <= sizeof(args) - sizeof(args.x[0]));
CallPrivilegedSecureMonitorFunction(args);
MESOSPHERE_ABORT_UNLESS((static_cast<SmcResult>(args.x[0]) == SmcResult::Success));
/* SMC functionality needed for init. */
namespace init {

void GetConfig(u64 *out, size_t num_qwords, ConfigItem config_item) {
SecureMonitorArguments args = { FunctionId_GetConfig, static_cast<u32>(config_item) };
CallPrivilegedSecureMonitorFunctionForInit(args);
MESOSPHERE_ABORT_UNLESS((static_cast<SmcResult>(args.x[0]) == SmcResult::Success));
for (size_t i = 0; i < num_qwords && i < 7; i++) {
out[i] = args.x[1 + i];
}
}

void GenerateRandomBytes(void *dst, size_t size) {
/* Call SmcGenerateRandomBytes() */
/* TODO: Lock this to ensure only one core calls at once. */
SecureMonitorArguments args = { FunctionId_GenerateRandomBytes, size };
MESOSPHERE_ABORT_UNLESS(size <= sizeof(args) - sizeof(args.x[0]));
CallPrivilegedSecureMonitorFunctionForInit(args);
MESOSPHERE_ABORT_UNLESS((static_cast<SmcResult>(args.x[0]) == SmcResult::Success));

/* Copy output. */
std::memcpy(dst, &args.x[1], size);
}

bool ReadWriteRegister(u32 *out, u64 address, u32 mask, u32 value) {
SecureMonitorArguments args = { FunctionId_ReadWriteRegister, address, mask, value };
CallPrivilegedSecureMonitorFunctionForInit(args);
*out = args.x[1];
return static_cast<SmcResult>(args.x[0]) == SmcResult::Success;
}

/* Copy output. */
std::memcpy(dst, &args.x[1], size);
}

void NORETURN Panic(u32 color) {
Expand All @@ -98,11 +139,4 @@ namespace ams::kern::smc {
while (true) { /* ... */ }
}

bool ReadWriteRegister(u32 *out, u64 address, u32 mask, u32 value) {
SecureMonitorArguments args = { FunctionId_ReadWriteRegister, address, mask, value };
CallPrivilegedSecureMonitorFunction(args);
*out = args.x[1];
return static_cast<SmcResult>(args.x[0]) == SmcResult::Success;
}

}
19 changes: 12 additions & 7 deletions libraries/libmesosphere/source/board/nintendo/switch/kern_secure_monitor.hpp
View file
Expand Up @@ -36,13 +36,13 @@ namespace ams::kern::smc {
IsRecoveryBoot = 7,
DeviceId = 8,
BootReason = 9,
MemoryArrange = 10,
MemoryMode = 10,
IsDebugMode = 11,
KernelConfiguration = 12,
IsChargerHiZModeEnabled = 13,
IsKiosk = 14,
NewHardwareType = 15,
NewKeyGeneration = 16,
IsQuest = 14,
RegulatorType = 15,
DeviceUniqueKeyGeneration = 16,
Package2Hash = 17,

/* Extension config items for exosphere. */
Expand All @@ -64,9 +64,14 @@ namespace ams::kern::smc {
};

/* TODO: Rest of Secure Monitor API. */
void GetConfig(u64 *out, size_t num_qwords, ConfigItem config_item);
void GenerateRandomBytes(void *dst, size_t size);
void NORETURN Panic(u32 color);
bool ReadWriteRegister(u32 *out, u64 address, u32 mask, u32 value);

namespace init {

void GetConfig(u64 *out, size_t num_qwords, ConfigItem config_item);
void GenerateRandomBytes(void *dst, size_t size);
bool ReadWriteRegister(u32 *out, u64 address, u32 mask, u32 value);

}

}
6 changes: 3 additions & 3 deletions mesosphere/kernel_ldr/source/kern_init_loader.cpp
View file
Expand Up @@ -66,7 +66,7 @@ namespace ams::kern::init::loader {

void RelocateKernelPhysically(uintptr_t &base_address, KernelLayout *&layout) {
/* TODO: Proper secure monitor call. */
KPhysicalAddress correct_base = KSystemControl::GetKernelPhysicalBaseAddress(base_address);
KPhysicalAddress correct_base = KSystemControl::Init::GetKernelPhysicalBaseAddress(base_address);
if (correct_base != base_address) {
const uintptr_t diff = GetInteger(correct_base) - base_address;
const size_t size = layout->rw_end_offset;
Expand Down Expand Up @@ -218,7 +218,7 @@ namespace ams::kern::init::loader {

/* Repeatedly generate a random virtual address until we get one that's unmapped in the destination page table. */
while (true) {
const KVirtualAddress random_kaslr_slide = KSystemControl::GenerateRandomRange(KernelBaseRangeMin, KernelBaseRangeEnd);
const KVirtualAddress random_kaslr_slide = KSystemControl::Init::GenerateRandomRange(KernelBaseRangeMin, KernelBaseRangeEnd);
const KVirtualAddress kernel_region_start = util::AlignDown(GetInteger(random_kaslr_slide), KernelBaseAlignment);
const KVirtualAddress kernel_region_end = util::AlignUp(GetInteger(kernel_region_start) + kernel_offset + kernel_size, KernelBaseAlignment);
const size_t kernel_region_size = GetInteger(kernel_region_end) - GetInteger(kernel_region_start);
Expand Down Expand Up @@ -275,7 +275,7 @@ namespace ams::kern::init::loader {
const uintptr_t init_array_end_offset = layout->init_array_end_offset;

/* Decide if Kernel should have enlarged resource region. */
const bool use_extra_resources = KSystemControl::ShouldIncreaseResourceRegionSize();
const bool use_extra_resources = KSystemControl::Init::ShouldIncreaseThreadResourceLimit();
const size_t resource_region_size = KernelResourceRegionSize + (use_extra_resources ? ExtraKernelResourceSize : 0);

/* Setup the INI1 header in memory for the kernel. */
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