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ncm: loosen FirmwareVariation restrictions.

This commit is contained in:
Michael Scire 2020-07-10 11:46:45 -07:00
parent c2408395d8
commit ad551c3b55
2 changed files with 22 additions and 6 deletions

View file

@ -64,7 +64,7 @@ namespace ams::ncm {
};
struct SystemUpdateMetaExtendedDataHeader {
u32 unk; // Always seems to be set to 2
u32 version;
u32 firmware_variation_count;
};

View file

@ -94,8 +94,7 @@ namespace ams::ncm {
PackagedContentMetaReader reader(meta.Get(), meta.GetSize());
/* Define a helper to output the base meta infos. */
/* TODO: C++20 ALWAYS_INLINE_LAMBDA */
const auto ReadMetaInfoListFromBase = [&]() -> Result {
const auto ReadMetaInfoListFromBase = [&] ALWAYS_INLINE_LAMBDA () -> Result {
/* Output the base content meta info count. */
*out_count = reader.GetContentMetaCount();
@ -119,22 +118,39 @@ namespace ams::ncm {
SystemUpdateMetaExtendedDataReader extended_data_reader(reader.GetExtendedData(), reader.GetExtendedDataSize());
std::optional<s32> firmware_variation_index = std::nullopt;
/* NOTE: Atmosphere extension to support downgrading. */
/* If all firmware variations refer to base, don't require the current variation be present. */
bool force_refer_to_base = true;
/* Find the input firmware variation id. */
for (size_t i = 0; i < extended_data_reader.GetFirmwareVariationCount(); i++) {
if (*extended_data_reader.GetFirmwareVariationId(i) == firmware_variation_id) {
firmware_variation_index = i;
break;
} else {
/* Check if the current variation refers to base. */
const FirmwareVariationInfo *cur_variation_info = extended_data_reader.GetFirmwareVariationInfo(i);
const bool cur_refers_to_base = cur_variation_info->refer_to_base || extended_data_reader.GetHeader()->version == 1;
/* We force referral to base on unsupported variation only if all supported variations refer to base. */
force_refer_to_base &= cur_refers_to_base;
}
}
/* We couldn't find the input firmware variation id. */
R_UNLESS(firmware_variation_index, ncm::ResultInvalidFirmwareVariation());
if (!firmware_variation_index) {
/* Unless we can force a referral to base, the firmware isn't supported. */
R_UNLESS(force_refer_to_base, ncm::ResultInvalidFirmwareVariation());
/* Force a referral to base. */
return ReadMetaInfoListFromBase();
}
/* Obtain the variation info. */
const FirmwareVariationInfo *variation_info = extended_data_reader.GetFirmwareVariationInfo(*firmware_variation_index);
/* Refer to base if variation info says we should, or if unk is 1 (unk is usually 2, probably a version). */
const bool refer_to_base = variation_info->refer_to_base || extended_data_reader.GetHeader()->unk == 1;
/* Refer to base if variation info says we should, or if version is 1. */
const bool refer_to_base = variation_info->refer_to_base || extended_data_reader.GetHeader()->version == 1;
R_UNLESS(!refer_to_base, ReadMetaInfoListFromBase());
/* Output the content meta count. */