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Clean up Multiboot a bit

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Thanks to Aimee for helping out with figuring out the iterator.
This commit is contained in:
Eryn Wells 2016-03-20 03:37:20 -04:00
parent 2b39ac909e
commit 9c5460c1f5
2 changed files with 47 additions and 76 deletions
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45
src/Multiboot.cc
View file

@ -53,35 +53,35 @@ Information::setInformation(Information *info)
*/
Information::MemoryMapIterator::MemoryMapIterator(uint32_t address,
uint32_t count)
: mCurrent(reinterpret_cast<MemoryChunk *>(address)),
mCount(count)
uint32_t length)
: mCurrent(address),
mLength(length)
{ }
Information::MemoryMapIterator::MemoryMapIterator(const MemoryMapIterator& other)
: mCurrent(other.mCurrent),
mCount(other.mCount)
mLength(other.mLength)
{ }
Information::MemoryMapIterator&
Information::MemoryMapIterator::operator++()
{
if (mCount > 0) {
auto p = reinterpret_cast<uint32_t *>(mCurrent);
if (mLength > 0) {
// The size of the current struct is stored at (mCurrent - 4) bytes.
mCurrent = (mCurrent + p[-1]);
mCount--;
auto size = *reinterpret_cast<uint32_t*>(mCurrent) + 4;
mCurrent = mCurrent + size;
mLength = (size > mLength) ? 0 : mLength - size;
}
return *this;
return *this;
}
Information::MemoryMapIterator
Information::MemoryMapIterator::operator++(int)
{
MemoryMapIterator tmp(reinterpret_cast<uint32_t>(mCurrent), mCount);
MemoryMapIterator tmp(mCurrent, mLength);
operator++();
return tmp;
}
@ -90,10 +90,7 @@ Information::MemoryMapIterator::operator++(int)
MemoryChunk
Information::MemoryMapIterator::operator*()
{
if (mCount == 0) {
return MemoryChunk{0, 0, 0};
}
return *mCurrent;
return *reinterpret_cast<MemoryChunk*>(mCurrent+4);
}
@ -101,11 +98,11 @@ bool
Information::MemoryMapIterator::operator==(const MemoryMapIterator& other)
const
{
if (mCount == 0 && other.mCount == 0) {
if (mLength == 0 && other.mLength == 0) {
// If both iterators have 0 counts, it doesn't matter what the mCurrent members point at.
return true;
}
return mCurrent == other.mCurrent && mCount == other.mCount;
return mCurrent == other.mCurrent && mLength == other.mLength;
}
@ -150,17 +147,6 @@ Information::commandLine()
}
uint32_t
Information::memoryMapChunks()
const
{
if ((mFlags & Present::MemoryMap) == 0) {
return 0;
}
return memoryMapCount;
}
Information::MemoryMapIterator
Information::memoryMapBegin()
const
@ -168,7 +154,8 @@ Information::memoryMapBegin()
if ((mFlags & Present::MemoryMap) == 0) {
return memoryMapEnd();
}
return MemoryMapIterator(memoryMapAddress, memoryMapCount);
auto& console = kernel::Console::systemConsole();
return MemoryMapIterator(mMemoryMapAddress, mMemoryMapLength);
}
@ -178,5 +165,5 @@ Information::memoryMapEnd()
{
return {0, 0};
}
} /* namespace multiboot */

78
src/Multiboot.hh
View file

@ -1,5 +1,5 @@
/* Multiboot.hh
* vim: set tw=80:
* vim: set tw=120:
* Eryn Wells <eryn@erynwells.me>
*/
/**
@ -44,8 +44,8 @@ struct PACKED Information
bool operator!=(const MemoryMapIterator& other) const;
private:
MemoryChunk *mCurrent;
uint32_t mCount;
uint32_t mCurrent;
uint32_t mLength;
};
static const Information *information();
@ -56,7 +56,6 @@ struct PACKED Information
const char* commandLine() const;
uint32_t memoryMapChunks() const;
MemoryMapIterator memoryMapBegin() const;
MemoryMapIterator memoryMapEnd() const;
@ -69,10 +68,7 @@ private:
/** Amount of upper (1 MB to ...) memory, in KB. Maximally, this value is the address of the first upper memory hole, minus 1 MB. */
uint32_t mMemUpper;
/**
* Indicates which BIOS disk the boot loader loaded the OS image from.
* Defined only if `bootDevice == true`.
*/
/** Indicates which BIOS disk the boot loader loaded the OS image from. */
struct PACKED {
/** Third level partition number. If unused this is set to 0xFF. */
uint8_t partitionLevel3;
@ -80,33 +76,27 @@ private:
uint8_t partitionLevel2;
/** Top-level partition number. */
uint8_t partitionLevel1;
/**
* BIOS drive number, as returned by the `INT 0x13` low-level disk
* interface.
*/
/** BIOS drive number, as returned by the `INT 0x13` low-level disk interface. */
uint8_t driveNumber;
} bootDevice;
} mBootDevice;
/**
* Pointer to a C-style string containing the command line arguments.
* Defined only if `commandLinePresent == true`.
*/
/** Pointer to a C-style string containing the command line arguments. */
uint32_t mCommandLine;
/**
* Multiboot Modules
* Indicates what boot modules were loaded along with the kernel image.
* Defined only if `modulesPresent == true`.
* @{
*/
struct PACKED {
/** Number of boot modules present. */
uint32_t count;
/** Pointer to start of boot modules array. */
uint32_t address;
} modules;
/** Number of boot modules present. */
uint32_t mModulesCount;
/** Pointer to start of boot modules array. */
uint32_t mModulesAddress;
/** @} */
// TODO: Document these.
union PACKED
{
union PACKED {
struct PACKED {
uint32_t tableSize;
uint32_t stringSize;
@ -117,42 +107,36 @@ private:
uint32_t number;
uint32_t size;
uint32_t address;
uint32_t shndx;
uint32_t shndx; // TODO: Bad name. What is this?
} elf;
} symbols;
/**
* @defgroup Memory Map
* Points to a buffer containing a memory map of the machine provided by the
* BIOS. Defined only if `memoryMapPresent == true`.
* Defines a buffer containing a memory map provided by the BIOS.
* @{
*/
/** Number of memory map entries present. */
uint32_t memoryMapCount;
/** Length of the buffer, in bytes. The spec is somewhat unclear on this field. */
uint32_t mMemoryMapLength;
/** Pointer to start of memory map entry array. */
uint32_t memoryMapAddress;
uint32_t mMemoryMapAddress;
/** @} */
/**
* Points to a buffer containing a list of drive definitions provided by the
* BIOS. Defined only if `drivesPresent == true`.
* @defgroup Drives
* Defines a buffer containing a list of drive definitions provided by the BIOS.
* @{
*/
struct PACKED {
/** Number of memory map entries present. */
uint32_t count;
/** Pointer to start of memory map entry array. */
uint32_t address;
} drives;
/** Number of memory map entries present. */
uint32_t mDrivesLength;
/** Pointer to start of memory map entry array. */
uint32_t mDrivesAddress;
/** @} */
/**
* Pointer to the table containing APM information. Defined only if
* `apmTablePresent == true`.
*/
uint32_t apmTable;
/** Pointer to a table containing APM information. */
uint32_t mAPMTable;
/**
* I dunno some VBE stuff. TODO.
*/
/** I dunno some VBE stuff. TODO. */
struct PACKED {
uint32_t controlInformation;
uint32_t modeInformation;