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kernel/ATA: Add support for regular ATA drives (non-ATAPI)

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Don't know why this took so long to figure out, I just had to pass the right value to select().
This commit is contained in:
apio 2024-03-29 12:11:39 +01:00
parent 86372a3893
commit 6443ec77f8
Signed by: apio
GPG Key ID: B8A7D06E42258954
2 changed files with 108 additions and 24 deletions
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123
kernel/src/arch/x86_64/disk/ATA.cpp
View File

@ -157,13 +157,27 @@ namespace ATA
void Channel::select(u8 drive)
{
if (drive == m_current_drive) return;
u8 value = (u8)(drive << 4) | 0xa0;
if (value == m_current_select_value) return;
write_register(Register::DriveSelect, value);
delay_400ns();
m_current_select_value = value;
m_current_drive = drive;
}
void Channel::select(u8 base, u8 drive)
{
u8 value = (u8)(drive << 4) | base;
if (value == m_current_select_value) return;
write_register(Register::DriveSelect, value);
delay_400ns();
m_current_select_value = value;
m_current_drive = drive;
}
@ -543,10 +557,61 @@ namespace ATA
return true;
}
Result<void> Drive::send_packet_atapi_pio(const atapi_packet* packet, void* out, u16 response_size)
void Drive::select_lba(u64 lba, usize count)
{
if (m_is_lba48)
{
m_channel->write_register(Register::SectorCount, (u8)((count >> 8) & 0xff));
m_channel->write_register(Register::LBALow, (u8)((lba >> 24) & 0xff));
m_channel->write_register(Register::LBAMiddle, (u8)((lba >> 32) & 0xff));
m_channel->write_register(Register::LBAHigh, (u8)((lba >> 40) & 0xff));
}
m_channel->write_register(Register::SectorCount, (u8)(count & 0xff));
m_channel->write_register(Register::LBALow, (u8)(lba & 0xff));
m_channel->write_register(Register::LBAMiddle, (u8)((lba >> 8) & 0xff));
m_channel->write_register(Register::LBAHigh, (u8)((lba >> 16) & 0xff));
}
Result<void> Drive::read_pio_bytes(void* out, usize size)
{
u8* ptr = (u8*)out;
usize i = 0;
while (i < size)
{
TRY(m_channel->wait_until_ready());
usize byte_count;
if (m_is_atapi)
{
byte_count =
m_channel->read_register(Register::LBAHigh) << 8 | m_channel->read_register(Register::LBAMiddle);
}
else
byte_count = min(512ul, size - i);
usize word_count = byte_count / 2;
while (word_count--)
{
u16 value = m_channel->read_data();
ptr[0] = (u8)(value & 0xff);
ptr[1] = (u8)(value >> 8);
ptr += 2;
}
i += byte_count;
m_channel->delay_400ns();
}
return {};
}
Result<void> Drive::send_packet_atapi_pio(const atapi_packet* packet, void* out, u16 response_size)
{
m_channel->select(m_drive_index);
// We use PIO here.
@ -559,30 +624,11 @@ namespace ATA
m_channel->delay_400ns();
usize i = 0;
TRY(m_channel->wait_until_ready());
for (int j = 0; j < 6; j++) m_channel->write_data(packet->command_words[j]);
while (i < response_size)
{
TRY(m_channel->wait_until_ready());
usize byte_count =
m_channel->read_register(Register::LBAHigh) << 8 | m_channel->read_register(Register::LBAMiddle);
usize word_count = byte_count / 2;
while (word_count--)
{
u16 value = m_channel->read_data();
ptr[0] = (u8)(value & 0xff);
ptr[1] = (u8)(value >> 8);
ptr += 2;
}
i += byte_count;
}
TRY(read_pio_bytes(out, response_size));
return {};
}
@ -704,6 +750,26 @@ namespace ATA
return send_packet_atapi_pio(&read_packet, out, (u16)size);
}
Result<void> Drive::ata_read_pio(u64 lba, void* out, usize size)
{
check(lba < m_block_count);
check(size <= ARCH_PAGE_SIZE);
usize count = ceil_div(size, m_block_size);
m_channel->select(m_is_lba48 ? 0x40 : (0xe0 | ((lba >> 24) & 0xf)), m_drive_index);
select_lba(lba, count);
m_channel->write_register(Register::Command, m_is_lba48 ? CMD_ReadSectorsExt : CMD_ReadSectors);
m_channel->delay_400ns();
TRY(read_pio_bytes(out, size));
return {};
}
Result<void> Drive::read_lba(u64 lba, void* out, usize nblocks)
{
const usize blocks_per_page = ARCH_PAGE_SIZE / m_block_size;
@ -719,7 +785,16 @@ namespace ATA
return atapi_read_pio(lba, out, nblocks * m_block_size);
}
else
todo();
{
while (nblocks > blocks_per_page)
{
TRY(ata_read_pio(lba, out, ARCH_PAGE_SIZE));
lba += blocks_per_page;
nblocks -= blocks_per_page;
out = offset_ptr(out, ARCH_PAGE_SIZE);
}
return ata_read_pio(lba, out, nblocks * m_block_size);
}
}
void Drive::irq_handler()

9
kernel/src/arch/x86_64/disk/ATA.h
View File

@ -54,6 +54,8 @@ namespace ATA
enum CommandRegister : u8
{
CMD_ReadSectors = 0x20,
CMD_ReadSectorsExt = 0x24,
CMD_Identify = 0xec,
CMD_Packet = 0xa0,
CMD_Identify_Packet = 0xa1
@ -180,6 +182,11 @@ namespace ATA
Result<void> atapi_read_pio(u64 lba, void* out, usize size);
Result<void> ata_read_pio(u64 lba, void* out, usize size);
void select_lba(u64 lba, usize count);
Result<void> read_pio_bytes(void* out, usize size);
Channel* m_channel;
u8 m_drive_index;
@ -250,6 +257,7 @@ namespace ATA
}
void select(u8 drive);
void select(u8 base, u8 drive);
bool initialize();
@ -270,6 +278,7 @@ namespace ATA
bool m_irq_called { false };
u8 m_current_drive = (u8)-1;
u8 m_current_select_value = 0xff;
Option<Drive> m_drives[2];
};