The bits that can be set are the enable bit (bit 0) plus the bits represented by exp_bar_cfg which is determined by the size of the ROM which is calculated to be a power of 2 and a minimum of 2K.
The Pointer to PCI Data Structure is supposed to be two bytes. It is described in the PCI Firmware Specification Revision 3.0, section 5.1.1. PCI Expansion ROM Header Format.
The pointer is two bytes at 0x18. The pointer is supposed to be a multiple of 4 which means there's always at least two bytes of padding after the pointer. Some BIOS firmware images may use the 2 bytes following the pointer for other purposes (plus additional bytes before the PCI Data Structure) so we cannot assume the bytes will be zero.
Some PCI expansion ROMs may include both BIOS and Open Firmware images.
dingusppc could not read bytes from offset 1,2,3 or words from offset 2.
dingusppc did not read words from offset 1,3 and longs from offset 1,2,3 in the same way as a real Power Mac 8600 or B&W G3.
This commit fixes those issues.
- Added pci_cfg_rev_read. It takes a 32 bit value from offset 0 and returns a value of the specified size using bytes starting from the specified offset. Offsets 4,5, & 6 wrap around to 0,1, & 2 respectively. The result bytes are in flipped order as required by the pci_cfg_read method (so a value of 0x12345678 is returned as 0x78563412)
A real Power Mac 8600 might return a random byte for offset 4, 5, 6 for vci0 but usually not for pci1. A B&W G3 seems to always wrap around correctly. We won't read random bytes, and we won't read a default such as 00 or FF. We'll do the wrap around which makes the most sense because writing 0x12345678 to any offset and reading from the same offset should produce the value that was written.
- Added pci_cfg_rev_write. It takes a 32 bit value from offset 0, and modifies a specified number of bytes starting at a specified offset with the offset wrapping around to 0 if it exceeds 3. The modified bytes take their new values from the flipped bytes passed to pci_cfg_write. When size is 4, the original value is not used since all bytes will be modified.
Basically, those two functions handle all the sizes and all the offsets and replace calls to BYTESWAP_32, read_mem or read_mem_rev, and write_mem or write_mem_rev.
read_mem_rev, as it was used by pcidevice and some other places, could read beyond offset 3 if it were ever passed a reg_offs value that did not have offset as 0. Since the offset was always zero, it would always read the wrong byte or word if they were not at offset 0. Same for read_mem as used by mpc106.
write_mem_rev, as it was used by pcidevice and some other places, could write beyond offset 3 if it were ever passed a reg_offs value that did not have offset as 0. Since the offset was always zero, it would always write the wrong byte or word if they were not at offset 0. Same for write_mem as used by mpc106.
The PCI controllers (bandit, chaos, mpc106) need to encode the offset (0,1,2,3) into the reg_offs parameter passed to pci_cfg_read and pci_cfg_write so they can return or modify the correct bytes of the dword at reg_offs & 3.
The pci_cfg_read and pci_cfg_write methods extract the offset from reg_offs and report unaligned accesses.
pci_cfg_read uses pci_cfg_rev_read to read from the reg using the size and offset to determine which bytes to read.
pci_cfg_write uses pci_cfg_rev_write to write to the reg using the size and offset to determine which bytes to modify.
Other changes:
- for unimplemented config register reads and writes, bandit and ATIRage now includes offset and size (and value in the case of writes) in log warnings.
- for unimplemented config register reads and writes, pcidevice now includes offset in log warnings.
- pci_read and pci_write of mpc106 require an offset parameter since config_addr does not contain the offset (it is always a multiple of 4). The offset is included in the log warninings for non-existent PCI devices.
- ATIRage uses pci_cfg_rev_read and pci_cfg_rev_write which correctly places user_cfg at byte 0x40 instead of 0x43 and writes the correct byte depending on size and offset.
Notes:
- pci_cfg_read calls READ_DWORD_LE_A and pci_cfg_write calls WRITE_DWORD_LE_A. When reading or writing memory that is organized as little endian dwords, such as my_pci_cfg_hdr of mpc106, the function should explicitly state that it's little endian so that the emulator may be ported one day to a CPU architecture that is not little endian.
Writes to config registers of invalid or non-existent PCI devices are logged. They should be logged with most significant byte first.
The values enter the methods in reverse byte order so they need to be byte swapped (except when size is 1) for logging.
The result is that this command in Open Firmware:
`12345678 16800 config-l!`
will log this:
`VCI0 err: write attempt to non-existing VCI device ??:0d.0 @00.l = 12345678`
Usually bit 1 of I/O BARs is 0 since it is reserved, but control has an I/O BAR where this bit is set.
bar_cfg is used to determine the default values of the least significant bits (2 bits for I/O BARs and 4 bits for Memory BARs).
The upper bits of bar_cfg determine which bits can be set and also determines the size of the BAR.
The bits that can be set are the enable bit (bit 0) plus the bits represented by exp_bar_cfg which is determined by the size of the ROM which is calculated to be a power of 2 and a minimum of 2K.
PCI config read fails should return all 1 bits.
All unused registers in an existing PCI device should return 0.
Because that's what my Power Mac 8600 returns when I run my Open Firmware lspci command.
Any bus/device/function that doesn't exist returns FF and won't be listed by lspci.
Any registers that are unused will show as 00 in the lspci output.
Make grackle log bus:device.function @register.size in all cases.
The expansion rom base register indicates the size of the expansion rom by the number of bits that remain zero after code attempts to set them all to 1. For example, a result of fffe0000 means 128K. The 11 least significant bits are ignored in the size calculation, which means the minimum rom size is indicated by fffff800 = 2K.
Handle the case where an expansion rom file might not have a size that is a multiple of 2 or is not greater than 2K.
Bytes between the end of the file and the end of the calculated rom size are set to 0xff.
Don't always return 0 when reading it. The status register contains some bits that Open Firmware uses to set some properties.
A PCI device can set a default status register value to set those bits.
this->status = 0x02B0; // 0000 0 01 0 1 0 1 1 0000 Capabilities List, 66 MHz, Fast Back-to-Back, DevSel Speed: Medium
For invalid or unsupported PCI accesses, do the following:
- log a device's full pci address using pciutils setpci command format bb:dd.f @rr.s (bus:device:function @register+offset.size).
- report as read or write access.
- log value for writes.
- bus, device, function, and register values cannot be determined from Invalid IDSEL values so they will output as ??.
- for invalid IDSEL values, report the entire value of the config_addr.
- for valid IDSEL values, the bus number cannot be determined since IDSEL only specifies device number. It's probably bus 00 but we'll show ?? to indicate an IDSEL type access.
Add missing config type read access logging for chaos.
