vasilito
e8ec916158
The FADT_MIN_SIZE_ACPI_2_0 and FADT_MIN_SIZE_ACPI_1_0 constants were defined as usize, but the Sdt::length() method they are compared against returns u32. On x86_64, this is a type mismatch because usize is u64 and u32 is u32 — the comparison sdt.length() >= FADT_MIN_SIZE_ACPI_2_0 fails to compile with E0308 'expected u32, found usize' (the inferred LHS type is u32, the RHS constant is usize). Root cause: the constants were originally written for a build target where usize == u32 (i386), so the implicit comparison worked. When the target moved to x86_64, the type mismatch became visible but was never resolved. Fix: change both constants to u32. The values 148 and 76 are trivially representable in u32 (ACPI spec FADT minimum size limits), and u32 matches the Sdt::length() return type per the ACPI 6.5 spec which defines the SDT length field as a 32-bit integer. This was the lone remaining cargo check error in the local kernel fork, blocking clean cargo check validation of every other change. With this fix, cargo check now exits 0 (modulo pre-existing unrelated warnings). The fadt.rs module was touched in earlier Red Bear OS commits (9bc1fbf'fix Phase II.X.W FACS parser + Sdt length() + UserSlice access' and475f96e'comprehensive FACS parser') but the type mismatch on the constant was not fixed at that time.
Kernel
Redox OS Microkernel
Requirements
nasmneeds to be available on the PATH at build time.
Building The Documentation
Use this command:
cargo doc --open --target x86_64-unknown-none
Debugging
QEMU
Running QEMU with the -s flag will set up QEMU to listen on port 1234 for a GDB client to connect to it. To debug the redox kernel run.
make qemu gdb=yes
This will start a virtual machine with and listen on port 1234 for a GDB or LLDB client.
GDB
If you are going to use GDB, run these commands to load debug symbols and connect to your running kernel:
(gdb) symbol-file build/kernel.sym
(gdb) target remote localhost:1234
LLDB
If you are going to use LLDB, run these commands to start debugging:
(lldb) target create -s build/kernel.sym build/kernel
(lldb) gdb-remote localhost:1234
After connecting to your kernel you can set some interesting breakpoints and continue
the process. See your debuggers man page for more information on useful commands to run.
Notes
-
Always use
foo.get(n)instead offoo[n]and try to cover for the possibility ofOption::None. Doing the regular way may work fine for applications, but never in the kernel. No possible panics should ever exist in kernel space, because then the whole OS would just stop working. -
If you receive a kernel panic in QEMU, use
pkill qemu-systemto kill the frozen QEMU process.
How To Contribute
To learn how to contribute to this system component you need to read the following document:
Development
To learn how to do development with this system component inside the Redox build system you need to read the Build System and Coding and Building pages.
How To Build
To build this system component you need to download the Redox build system, you can learn how to do it on the Building Redox page.
This is necessary because they only work with cross-compilation to a Redox virtual machine, but you can do some testing from Linux.
Funding - Unix-style Signals and Process Management
This project is funded through NGI Zero Core, a fund established by NLnet with financial support from the European Commission's Next Generation Internet program. Learn more at the NLnet project page.
