Support for global allocator

[piosystems]

Is there any support for global allocator. Concatenating string slices is not feasible without heap allocator.

[piosystems]

I have attempted using the following code to setup default global allocator. Any concrete example on how this could work with bootloader?

use alloc::alloc::*;

/// The global allocator type.
#[derive(Default)]
pub struct Allocator;

unsafe impl GlobalAlloc for Allocator {
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
malloc(layout.size() as u32) as *mut u8
}
unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
free(ptr as *mut c_void);
}
}

/// If there is an out of memory error, just panic.
#[alloc_error_handler]
fn my_allocator_error(_layout: Layout) -> ! {
panic!("out of memory");
}

/// The static global allocator.
#[global_allocator]
static GLOBAL_ALLOCATOR: Allocator = Allocator;

[phil-opp]

The bootloader does no longer exist after transferring control to your kernel. So you have to implement the memory management yourself. This includes page table table allocation and creating your own allocator. See the "Memory Management" section on https://os.phil-opp.com/ for details.

If you don't want to manage memory, you could create an UEFI application directly. See https://github.com/rust-osdev/uefi-rs/tree/main/template for an example. By using the uefi crate you have direct access to the UEFI boot services provided by the firmware. This allows you to allocate pages through the BootServices::allocate_pool function. You can also include the higher-level uefi-services crate, which will automaticall set up a global allocator for you.

Hope this help!

[piosystems]

Thank you for the feedback. I am following your "Memory Management" section on https://os.phil-opp.com/ but the flow seem not to be compatible with bootloader_api 0.11.x. For example, the newer bootinfo has no memory_map member anymore which is expected by memory::BootInfoFrameAllocator. Instead, there is memory_regions which is available for use. Can you post a quick example update of memory allocation that works with bootloader_api 0.11.x?

[piosystems]

Thank you for the feedback. I am following your "Memory Management" section on https://os.phil-opp.com/ but the flow seem not to be compatible with bootloader_api 0.11.x. For example, the newer bootinfo has no memory_map member anymore which is expected by memory::BootInfoFrameAllocator. Instead, there is memory_regions which is available for use. Can you post a quick example update of memory allocation that works with bootloader_api 0.11.x?

I am still stuck with the fact that for bootloader_api 0.11.x, the boot_info: &'static mut bootloader_api::BootInfo passed to my entry_point does not have memory_map, contrary to what is indicated in https://os.phil-opp.com/ which seems to have been written for earlier versions. Attempts to find ways to use the Allocators in https://os.phil-opp.com/ have been unsuccessful. Am I missing something? Can you give an example of the use of FixedSizeBlockAllocator with bootloader_api 0.11.x?

[yavko]

Thank you for the feedback. I am following your "Memory Management" section on os.phil-opp.com but the flow seem not to be compatible with bootloader_api 0.11.x. For example, the newer bootinfo has no memory_map member anymore which is expected by memory::BootInfoFrameAllocator. Instead, there is memory_regions which is available for use. Can you post a quick example update of memory allocation that works with bootloader_api 0.11.x?

I am still stuck with the fact that for bootloader_api 0.11.x, the boot_info: &'static mut bootloader_api::BootInfo passed to my entry_point does not have memory_map, contrary to what is indicated in os.phil-opp.com which seems to have been written for earlier versions. Attempts to find ways to use the Allocators in os.phil-opp.com have been unsuccessful. Am I missing something? Can you give an example of the use of FixedSizeBlockAllocator with bootloader_api 0.11.x?

I'm pretty sure its been replaced with memory_regions

[piosystems]

I'm pretty sure its been replaced with memory_regions

How do you initialize any Allocator of choice with addresses indicated in memory_regions? Any working example?

[yavko]

I'm pretty sure its been replaced with memory_regions

How do you initialize any Allocator of choice with addresses indicated in memory_regions? Any working example?

i think like so, though havent been able to test (with BootInfoFrameAllocator):

initialization

Updated frame allocator

[piosystems]

I'm pretty sure its been replaced with memory_regions

How do you initialize any Allocator of choice with addresses indicated in memory_regions? Any working example?

i think like so, though havent been able to test (with BootInfoFrameAllocator):

initialization

Updated frame allocator

From what I can see in your posted snippets, it is obvious that my codes are not up to date. Can you point me to the updated repository content url?