Function platform_alloc

loader/efi/src/platform.c:95–117

* <!-- description --> * @brief This function allocates read/write virtual memory from the * kernel. This memory is not physically contiguous. The resulting * pointer is at least 4k aligned, so use this function sparingly * as it will always allocate at least one page. Use platform_free() * to release this memory. * * @note This function must zero the allocated memory *

 *     Returns a nullptr on failure.
 */
NODISCARD void *
platform_alloc(uint64_t size)
{
    EFI_STATUS status = EFI_SUCCESS;
    EFI_PHYSICAL_ADDRESS ret = ((EFI_PHYSICAL_ADDRESS)0);

    platform_expects(((uint64_t)0) != size);

    if (((uint64_t)0) != (size & (HYPERVISOR_PAGE_SIZE - ((uint64_t)1)))) {
        size += HYPERVISOR_PAGE_SIZE;
        size &= ~(HYPERVISOR_PAGE_SIZE - ((uint64_t)1));
    }

    status = g_st->BootServices->AllocatePages(
        AllocateAnyPages, EfiRuntimeServicesData, size / HYPERVISOR_PAGE_SIZE, &ret);
    if (EFI_ERROR(status)) {
        bferror_x64("AllocatePages failed", status);
        return NULL;
    }

    g_st->BootServices->SetMem((void *)ret, size, ((UINT8)0));
    return (void *)ret;
}

/**
 * <!-- description -->