From 325ec4c8c8f8243767c49928496c38c06f312438 Mon Sep 17 00:00:00 2001 From: David Harris Date: Fri, 3 May 2024 10:58:44 -0700 Subject: [PATCH] Removed obsolete utility --- tests/testgen/virtual_memory_util.py | 292 --------------------------- 1 file changed, 292 deletions(-) delete mode 100644 tests/testgen/virtual_memory_util.py diff --git a/tests/testgen/virtual_memory_util.py b/tests/testgen/virtual_memory_util.py deleted file mode 100644 index 0aafb3a12..000000000 --- a/tests/testgen/virtual_memory_util.py +++ /dev/null @@ -1,292 +0,0 @@ -#!/usr/bin/python3 -################################## -# virtual_memory_util.py -# -# Jessica Torrey 01 March 2021 -# Thomas Fleming 01 March 2021 -# -# Modified kmacsaigoren@hmc.edu 2 June 2021 -# file now reflects actual use to generate assembly code pagetable. -# file now also includes small guide on how it can be used. -# -# Utility for generating the pagetable for any test assembly code where virtual memory is needed. -################################## - -###################################################### -""" HOW TO USE THIS FILE - -This is all assuming you are writing code very similar to the WALLY-VIRTUALMEMORY tests and would like your own virtual memory map. -This guide is also stored in the WALLY-VIRTUALMEMORY.S file as well. - -Begin by copying an existing page directory over to your test and running make (it'll be wrong, but we'll fix it in a second). - Make may hang or give you an error because the reference outputs may be wrong, but all we're trying to do is get an elf file. -Simulate the test code on your favorite riscv processor simulator with a debugger that will show you internal state/register values. - I used OVPsimPlus with the command 'riscvOVPsimPlus.exe --variant --program --gdbconsole' -Run through the simulation until it has written to satp and read the bottom 60 bits of it. - Assuming you're a test with the same setup code, this should be the value of the base ppn. - -Near the top of the python file you're reading right now, edit the value of 'INITIAL_PPN' to be the base PPN you just found in hex. - -Now find the mappings at the very bottom of the python file. -Each of these loops is adding a mapping from each virtual page in the loop to a physical page somewhere in RAM. - -add or remove mappings as you see fit. the first loop maps VPNs of 0x80000 to 0x80014 onto PPNs of 0x80000 to 0x80014 - you can map single pages or ranges of pages. you can also map multiple VPNs onto the same PPN. - Make sure NOT to include the final VPN that causes the page fault in your test or your program will hang on the j loop instruction (unless you change the end condition). - -double check that you're using the right architecture/svmode in the 'arch' variable - -then run this python file and paste its output at the bottom of your assembly code. Be sure not to delete the signature fills. - -email kmacsaigoren@hmc.edu if you have any questions and he might be able to remember the answers. - -*** Currently doesn't work: mapping something with nonzeros in the VPN[3] feild onto any physical aderss. - It'll produce a page table, but writing to those virtual adresses will not correspond to the correctly mapped physical adresses. - - additionally, the expected behaviour doesn't really work when we try to map to a ram afress that starts with something larger than 000000008 - This could be ebcause of the 32 bit adress space for physical memory. - - remember that these things are broken with this program that generates page tables for test code. it does not say whether the test or module - itself works or not. -*/ - -""" -###################################################### - -################################## -# libraries -################################## -from datetime import datetime -from random import randint, seed, getrandbits -from textwrap import dedent - -################################## -# global structures -################################## -PTE_D = 1 << 7 -PTE_A = 1 << 6 -PTE_G = 1 << 5 -PTE_U = 1 << 4 -PTE_X = 1 << 3 -PTE_W = 1 << 2 -PTE_R = 1 << 1 -PTE_V = 1 << 0 - -PTE_PTR_MASK = ~(PTE_W | PTE_R | PTE_X) - -pgdir = [] - -pages = {} - - -testcase_num = 0 -signature_len = 2000 -signature = [0xff for _ in range(signature_len)] - -# Base PPN, comes after 2 pages of test code and 2 pages of filler signature output space. -# depending on your test however, this value may be different. You can use OVPsimPlus or QEMU with your testcode to find it. -INITIAL_PPN = 0x80005 - - -################################## -# classes -################################## -class Architecture: - def __init__(self, xlen, svMode): - if (xlen == 32): - self.PTESIZE = 4 # bytes - self.PTE_BITS = 32 - - self.VPN_BITS = 20 - self.VPN_SEGMENT_BITS = 10 - - self.PPN_BITS = 22 - - self.LEVELS = 2 - elif (xlen == 64): - if (svMode == 39): - self.PTESIZE = 8 - self.PTE_BITS = 54 - - self.VPN_BITS = 27 - self.VPN_SEGMENT_BITS = 9 - - self.PPN_BITS = 44 - - self.LEVELS = 3 - elif (svMode == 48): - self.PTESIZE = 8 - self.PTE_BITS = 54 - - self.VPN_BITS = 36 - self.VPN_SEGMENT_BITS = 9 - - self.PPN_BITS = 44 - - self.LEVELS = 4 - else: - raise ValueError('Only Sv39 and Sv48 are implemented') - else: - raise ValueError('Only rv32 and rv64 are allowed.') - - self.PGSIZE = 2**12 - self.NPTENTRIES = self.PGSIZE // self.PTESIZE - self.OFFSET_BITS = 12 - self.FLAG_BITS = 8 - self.VA_BITS = self.VPN_BITS + self.OFFSET_BITS - -class PageTableEntry: - def __init__(self, ppn, flags, arch): - assert 0 <= ppn and ppn < 2**arch.PPN_BITS, "Invalid physical page number for PTE" - assert 0 <= flags and flags < 2**arch.FLAG_BITS, "Invalid flags for PTE" - self.ppn = ppn - self.flags = flags - self.arch = arch - - def entry(self): - return (self.ppn << (self.arch.PTE_BITS - self.arch.PPN_BITS)) | self.flags - - def __str__(self): - return "0x{0:0{1}x}".format(self.entry(), self.arch.PTESIZE*2) - - def __repr__(self): - return f"" - -class PageTable: - """ - Represents a single level of the page table, located at some physical page - number `ppn` with symbol `name`, using a specified architecture `arch`. - """ - def __init__(self, name, ppn, arch): - self.table = {} - self.name = name - self.ppn = ppn - self.arch = arch - - self.children = 0 - - pages[ppn] = self - - def add_entry(self, vpn_segment, ppn, flags): - if not (0 <= vpn_segment < 2**self.arch.VPN_SEGMENT_BITS): - raise ValueError("Invalid virtual page segment number") - self.table[vpn_segment] = PageTableEntry(ppn, flags, self.arch) - - def add_mapping(self, va, pa, flags): - """ - Maps a virtual address `va` to a physical address `pa` with given `flags`, - creating missing page table levels as needed. - """ - if not (0 <= va < 2**self.arch.VA_BITS): - raise ValueError("Invalid virtual page number") - - vpn = virtual_to_vpn(va, self.arch) - ppn = pa >> self.arch.OFFSET_BITS - current_level = self - - pathname = self.name - - for level in range(self.arch.LEVELS - 1, -1, -1): - if level == 0: - current_level.add_entry(vpn[level], ppn, flags) - elif vpn[level] in current_level.table: - current_level = pages[current_level.table[vpn[level]].ppn] - pathname += f"_{current_level.name}" - else: - next_level_ppn = next_ppn() - current_level.add_entry(vpn[level], next_level_ppn, flags & PTE_PTR_MASK) - pathname += f"_t{current_level.children}" - current_level.children += 1 - pages[next_level_ppn] = PageTable(pathname, next_level_ppn, self.arch) - current_level = pages[next_level_ppn] - - def assembly(self): - # Sort the page table - entries = list(sorted(self.table.items(), key=lambda item: item[0])) - current_index = 0 - - # Align the table - asm = f".balign {self.arch.PGSIZE}\n{self.name}:\n" - for entry in entries: - vpn_index, pte = entry - if current_index < vpn_index: - asm += f" .fill {vpn_index - current_index}, {self.arch.PTESIZE}, 0\n" - asm += f" .{self.arch.PTESIZE}byte {str(pte)}\n" - current_index = vpn_index + 1 - if current_index < self.arch.NPTENTRIES: - asm += f" .fill {self.arch.NPTENTRIES - current_index}, {self.arch.PTESIZE}, 0\n" - return asm - - def __str__(self): - return self.assembly() - - def __repr__(self): - return f"" - - -################################## -# functions -################################## - -def virtual_to_vpn(vaddr, arch): - if not (0 <= vaddr < 2**arch.VA_BITS): - raise ValueError("Invalid physical address") - - page_number = [0 for _ in range(arch.LEVELS)] - - vaddr = vaddr >> arch.OFFSET_BITS - mask = 2**arch.VPN_SEGMENT_BITS - 1 - for level in range(arch.LEVELS): - page_number[level] = vaddr & mask - vaddr = vaddr >> arch.VPN_SEGMENT_BITS - - return page_number - -next_free_ppn = INITIAL_PPN -def next_ppn(): - global next_free_ppn - ppn = next_free_ppn - next_free_ppn += 1 - return ppn - -def print_pages(): - for page in pages: - print(pages[page]) - -################################## -# helper variables -################################## -sv32 = Architecture(32, 32) -sv39 = Architecture(64, 39) -sv48 = Architecture(64, 48) - -if __name__ == "__main__": - arch = sv39 - pgdir = PageTable("page_directory", next_ppn(), arch) - - # Directly map the first 20 pages of RAM - for page in range(20): - vaddr = 0x80000000 + (arch.PGSIZE * page) - paddr = 0x80000000 + (arch.PGSIZE * page) - pgdir.add_mapping(vaddr, paddr, PTE_D | PTE_A | PTE_R | PTE_W | PTE_U | PTE_X | PTE_V) - - # Map Vpn of of the offset below and the 20 pages after it mapped onto the same 20 pages of ram. - # the first two of these are also the location of the output for each test. - for page in range(40): - vaddr = 0x00000000 + (arch.PGSIZE * page) - paddr = 0x80000000 + (arch.PGSIZE * page) - if page >= 20: - pgdir.add_mapping(vaddr, paddr, PTE_D | PTE_A | PTE_R | PTE_W | PTE_U | PTE_X | 0) # gives me an invalid mapping where I can try to store/read to force a page fault. - else: - pgdir.add_mapping(vaddr, paddr, PTE_D | PTE_A | PTE_R | PTE_W | PTE_U | PTE_X | PTE_V) - - - """ - supervisor_pgdir = PageTable("sdir", next_ppn(), rv64) - supervisor_pgdir.add_mapping(0x80000000, 0x80000000, PTE_R | PTE_W | PTE_X) - supervisor_pgdir.add_mapping(0x80000001, 0x80000001, PTE_R | PTE_W | PTE_X) - supervisor_pgdir.add_mapping(0x80001000, 0x80000000, PTE_R | PTE_W | PTE_X) - supervisor_pgdir.add_mapping(0xffff0000, 0x80000000, PTE_R | PTE_W | PTE_X) - """ - - print_pages()