diff options
| -rw-r--r-- | subx/010---vm.cc | 7 | ||||
| -rw-r--r-- | subx/011run.cc | 2 |
2 files changed, 7 insertions, 2 deletions
diff --git a/subx/010---vm.cc b/subx/010---vm.cc index c862ed99..388fb12b 100644 --- a/subx/010---vm.cc +++ b/subx/010---vm.cc @@ -94,8 +94,8 @@ const uint32_t INITIAL_SEGMENT_SIZE = 0x1000 - 1; // Subtract one just so we can start the first segment at address 1 without // overflowing the first segment. Other segments will learn to adjust. -// Like in real-world Linux, we'll allocate RAM for our programs in slabs -// called VMAs or Virtual Memory Areas. +// Like in real-world Linux, we'll allocate RAM for our programs in disjoint +// slabs called VMAs or Virtual Memory Areas. struct vma { uint32_t start; // inclusive uint32_t end; // exclusive @@ -126,6 +126,9 @@ struct vma { :(before "End Globals") // RAM is made of VMAs. +// +// We currently have zero tests for overlapping VMAs. Particularly after +// growing segments. vector<vma> Mem; :(code) // The first 3 VMAs are special. When loading ELF binaries in later layers, diff --git a/subx/011run.cc b/subx/011run.cc index 22eaad9d..b3fc7684 100644 --- a/subx/011run.cc +++ b/subx/011run.cc @@ -224,6 +224,8 @@ void load(const program& p) { for (int i = 0; i < SIZE(p.segments); ++i) { const segment& seg = p.segments.at(i); uint32_t addr = seg.start; + // you should probably keep your segments disjoint + // but tests sometimes don't if (!already_allocated(addr)) Mem.push_back(vma(seg.start)); trace(99, "load") << "loading segment " << i << " from " << HEXWORD << addr << end(); |