From 0243b256d6187ea610174531607366945e489605 Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Tue, 12 Feb 2008 14:35:39 +0000 Subject: Add stubdomain support. See stubdom/README for usage details. - Move PAGE_SIZE and STACK_SIZE into __PAGE_SIZE and __STACK_SIZE in arch_limits.h so as to permit getting them from there without pulling all the internal Mini-OS defines. - Setup a xen-elf cross-compilation environment in stubdom/cross-root - Add a POSIX layer on top of Mini-OS by linking against the newlib C library and lwIP, and implementing the Unixish part in mini-os/lib/sys.c - Cross-compile zlib and libpci too. - Add an xs.h-compatible layer on top of Mini-OS' xenbus. - Cross-compile libxc with an additional xc_minios.c and a few things disabled. - Cross-compile ioemu with an additional block-vbd, but without sound, tpm and other details. A few hacks are needed: - Align ide and scsi buffers at least on sector size to permit direct transmission to the block backend. While we are at it, just page-align it to possibly save a segment. Also, limit the scsi buffer size because of limitations of the block paravirtualization protocol. - Allocate big tables dynamically rather that letting them go to bss: when Mini-OS gets installed in memory, bss is not lazily allocated, and doing so during Mini-OS is unnecessarily trick while we can simply use malloc. - Had to change the Mini-OS compilation somehow, so as to export Mini-OS compilation flags to the Makefiles of libxc and ioemu. Signed-off-by: Samuel Thibault --- extras/mini-os/mm.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'extras/mini-os/mm.c') diff --git a/extras/mini-os/mm.c b/extras/mini-os/mm.c index 11e249d421..f204fa66ec 100644 --- a/extras/mini-os/mm.c +++ b/extras/mini-os/mm.c @@ -360,6 +360,29 @@ void free_pages(void *pointer, int order) } +#ifdef HAVE_LIBC +void *sbrk(ptrdiff_t increment) +{ + unsigned long old_brk = brk; + unsigned long new_brk = old_brk + increment; + + if (new_brk > heap_end) { + printk("Heap exhausted: %p + %lx = %p > %p\n", old_brk, increment, new_brk, heap_end); + return NULL; + } + + if (new_brk > heap_mapped) { + unsigned long n = (new_brk - heap_mapped + PAGE_SIZE - 1) / PAGE_SIZE; + do_map_zero(heap_mapped, n); + heap_mapped += n * PAGE_SIZE; + } + + brk = new_brk; + + return (void *) old_brk; +} +#endif + void init_mm(void) -- cgit v1.2.3