diff options
Diffstat (limited to 'i386')
| -rw-r--r-- | i386/i386at/model_dep.c | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/i386/i386at/model_dep.c b/i386/i386at/model_dep.c index 1f7596c..b3fca62 100644 --- a/i386/i386at/model_dep.c +++ b/i386/i386at/model_dep.c @@ -85,13 +85,13 @@ static vm_size_t avail_remaining; if zero, only use physical memory in the low 16MB of addresses. Only SCSI still has DMA problems. */ #ifdef LINUX_DEV -int use_all_mem = 1; +#define use_all_mem 1 #else #include "nscsi.h" #if NSCSI > 0 -int use_all_mem = 0; +#define use_all_mem 0 #else -int use_all_mem = 1; +#define use_all_mem 1 #endif #endif @@ -444,12 +444,13 @@ unsigned int pmap_free_pages() } /* Always returns page-aligned regions. */ -boolean_t +static boolean_t init_alloc_aligned(vm_size_t size, vm_offset_t *addrp) { vm_offset_t addr; extern char start[], end[]; int i; + static int wrapped = 0; /* Memory regions to skip. */ vm_offset_t cmdline_start_pa = boot_info.flags & MULTIBOOT_CMDLINE @@ -469,8 +470,25 @@ init_alloc_aligned(vm_size_t size, vm_offset_t *addrp) /* Page-align the start address. */ avail_next = round_page(avail_next); + /* Start with memory above 16MB, reserving the low memory for later. */ + if (use_all_mem && !wrapped && phys_last_addr > 16 * 1024*1024) + { + if (avail_next < 16 * 1024*1024) + avail_next = 16 * 1024*1024; + else if (avail_next == phys_last_addr) + { + /* We have used all the memory above 16MB, so now start on + the low memory. This will wind up at the end of the list + of free pages, so it should not have been allocated to any + other use in early initialization before the Linux driver + glue initialization needs to allocate low memory. */ + avail_next = 0x1000; + wrapped = 1; + } + } + /* Check if we have reached the end of memory. */ - if (avail_next == phys_last_addr) + if (avail_next == (wrapped ? 16 * 1024*1024 : phys_last_addr)) return FALSE; /* Tentatively assign the current location to the caller. */ |