Mercurial > sdl-ios-xcode
changeset 1798:49b4b8413734
Date: Tue, 9 May 2006 23:01:49 -0400
From: Mike Frysinger
Subject: [SDL] [patch] fall back to using MAP_PRIVATE with mmap() in fbcon dri
trying to use MAP_SHARED with mmap() on uClinux (aka non-mmu) hosts nowadays
will simply fail since the kernel disallows it ... falling back to using
MAP_PRIVATE on these hosts is acceptable ... as such, ive attached a patch
for the fbcon driver that will fall back to using MAP_PRIVATE if mmap() with
MAP_SHARED failed
going by a grep of MAP_SHARED, the only other drivers that utilize this flag
are video/wscons, video/ps2gs, and sound/dmaaudio ... i dont think these
would appear on a non-mmu host so the patch i wrote is restricted to just
SDL_fbvideo.c ...
-mike
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Wed, 10 May 2006 04:05:46 +0000 |
| parents | 783b9409baa0 |
| children | 50e9cca3fe7b |
| files | src/video/fbcon/SDL_fbvideo.c |
| diffstat | 1 files changed, 15 insertions(+), 2 deletions(-) [+] |
line wrap: on
line diff
--- a/src/video/fbcon/SDL_fbvideo.c Tue May 09 16:10:04 2006 +0000 +++ b/src/video/fbcon/SDL_fbvideo.c Wed May 10 04:05:46 2006 +0000 @@ -149,6 +149,19 @@ struct fb_var_screeninfo *vinfo); static void FB_RestorePalette(_THIS); +/* Small wrapper for mmap() so we can play nicely with no-mmu hosts + * (non-mmu hosts disallow the MAP_SHARED flag) */ + +static void *do_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset) +{ + void *ret; + ret = mmap(start, length, prot, flags, fd, offset); + if ( ret == (char *)-1 && (flags & MAP_SHARED) ) { + ret = mmap(start, length, prot, + (flags & ~MAP_SHARED) | MAP_PRIVATE, fd, offset); + } +} + /* FB driver bootstrap functions */ static int FB_Available(void) @@ -535,7 +548,7 @@ mapped_offset = (((long)finfo.smem_start) - (((long)finfo.smem_start)&~(PAGE_SIZE-1))); mapped_memlen = finfo.smem_len+mapped_offset; - mapped_mem = mmap(NULL, mapped_memlen, + mapped_mem = do_mmap(NULL, mapped_memlen, PROT_READ|PROT_WRITE, MAP_SHARED, console_fd, 0); if ( mapped_mem == (char *)-1 ) { SDL_SetError("Unable to memory map the video hardware"); @@ -579,7 +592,7 @@ ioctl(console_fd, FBIOPUT_VSCREENINFO, &vinfo); if ( finfo.accel && finfo.mmio_len ) { mapped_iolen = finfo.mmio_len; - mapped_io = mmap(NULL, mapped_iolen, PROT_READ|PROT_WRITE, + mapped_io = do_mmap(NULL, mapped_iolen, PROT_READ|PROT_WRITE, MAP_SHARED, console_fd, mapped_memlen); if ( mapped_io == (char *)-1 ) { /* Hmm, failed to memory map I/O registers */