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| author | H. Peter Anvin <hpa@zytor.com> | 2014-01-16 10:54:02 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2014-01-16 10:56:29 -0800 |
| commit | 1d01a26f07910da394a733421f1308830d490e94 (patch) | |
| tree | 243fefe7d518fd4217879f419134c7aa9cc5d86e | |
| parent | 9ab3608ba4a51e234f251d84f764f39f20e4ded3 (diff) | |
| download | syslinux-1d01a26f07910da394a733421f1308830d490e94.tar.gz syslinux-1d01a26f07910da394a733421f1308830d490e94.tar.xz syslinux-1d01a26f07910da394a733421f1308830d490e94.zip | |
dos: We cannot use memset() for a far object, introduce memset_sl()
We started using memset() on the extents buffer in ldlinux.sys, which
doesn't reside in the main segment, which worked on all the installer
platforms except DOS. Fix DOS by introducing memset_sl() for this
case.
Reported-by: Ady <ady-sf@hotmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| -rw-r--r-- | dos/getsetsl.c | 17 | ||||
| -rw-r--r-- | libinstaller/syslxint.h | 2 | ||||
| -rw-r--r-- | libinstaller/syslxmod.c | 2 |
3 files changed, 20 insertions, 1 deletions
diff --git a/dos/getsetsl.c b/dos/getsetsl.c index fadef438..5260a2a1 100644 --- a/dos/getsetsl.c +++ b/dos/getsetsl.c @@ -123,3 +123,20 @@ void memcpy_from_sl(void *dst, const void *src, size_t len) : "r" (seg) : "memory"); } + +void memset_sl(void *dst, int c, size_t len) +{ + uint16_t seg; + uint16_t off; + + seg = ds() + ((size_t)dst >> 4); + off = (size_t)dst & 15; + + asm volatile("pushw %%es ; " + "movw %3,%%es ; " + "rep ; stosb ; " + "popw %%es" + : "+D" (off), "+c" (len) + : "a" (c), "r" (seg) + : "memory"); +} diff --git a/libinstaller/syslxint.h b/libinstaller/syslxint.h index 59e3e5ef..ce9cb209 100644 --- a/libinstaller/syslxint.h +++ b/libinstaller/syslxint.h @@ -134,6 +134,7 @@ void set_32_sl(uint32_t * p, uint32_t v); void set_64_sl(uint64_t * p, uint64_t v); void memcpy_to_sl(void *dst, const void *src, size_t len); void memcpy_from_sl(void *dst, const void *src, size_t len); +void memset_sl(void *dst, int c, size_t len); #else @@ -148,6 +149,7 @@ void memcpy_from_sl(void *dst, const void *src, size_t len); #define set_64_sl(x,y) set_64(x,y) #define memcpy_to_sl(d,s,l) memcpy(d,s,l) #define memcpy_from_sl(d,s,l) memcpy(d,s,l) +#define memset_sl(d,c,l) memset(d,c,l) #endif diff --git a/libinstaller/syslxmod.c b/libinstaller/syslxmod.c index 98e2710a..197261ca 100644 --- a/libinstaller/syslxmod.c +++ b/libinstaller/syslxmod.c @@ -41,7 +41,7 @@ static void generate_extents(struct syslinux_extent *ex, int nptrs, base = addr; len = lba = 0; - memset(ex, 0, nptrs * sizeof *ex); + memset_sl(ex, 0, nptrs * sizeof *ex); while (nsect) { sect = *sectp++; |