diff options
Diffstat (limited to 'libc/malloc2')
| -rw-r--r-- | libc/malloc2/Config | 1 | ||||
| -rw-r--r-- | libc/malloc2/Makefile | 23 | ||||
| -rw-r--r-- | libc/malloc2/README | 19 | ||||
| -rw-r--r-- | libc/malloc2/malloc.c | 127 | ||||
| -rw-r--r-- | libc/malloc2/malloc.h | 21 | ||||
| -rw-r--r-- | libc/malloc2/stack.c | 10 |
6 files changed, 201 insertions, 0 deletions
diff --git a/libc/malloc2/Config b/libc/malloc2/Config new file mode 100644 index 0000000..11c476d --- /dev/null +++ b/libc/malloc2/Config @@ -0,0 +1 @@ +malloc: Joel's malloc functions diff --git a/libc/malloc2/Makefile b/libc/malloc2/Makefile new file mode 100644 index 0000000..0396df2 --- /dev/null +++ b/libc/malloc2/Makefile @@ -0,0 +1,23 @@ + +TOP=.. +include $(TOP)/Make.defs + +MOBJ=malloc.o stack.o + +OBJ=$(MOBJ) + +all: $(OBJ) + +libc.a: $(OBJ) + ar r ../$(LIBC) $(OBJ) + @touch libc.a + +clean: + rm -f $(OBJ) libc.a + +$(AOBJ): $(ASRC) + $(CC) $(CFLAGS) -c -DL_$* -o $@ $(ASRC) + +transfer: + -@rm ../include/malloc.h + cp -p malloc.h ../include/. diff --git a/libc/malloc2/README b/libc/malloc2/README new file mode 100644 index 0000000..ecf3fd2 --- /dev/null +++ b/libc/malloc2/README @@ -0,0 +1,19 @@ +This is just the malloc for libc. It is untested; it won't even compile +right now. In particular, __malloc_init needs some bug fixing! + +Apparently, there is another malloc that Robert Debath wrote which probably +works by now. However, I honestly think that my malloc may be just as +good when it's finished. + +In about six months, you'll probably see something like this: + + +Linux/less-than-32-bit installation program +Do you want + 1. Chad Page's kernel + 2. Alan Cox's kernel +Enter your chioce --> 2 +Do you want + 1. Robert Debath's malloc + 2. Joel Weber's malloc +[more choices for compilers, filetools, etc] diff --git a/libc/malloc2/malloc.c b/libc/malloc2/malloc.c new file mode 100644 index 0000000..143d324 --- /dev/null +++ b/libc/malloc2/malloc.c @@ -0,0 +1,127 @@ +/* simplified linux malloc.h + Copyright (C) 1995 Joel N. Weber II + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <malloc.h> + +typedef struct __malloc_struct malloc_struct; + +typedef union __malloc_union +{ + char *c; + malloc_struct *m; +} malloc_union; + + +struct __malloc_struct +{ + unsigned char status; +#define ALLOC 0x53 +#define FREE 0x55 +#define END_OF_WORLD 0x57 + malloc_union next; +} *malloc_start; + +extern int __STACKSIZE; + +/* WARNING: this init will only work if there is a hard limit on the + amount of RAM that can be allocated. + */ + +#ifdef __AS386_16__ +#asm + loc 1 ! Make sure the pointer is in the correct segment +auto_func: ! Label for bcc -M to work. + .word _malloc_init ! Pointer to the autorun function + .word no_op ! Space filler cause segs are padded to 4 bytes. + .text ! So the function after is also in the correct seg. +#endasm +#endif + +malloc_init() +{ + extern unsigned int sbrk(); + + unsigned int ptr, sz, count; + + malloc_start = (malloc_struct*) ((sbrk(16)+1)&~1); + malloc_start->status = FREE; + + count=254; + for(sz=16384; sz>64; ) + { + ptr= sbrk(sz); + if( ptr == (unsigned)-1 ) sz>>=1; + else count+=sz; + } + if( __STACKSIZE > count || __STACKSIZE <= 0 ) __STACKSIZE = ((count>>1)&-2); + ptr = sbrk(-__STACKSIZE); + + malloc_start->next.m = ((malloc_struct*)ptr) - 1; + + malloc_start->next.m->status = END_OF_WORLD; +} + +char *malloc(size) +size_t size; +{ + register malloc_union tmp, tmp2; + + /* Make sure we don't lose the alignment */ + size = (size+sizeof(malloc_struct)-1)/sizeof(malloc_struct); + + tmp.m = malloc_start; + while ( ( tmp.m->next.m - tmp.m - 2 ) < size + || ( tmp.m->status == ALLOC )) + tmp.m = tmp.m->next.m; + + if (tmp.m->status == FREE){ + tmp2.m = size + tmp.m + 1; + tmp2.m->status = FREE; + tmp2.m->next.c = tmp.m->next.c; + tmp.m->status = ALLOC; + tmp.m->next.c = tmp2.c; + } + else return 0; + tmp.m++; + return tmp.c; +} + +__malloc_cleanup() /* finds consecutive free blocks and joins them */ +{ + malloc_struct *tmp; + + tmp = malloc_start; + while ((tmp->status != END_OF_WORLD)&&(tmp->next.m->status != END_OF_WORLD)){ + if ((tmp->status==FREE)&&(tmp->next.m->status==FREE)) + tmp->next.m = tmp->next.m->next.m; + else tmp = tmp->next.m; + } +} + +free(what) +char *what; +{ + malloc_union tmp; + + tmp.c = what; tmp.m--; + if( tmp.m->status == ALLOC ) + { + tmp.m->status = FREE; + __malloc_cleanup; + } +} diff --git a/libc/malloc2/malloc.h b/libc/malloc2/malloc.h new file mode 100644 index 0000000..ffcb3a4 --- /dev/null +++ b/libc/malloc2/malloc.h @@ -0,0 +1,21 @@ +/* simplified linux malloc.h + Copyright (C) 1995 Joel N. Weber II + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +char *malloc(size); +void free(what); +char *realloc(what, size); diff --git a/libc/malloc2/stack.c b/libc/malloc2/stack.c new file mode 100644 index 0000000..5f33e21 --- /dev/null +++ b/libc/malloc2/stack.c @@ -0,0 +1,10 @@ + +/* + * Under Linux 8086 the stack and heap areas are at the top and bottom + * of the same area of memory, this version of malloc requires that the + * malloc area is of a fixed size this means that there must also be a + * specific amount of stack space reserved outside of this. The number + * of bytes to be reserved is specified below. + */ + +int __STACKSIZE = 2048; |