diff options
Diffstat (limited to 'contrib/syslinux/syslinux-4.03/com32/lib/malloc.c')
| -rw-r--r-- | contrib/syslinux/syslinux-4.03/com32/lib/malloc.c | 156 |
1 files changed, 0 insertions, 156 deletions
diff --git a/contrib/syslinux/syslinux-4.03/com32/lib/malloc.c b/contrib/syslinux/syslinux-4.03/com32/lib/malloc.c deleted file mode 100644 index ec103ab..0000000 --- a/contrib/syslinux/syslinux-4.03/com32/lib/malloc.c +++ /dev/null @@ -1,156 +0,0 @@ -/* - * malloc.c - * - * Very simple linked-list based malloc()/free(). - */ - -#include <stdlib.h> -#include <string.h> -#include <com32.h> -#include <syslinux/memscan.h> -#include "init.h" -#include "malloc.h" - -struct free_arena_header __malloc_head = { - { - ARENA_TYPE_HEAD, - 0, - &__malloc_head, - &__malloc_head, - }, - &__malloc_head, - &__malloc_head -}; - -/* This is extern so it can be overridden by the user application */ -extern size_t __stack_size; -extern void *__mem_end; /* Produced after argv parsing */ - -static inline size_t sp(void) -{ - size_t sp; - asm volatile ("movl %%esp,%0":"=rm" (sp)); - return sp; -} - -#define E820_MEM_MAX 0xfff00000 /* 4 GB - 1 MB */ - -static int consider_memory_area(void *dummy, addr_t start, - addr_t len, bool valid) -{ - struct free_arena_header *fp; - addr_t end; - - (void)dummy; - - if (valid && start < E820_MEM_MAX) { - if (len > E820_MEM_MAX - start) - len = E820_MEM_MAX - start; - - end = start + len; - - if (end > __com32.cs_memsize) { - if (start <= __com32.cs_memsize) { - start = __com32.cs_memsize; - len = end - start; - } - - if (len >= 2 * sizeof(struct arena_header)) { - fp = (struct free_arena_header *)start; - fp->a.size = len; - __inject_free_block(fp); - } - } - } - - return 0; -} - -static void __constructor init_memory_arena(void) -{ - struct free_arena_header *fp; - size_t start, total_space; - - start = (size_t) ARENA_ALIGN_UP(__mem_end); - total_space = sp() - start; - - if (__stack_size == 0 || __stack_size > total_space >> 1) - __stack_size = total_space >> 1; /* Half for the stack, half for the heap... */ - - if (total_space < __stack_size + 4 * sizeof(struct arena_header)) - __stack_size = total_space - 4 * sizeof(struct arena_header); - - fp = (struct free_arena_header *)start; - fp->a.size = total_space - __stack_size; - - __inject_free_block(fp); - - /* Scan the memory map to look for other suitable regions */ - if (!__com32.cs_memsize) - return; /* Old Syslinux core, can't do this... */ - - syslinux_scan_memory(consider_memory_area, NULL); -} - -static void *__malloc_from_block(struct free_arena_header *fp, size_t size) -{ - size_t fsize; - struct free_arena_header *nfp, *na; - - fsize = fp->a.size; - - /* We need the 2* to account for the larger requirements of a free block */ - if (fsize >= size + 2 * sizeof(struct arena_header)) { - /* Bigger block than required -- split block */ - nfp = (struct free_arena_header *)((char *)fp + size); - na = fp->a.next; - - nfp->a.type = ARENA_TYPE_FREE; - nfp->a.size = fsize - size; - fp->a.type = ARENA_TYPE_USED; - fp->a.size = size; - - /* Insert into all-block chain */ - nfp->a.prev = fp; - nfp->a.next = na; - na->a.prev = nfp; - fp->a.next = nfp; - - /* Replace current block on free chain */ - nfp->next_free = fp->next_free; - nfp->prev_free = fp->prev_free; - fp->next_free->prev_free = nfp; - fp->prev_free->next_free = nfp; - } else { - /* Allocate the whole block */ - fp->a.type = ARENA_TYPE_USED; - - /* Remove from free chain */ - fp->next_free->prev_free = fp->prev_free; - fp->prev_free->next_free = fp->next_free; - } - - return (void *)(&fp->a + 1); -} - -void *malloc(size_t size) -{ - struct free_arena_header *fp; - - if (size == 0) - return NULL; - - /* Add the obligatory arena header, and round up */ - size = (size + 2 * sizeof(struct arena_header) - 1) & ARENA_SIZE_MASK; - - for (fp = __malloc_head.next_free; fp->a.type != ARENA_TYPE_HEAD; - fp = fp->next_free) { - if (fp->a.size >= size) { - /* Found fit -- allocate out of this block */ - return __malloc_from_block(fp, size); - } - } - - /* Nothing found... need to request a block from the kernel */ - return NULL; /* No kernel to get stuff from */ -} |