diff options
| -rw-r--r-- | src/mesa/glapi/glapi.c | 44 |
1 files changed, 41 insertions, 3 deletions
diff --git a/src/mesa/glapi/glapi.c b/src/mesa/glapi/glapi.c index 563bfaefc98..b3f951a466b 100644 --- a/src/mesa/glapi/glapi.c +++ b/src/mesa/glapi/glapi.c @@ -1,4 +1,4 @@ -/* $Id: glapi.c,v 1.29 2000/01/28 20:17:42 brianp Exp $ */ +/* $Id: glapi.c,v 1.30 2000/01/31 22:51:44 brianp Exp $ */ /* * Mesa 3-D graphics library @@ -299,13 +299,51 @@ static GLuint NumExtEntryPoints = 0; /* * Generate a dispatch function (entrypoint) which jumps through * the given slot number (offset) in the current dispatch table. + * We need assembly language in order to accomplish this. */ static void * generate_entrypoint(GLuint offset) { - /* XXX need to generate some assembly code here */ - +#if defined(USE_X86_ASM) + /* + * This x86 code contributed by Josh Vanderhoof. + * + * 0: a1 10 32 54 76 movl __glapi_Dispatch,%eax + * 00 01 02 03 04 + * 5: 85 c0 testl %eax,%eax + * 05 06 + * 7: 74 06 je f <entrypoint+0xf> + * 07 08 + * 9: ff a0 10 32 54 76 jmp *0x76543210(%eax) + * 09 0a 0b 0c 0d 0e + * f: e8 fc ff ff ff call __glapi_get_dispatch + * 0f 10 11 12 13 + * 14: ff a0 10 32 54 76 jmp *0x76543210(%eax) + * 14 15 16 17 18 19 + */ + static const unsigned char temp[] = { + 0xa1, 0x00, 0x00, 0x00, 0x00, + 0x85, 0xc0, + 0x74, 0x06, + 0xff, 0xa0, 0x00, 0x00, 0x00, 0x00, + 0xe8, 0x00, 0x00, 0x00, 0x00, + 0xff, 0xa0, 0x00, 0x00, 0x00, 0x00 + }; + unsigned char *code = malloc(sizeof(temp)); + unsigned int next_insn; + if (code) { + memcpy(code, temp, sizeof(temp)); + + *(unsigned int *)(code + 0x01) = (unsigned int)&_glapi_Dispatch; + *(unsigned int *)(code + 0x0b) = (unsigned int)functionOffset * 4; + next_insn = (unsigned int)(code + 0x14); + *(unsigned int *)(code + 0x10) = (unsigned int)_glapi_get_dispatch - next_insn; + *(unsigned int *)(code + 0x16) = (unsigned int)functionOffset * 4; + } + return code; +#else return NULL; +#endif } |