On 19/04/15 22:36, Cormac O'Brien wrote:
Here's v2, with the debug macro untouched.
libopenbios/bootinfo_load.c | 100 +++++++++++++++++++++++++++++--------------- 1 file changed, 66 insertions(+), 34 deletions(-)
diff --git a/libopenbios/bootinfo_load.c b/libopenbios/bootinfo_load.c index fa9e36b..855b5dc 100644 --- a/libopenbios/bootinfo_load.c +++ b/libopenbios/bootinfo_load.c @@ -134,12 +134,13 @@ bootinfo_init_program(void) char *base; int proplen; phandle_t chosen;
- int tag, taglen, script, scriptlen, scriptvalid, entity, chrp;
- int tag, taglen, script, scriptind, scriptlen, scriptstart, scriptvalid,
entity, chrp;
Whitespace here.
char tagbuf[128], c; char *device, *filename, *directory, *partition; int current, size; char *bootscript;
char *tmp;
- char *tmp;
... and here.
char bootpath[1024];
/* Parse the boot script */ @@ -158,21 +159,14 @@ bootinfo_init_program(void) feval("load-base"); base = (char*)cell2pointer(POP());
- feval("load-size");
- size = POP();
- bootscript = malloc(size);
- if (bootscript == NULL) {
DPRINTF("Can't malloc %d bytes\n", size);return;- }
- if (!is_bootinfo(base)) { DPRINTF("Not a valid bootinfo memory image\n");
free(bootscript);
- feval("load-size");
- size = POP();
- chrp = 0; tag = 0; taglen = 0;
@@ -198,16 +192,10 @@ bootinfo_init_program(void) if (strncasecmp(tagbuf, "boot-script", 11) == 0) { script = 1; scriptlen = 0;
scriptstart = current; } else if (strncasecmp(tagbuf, "/boot-script", 12) == 0) {
script = 0;bootscript[scriptlen] = '\0';DPRINTF("got bootscript %s\n",bootscript);scriptvalid = -1;break; } else if (strncasecmp(tagbuf, "/chrp-boot", 10) == 0) break;@@ -217,42 +205,86 @@ bootinfo_init_program(void) } else if (script && c == '&') { entity = 1; taglen = 0;
} else if (entity && c ==';') {
} else if (entity && c == ';') { entity = 0; tagbuf[taglen] = '\0'; if (strncasecmp(tagbuf, "lt", 2) == 0) {
bootscript[scriptlen++] = '<';
scriptlen++; } else if (strncasecmp(tagbuf, "gt", 2) == 0) {
bootscript[scriptlen++] = '>';
scriptlen++; } else if (strncasecmp(tagbuf, "device", 6) == 0) {
strcpy(bootscript + scriptlen, device); scriptlen += strlen(device); } else if (strncasecmp(tagbuf, "partition", 9) == 0) {strcpy(bootscript + scriptlen, partition); scriptlen += strlen(partition); } else if (strncasecmp(tagbuf, "directory", 9) == 0) {strcpy(bootscript + scriptlen, directory); scriptlen += strlen(directory); } else if (strncasecmp(tagbuf, "filename", 8) == 0) {strcpy(bootscript + scriptlen, filename); scriptlen += strlen(filename); } else if (strncasecmp(tagbuf, "full-path", 9) == 0) {strcpy(bootscript + scriptlen, bootpath); scriptlen += strlen(bootpath);} else { /* unknown, keep it */bootscript[scriptlen] = '&';strcpy(bootscript + scriptlen + 1, tagbuf);scriptlen += taglen + 1;bootscript[scriptlen] = ';';scriptlen++;
} else {scriptlen += taglen + 2; }
bootscript[scriptlen++] = c;
scriptlen++;}}
bootscript = malloc(scriptlen * sizeof *bootscript + 1);
if (bootscript == NULL) {
DPRINTF("Can't malloc %d bytes\n", size);return;}
entity = 0;
scriptind = 0;
taglen = 0;
current = scriptstart;
while (current < scriptstart + scriptlen) {
c = base[current++];if (c == '&') {entity = 1;taglen = 0;} else if (entity && c == ';') {entity = 0;tagbuf[taglen] = '\0';if (strncasecmp(tagbuf, "lt", 2) == 0) {bootscript[scriptind++] = '<';} else if (strncasecmp(tagbuf, "gt", 2) == 0) {bootscript[scriptind++] = '>';} else if (strncasecmp(tagbuf, "device", 6) == 0) {strcpy(bootscript + scriptind, device);scriptind += strlen(device);} else if (strncasecmp(tagbuf, "partition", 9) == 0) {strcpy(bootscript + scriptind, partition);scriptind += strlen(partition);} else if (strncasecmp(tagbuf, "directory", 9) == 0) {strcpy(bootscript + scriptind, directory);scriptind += strlen(directory);} else if (strncasecmp(tagbuf, "filename", 8) == 0) {strcpy(bootscript + scriptind, filename);scriptlen += strlen(filename);} else if (strncasecmp(tagbuf, "full-path", 9) == 0) {strcpy(bootscript + scriptind, bootpath);scriptlen += strlen(bootscript);} else { /* unknown, keep it */bootscript[scriptind++] = '&';strcpy(bootscript + scriptind, tagbuf);scriptind += taglen;bootscript[scriptind++] = ';';}} else if (entity && taglen < sizeof(tagbuf)) {tagbuf[taglen++] = c;} else {bootscript[scriptind++] = c;} }
bootscript[scriptlen] = '\0';
/* If the payload is bootinfo then we execute it immediately */ if (scriptvalid) { DPRINTF("bootscript: %s\n", bootscript);
I haven't actually reworked the patch by hand in order to be able to apply directly, but the overall concept looks like it should work. Similar comments about whitespace and subject lines from the previous patch are also relevant here too - maybe libopenbios or bootcode_load.c as a subject prefix if you want to be a bit more more specific?
Part of me feels that this approach still requires quite a bit of refactoring of the existing code to accommodate this change. Thinking more succinctly, could the same effect be accomplished with something like this before the main while() loop (given that we know the entities will always take *less* space and EOT will never appear unencoded in the final output):
feval("load-size"); size = POP();
...
for (scriptlen = 0; scriptlen < size && base[scriptlen] != 0x4; scriptlen++);
...
Also a comment explaining that some boot scripts such as OS 9 add a binary payload after the chrp-boot script would be useful to explain to the casual code-dweller exactly why we are scanning the entire boot script as retrieved from disk first.
ATB,
Mark.