assembly - INT 13h, get status of last op -


i'm writing bootloader bios in 16-bit real mode, using qemu emulator.

i have code fails read hd. that's ok, bothers me when try status code operation using "get status of last drive operation".

according this wikipedia resource, can set ah 1, , set dl desired drive (which i've verified 0x80). then, when invoke int 13h, al should have status code in it.

however, when this, carry flag gets set, indicating attempt read status failed.

other specifying wrong drive, don't see how possibly fail.

so question is, what ways command (int 13h, ah 01h) possibly fail?

here's code:

get_status:     mov ah, 0x01    ; status fxn     mov dl, 0x80    ; 0x80 our drive     int 0x13        ; call fxn      jc print_status_failure     jmp $  print_status_failure:     mov ax, fail_msg     call print_string     jmp $

then, when invoke int 13h, al should have status code in it.

bios function 01h int 13h returns result in ah register. carry flag not defined , should never test failure after having invoked function!


-

Comments

Post a Comment

Popular posts from this blog

apache - PHP Soap issue while content length is larger -

we have developed soap based webservice post data third party webservice. accepts 4 params. in 1 of parameters accepts xml string no size limit restriction put in place. the webservice works fine in local environment running on php 5.2 , apache2. works content length long 10 mb. in staging server running nginx , php fpm.we have updated max post size , max upload filesize in php.ini , client_max_body param in nginx.conf allow upto 50 mb. but webservice client keeps on loading in staging environment. gives 502 timeout , gives soap error. can me understand issue here?
Read more

asynchronous - Python asyncio task got bad yield -

i confused how play around asyncio module in python 3.4. have searching api search engine, , want each search request run either parallel, or asynchronously, don't have wait 1 search finish start another. here high-level searching api build objects raw search results. search engine using kind of asyncio mechanism, won't bother that. # no asyncio module used here class search(object): ... self.s = some_search_engine() ... def searching(self, *args, **kwargs): ret = {} # raw searching according args , kwargs , build wrapped results ... return ret to try async requests, wrote following test case test how can interact stuff asyncio module. # here testing script @asyncio.coroutine def handle(f, *args, **kwargs): r = yield f(*args, **kwargs) return r s = search() loop = asyncio.get_event_loop() loop.run_until_complete(handle(s.searching, arg1, arg2, ...)) loop.close() by running pytest, return runtimeerror: task got bad yield : {results s...
Read more

javascript - Complete OpenIDConnect auth when requesting via Ajax -

the normal openidconnect server works like: you go a.com/secure-resource you 302 server your browser handles , sends identity server you login there it sends a.com via post you logged in on a.com , a.com/secure-resource on browser. however have scenario i'm trying solve need help. the user logged in on idserver the user logged in on a.com the user not logged in on b.com we need send ajax call web server b.com (from domain a.com ) b.com configured use openidconnect. but because request b.com via ajax, user cannot redirected idserver. (all in response 302 ) we can go ahead , handle 302 via ajax (i'm still not sure whether work, security-wise). but is there scenario in identityserver/openidconnect designed these situations? with identityserver in scenario setup server b.com use bearer token authentication, need use access token provided a.com in headers of ajax call $.ajax({ url: 'http://b.com', headers: { ...
Read more