From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Glass Date: Fri, 26 Feb 2016 10:31:27 -0700 Subject: [U-Boot] [RFC PATCH v5 1/4] common: Convert ulong to phys_addr_t for image addresses In-Reply-To: References: <1456439779-4792-1-git-send-email-york.sun@nxp.com> <1456439779-4792-2-git-send-email-york.sun@nxp.com> <20160225230500.3FCAF3809F9@gemini.denx.de> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi York, On 26 February 2016 at 10:22, york sun wrote: > On 02/25/2016 03:05 PM, Wolfgang Denk wrote: >> Dear York Sun, >> >> In message <1456439779-4792-2-git-send-email-york.sun@nxp.com> you wrote: >>> When dealing with image addresses, ulong has been used. Some files >>> are used by both host and target. It is OK for the target, but not >>> always enough for host tools including mkimage. This patch replaces >>> "ulong" with "phys_addr_t" to make sure addresses are correct for >>> both the target and the host. >> >> You talk here about using "phys_addr_t"... >> >>> - ulong, ulong, ulong))images->ep; >>> + ulong, ulong, ulong))(uintptr_t)images->ep; >> >> ...but here you use uintptr_t , hich is something different? >> >>> - ulong, ulong, ulong))images->ep)(images->ft_addr, >>> + ulong, ulong, ulong))(uintptr_t)images->ep)(images->ft_addr, >> >> Ditto. >> >>> + phys_addr_t os_data; >>> + ulong os_len; >>> void *data = NULL; >>> size_t len; >>> int ret; >>> @@ -87,11 +89,10 @@ static int boot_prep_linux(bootm_headers_t *images) >>> if (images->legacy_hdr_valid) { >>> hdr = images->legacy_hdr_os; >>> if (image_check_type(hdr, IH_TYPE_MULTI)) { >>> - ulong os_data, os_len; >> >> Why do you moe the declarations out of this block? The variables are >> only used within this block so there is no need for a wider scope? >> >>> - data = (void *)os_data; >>> + data = (void *)(uintptr_t)os_data; >> >> This double cast looks scary to me, and you don;t explain it in the >> commit message. Why exactly is this needed? >> >>> - cmd_line_dest = (void *)images->ep + COMMAND_LINE_OFFSET; >>> + cmd_line_dest = (void *)(uintptr_t)images->ep + >>> + COMMAND_LINE_OFFSET; >> >> Ditto. >> >>> - printf("Setup at %#08lx\n", images->ep); >>> - ret = setup_zimage((void *)images->ep, cmd_line_dest, >>> + printf("Setup at %#08" PRIpa "\n", images->ep); >> >> This is really ugly... >> >>> + ret = setup_zimage((void *)(uintptr_t)images->ep, cmd_line_dest, >> >> See before. >> >>> - debug("## Transferring control to Linux (at address %08lx, kernel %08lx) ...\n", >>> + debug("## Transferring control to Linux (at address %#08" PRIpa >>> + ", kernel %#08" PRIpa ") ...\n", >> >> See before... >> >>> - debug("* kernel: cmdline image address = 0x%08lx\n", >>> - images->ep); >>> + debug("* kernel: cmdline image address = %#08" PRIpa "\n", >>> + images->ep); >> >> Ditto. etc. etc. >> >>> + /* >>> + * In this function, data is decalred as phys_addr_t type. >> >> s/decalred/declared/ >> >>> + * On some systems (eg. ARM, PowerPC) phys_addr_t can be >>> + * "unsigned long", or "unsigned long long", depending on >>> + * CONFIG_PHYS_64BIT. It is safe to cast 64-bit phys_addr_t >>> + * to 32-bit pointer for image handling because the actual >>> + * address the image is loaded is within 32-bit space. >> >> Who guarantees that? >> >>> - data = (ulong)fit_data; >>> + data = (phys_addr_t)(uintptr_t)fit_data; >> >> This double cast looks strange to me. Why is it needed? >> >>> - void *from = (void *)data; >>> + void *from = (void *)(uintptr_t)data; >> >> Ditto. >> >>> - memmove((char *) dest, (char *)data, len); >>> + memmove((char *)dest, (char *)(uintptr_t)data, len); >> >> Ditto. etc. etc. >> >> >> All these double casts look somewhat wrong to me. Why are they >> needed? > > Dear Wolfgang, > > I can use some serious help here. What I am really trying to achieve is the last > two patches in this set. I didn't want to use replace ulong with phys_addr_t. I > am not proud with the change I proposed, but I didn't come up with a smarter > solution. My specific trouble is to build ARMv8 targets on 32-bit Ubuntu host. > Some code is shared between the target and host tool (mkimage). I started from > small changes, but it gets wider and wider when I tried to get rid of the > compiling warnings. > > York > I suggest just documenting it better with comments and in the commit message. It's mostly the same comment I made. One concern is that if you cast to uintptr_t on a 32-bit host machine, won't you end up dropping the top 32 bits? Regards, Simon