Date: Thu, 7 Jun 2012 00:26:18 -0600 From: Warner Losh <imp@bsdimp.com> To: "arm@freebsd.org" <arm@freebsd.org> Subject: Boot parameter parsing Message-ID: <FB34C0E8-2C1D-4758-A8AC-DC090C009B44@bsdimp.com>
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--Apple-Mail-28--34073920 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Greetings, Please find enclosed a small patch to the arm port. For too long parsing boot args in arm land has suffered from cut and = paste code. This is inefficient and inflexible. This patch does = something to fix that. First, it modifies all the arm ports to call = parse_boot_param passing in the boot parameters from initarm as the = first thing in each platform's implementation of that function. This is = done really super early, importantly before we start using memory = outside of the loaded kernel's text, data, and bss areas. I'd thought = of moving this even earlier, into __start just before the call to = initarm, but wasn't completely sure was quite right (it would be more = code deleted, however, if I do that: please comment). The down side is = that initarm was the only function we called in __start apart from = mundane things like memcpy and that would change that, but that's kinda = a weak argument I think. I've created a weak alias to tying this function to = fake_preload_metadata. All but one of the ports do this now, and this = moves them to a common standard that could be more easily changed. For most ports, it replaces the call to fake_preload_metadata. As such, = I've modified the signature of fake_preload_metadata to be the same as = parse_boot_param and made it a weak alias. So, if you don't define one, = you'll get the current behavior. In a future patch, I'll likely be moving the mv platform's code into = this routine (I'll create a default_parse_boot_param and create a weak = alias pointing to that instead). I'll need to modify the mv port to = then get the dtb blob via the metadata, or possibly create a new global = for it so that other platforms might make use of that also. In a patch after that, I may add a kernel option to enable creation of = FreeBSD /boot/loader metadata from Linux's standard boot stuff. This = will allow platforms to get more data from the Linux boot loader without = going through the intermediate /boot/loader. But it should preserve a = unified interface by having it behave just like /boot/loader, but = without anything setup by its more advanced features like kernel = environment variables or loadable modules. If I've done things right by this point, then any ARM port can take = advantage of these new features, not just the target I'm aiming at. In = addition, anybody can use their own boot loader, if they so choose, and = be able to write custom code that parses the args from it in whatever = appropriate way might arise for their board. I know of at least one = FreeBSD/arm user that has a heavily hacked boot2 boot loader that passes = things into the kernel in a non-standard way. This will accommodate = them, and others like them, while still providing the project with = useful functionality. Comments? Warner P.S. You can also find this at = http://people.freebsd.org/~imp/parse_boot_param.diff in case the mailing = list eats this for lunch. --Apple-Mail-28--34073920 Content-Disposition: attachment; filename=parse_boot_param.diff Content-Type: application/octet-stream; name="parse_boot_param.diff" Content-Transfer-Encoding: 7bit Index: sys/arm/arm/machdep.c =================================================================== --- sys/arm/arm/machdep.c (revision 236701) +++ sys/arm/arm/machdep.c (working copy) @@ -664,7 +664,7 @@ * Fake up a boot descriptor table */ vm_offset_t -fake_preload_metadata(void) +fake_preload_metadata(struct arm_boot_params *abp __unused) { #ifdef DDB vm_offset_t zstart = 0, zend = 0; @@ -709,3 +709,20 @@ return (lastaddr); } + +/* + * Stub version of the boot parameter parsing routine. We are + * called early in initarm, before even VM has been initialized. + * This routine needs to preserve any data that the boot loader + * has passed in before the kernel starts to grow past the end + * of the BSS, traditionally the place boot-loaders put this data. + * + * Since this is called so early, things that depend on the vm system + * being setup (including access to some SoC's serial ports), about + * all that can be done in this routine is to copy the arguments. + * + * This is the default boot parameter parsing routine. Individual + * kernels/boards can override this weak function with one of their + * own. We just fake metadata... + */ +__weak_reference(fake_preload_metadata, parse_boot_param); Index: sys/arm/xscale/i8134x/crb_machdep.c =================================================================== --- sys/arm/xscale/i8134x/crb_machdep.c (revision 236701) +++ sys/arm/xscale/i8134x/crb_machdep.c (working copy) @@ -191,8 +191,8 @@ vm_offset_t lastaddr; uint32_t memsize, memstart; + lastaddr = parse_boot_param(abp); set_cpufuncs(); - lastaddr = fake_preload_metadata(); pcpu_init(pcpup, 0, sizeof(struct pcpu)); PCPU_SET(curthread, &thread0); Index: sys/arm/xscale/i80321/ep80219_machdep.c =================================================================== --- sys/arm/xscale/i80321/ep80219_machdep.c (revision 236701) +++ sys/arm/xscale/i80321/ep80219_machdep.c (working copy) @@ -194,8 +194,8 @@ vm_offset_t lastaddr; uint32_t memsize, memstart; + lastaddr = parse_boot_param(abp); set_cpufuncs(); - lastaddr = fake_preload_metadata(); pcpu_init(pcpup, 0, sizeof(struct pcpu)); PCPU_SET(curthread, &thread0); Index: sys/arm/xscale/i80321/iq31244_machdep.c =================================================================== --- sys/arm/xscale/i80321/iq31244_machdep.c (revision 236701) +++ sys/arm/xscale/i80321/iq31244_machdep.c (working copy) @@ -195,8 +195,8 @@ vm_offset_t lastaddr; uint32_t memsize, memstart; + lastaddr = parse_boot_param(abp); set_cpufuncs(); - lastaddr = fake_preload_metadata(); pcpu_init(pcpup, 0, sizeof(struct pcpu)); PCPU_SET(curthread, &thread0); Index: sys/arm/xscale/pxa/pxa_machdep.c =================================================================== --- sys/arm/xscale/pxa/pxa_machdep.c (revision 236701) +++ sys/arm/xscale/pxa/pxa_machdep.c (working copy) @@ -176,9 +176,8 @@ int i, j; uint32_t memsize[PXA2X0_SDRAM_BANKS], memstart[PXA2X0_SDRAM_BANKS]; + lastaddr = parse_boot_param(abp); set_cpufuncs(); - - lastaddr = fake_preload_metadata(); pcpu_init(pcpup, 0, sizeof(struct pcpu)); PCPU_SET(curthread, &thread0); Index: sys/arm/xscale/ixp425/avila_machdep.c =================================================================== --- sys/arm/xscale/ixp425/avila_machdep.c (revision 236701) +++ sys/arm/xscale/ixp425/avila_machdep.c (working copy) @@ -240,8 +240,8 @@ vm_offset_t lastaddr; uint32_t memsize; + lastaddr = parse_boot_param(abp); set_cpufuncs(); /* NB: sets cputype */ - lastaddr = fake_preload_metadata(); pcpu_init(pcpup, 0, sizeof(struct pcpu)); PCPU_SET(curthread, &thread0); Index: sys/arm/mv/mv_machdep.c =================================================================== --- sys/arm/mv/mv_machdep.c (revision 236701) +++ sys/arm/mv/mv_machdep.c (working copy) @@ -333,7 +333,7 @@ */ mdp = (void *)((uint32_t)mdp & ~PAGE_MASK); - /* Parse metadata and fetch parameters */ + /* Parse metadata and fetch parameters (move to common machdep.c?) */ if (mdp != NULL) { preload_metadata = mdp; kmdp = preload_search_by_type("elf kernel"); @@ -352,7 +352,7 @@ preload_addr_relocate = KERNVIRTADDR - KERNPHYSADDR; } else { /* Fall back to hardcoded metadata. */ - lastaddr = fake_preload_metadata(); + lastaddr = fake_preload_metadata(abp); } #if defined(FDT_DTB_STATIC) Index: sys/arm/include/machdep.h =================================================================== --- sys/arm/include/machdep.h (revision 236701) +++ sys/arm/include/machdep.h (working copy) @@ -6,10 +6,12 @@ /* misc prototypes used by the many arm machdeps */ void arm_lock_cache_line(vm_offset_t); -vm_offset_t fake_preload_metadata(void); void halt(void); void data_abort_handler(trapframe_t *); void prefetch_abort_handler(trapframe_t *); void undefinedinstruction_bounce(trapframe_t *); +struct arm_boot_params; +vm_offset_t parse_boot_param(struct arm_boot_params *abp); +vm_offset_t fake_preload_metadata(struct arm_boot_params *abp); #endif /* !_MACHINE_MACHDEP_H_ */ Index: sys/arm/econa/econa_machdep.c =================================================================== --- sys/arm/econa/econa_machdep.c (revision 236701) +++ sys/arm/econa/econa_machdep.c (working copy) @@ -197,8 +197,8 @@ boothowto = RB_VERBOSE; + lastaddr = parse_boot_param(abp); set_cpufuncs(); - lastaddr = fake_preload_metadata(); pcpu_init(pcpup, 0, sizeof(struct pcpu)); PCPU_SET(curthread, &thread0); Index: sys/arm/s3c2xx0/s3c24x0_machdep.c =================================================================== --- sys/arm/s3c2xx0/s3c24x0_machdep.c (revision 236701) +++ sys/arm/s3c2xx0/s3c24x0_machdep.c (working copy) @@ -246,10 +246,9 @@ int i; uint32_t memsize; + boothowto = 0; /* Likely not needed */ + lastaddr = parse_boot_param(abp); i = 0; - - boothowto = 0; - set_cpufuncs(); cpufuncs.cf_sleep = s3c24x0_sleep; lastaddr = fake_preload_metadata(); Index: sys/arm/sa11x0/assabet_machdep.c =================================================================== --- sys/arm/sa11x0/assabet_machdep.c (revision 236701) +++ sys/arm/sa11x0/assabet_machdep.c (working copy) @@ -216,10 +216,10 @@ uint32_t memsize = 32 * 1024 * 1024; sa1110_uart_vaddr = SACOM1_VBASE; - boothowto = RB_VERBOSE | RB_SINGLE; + boothowto = RB_VERBOSE | RB_SINGLE; /* Default value */ + lastaddr = parse_boot_param(abp); cninit(); set_cpufuncs(); - lastaddr = fake_preload_metadata(); physmem = memsize / PAGE_SIZE; pc = &__pcpu; pcpu_init(pc, 0, sizeof(struct pcpu)); Index: sys/arm/at91/at91_machdep.c =================================================================== --- sys/arm/at91/at91_machdep.c (revision 236701) +++ sys/arm/at91/at91_machdep.c (working copy) @@ -394,8 +394,8 @@ uint32_t memsize; vm_offset_t lastaddr; + lastaddr = parse_boot_param(abp); set_cpufuncs(); - lastaddr = fake_preload_metadata(); pcpu_init(pcpup, 0, sizeof(struct pcpu)); PCPU_SET(curthread, &thread0); --Apple-Mail-28--34073920 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii --Apple-Mail-28--34073920--
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