From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gregory CLEMENT Date: Fri, 30 Nov 2018 15:16:57 +0100 Subject: [U-Boot] [PATCH v2 7/7] MIPS: bootm: Add support for Vcore III linux kernel In-Reply-To: <4f5db2bd-fb75-d500-1b20-1a65dbe03eaa@gmail.com> (Daniel Schwierzeck's message of "Sun, 28 Oct 2018 18:54:02 +0100") References: <20181009115838.21795-1-gregory.clement@bootlin.com> <20181009115838.21795-8-gregory.clement@bootlin.com> <4f5db2bd-fb75-d500-1b20-1a65dbe03eaa@gmail.com> Message-ID: <87wooumyzq.fsf@bootlin.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Daniel, On dim., oct. 28 2018, Daniel Schwierzeck wrote: > Hi Gregory, > > sorry for the late response. > > Am 09.10.18 um 13:58 schrieb Gregory CLEMENT: >> The kernels built for the Vcore III linux kernel have different >> expectation in the way the data were passed. >> >> Unlike with yamon, the command line is expected to be a single string >> passed in argv[1]. An other expectation is that the arguments are located >> in the cached address space. > > I'm still not convinced whether this patch is necessary. As far as I > understand, you can boot a mainline kernel with the device-tree blob way > or with the legacy way. The latter makes sense when booting a mainline > kernel with Redboot. But what's the use case for booting a mainline > kernel in mainline U-Boot in the legacy way? Do you still want to boot > out-of-tree legacy kernels with mainline U-Boot? Currently there is only redboot which is used , but there is already mainline kernel in legacy format. The purpose of it, is to be able to switch from reboot to u-Boot but still being able to boot the mainline kernel currently used. As a bonus it could also allow to boot old out of tree kernel, but I don't think it is something planed. > > Apart from this is this single cmdline string specific to Redboot or > only to Microsemi? The former would be acceptable for a generic patch to Actually I don't know. > emulate a Redboot interface (similar to the YAMON one). But this should > be configurable for the user via Kconfig. You could enable this by > default with an "imply MIPS_BOOT_CMDLINE_REDBOOT" in your SoC/board > specific Kconfig part. > >> >> However, like yamon, they expect that rd_start and rd_size was passed by >> the bootloader in the command line of the kernel, and besides that it >> also wait for the root=/dev/ram0. > > Who exactly needs "root=/dev/ram0"? Normally the generic MIPS setup code > only needs "rd_start" and "rd_size" from cmdline respectively > "linux,initrd-start" and "linux,initrd-end" from the device-tree blob. If it is a problem I think that we can use a U-boot script to take care of this value. Gregory > >> >> Signed-off-by: Gregory CLEMENT >> --- >> arch/mips/lib/bootm.c | 77 ++++++++++++++++++++++++++++++++----------- >> 1 file changed, 57 insertions(+), 20 deletions(-) >> >> diff --git a/arch/mips/lib/bootm.c b/arch/mips/lib/bootm.c >> index deca5189e3..803d5e1de3 100644 >> --- a/arch/mips/lib/bootm.c >> +++ b/arch/mips/lib/bootm.c >> @@ -15,6 +15,11 @@ DECLARE_GLOBAL_DATA_PTR; >> #define LINUX_MAX_ENVS 256 >> #define LINUX_MAX_ARGS 256 >> >> +enum legacy_boot_type { >> + LEGACY_BOOT_YAML, >> + LEGACY_BOOT_VCORE, >> +}; >> + >> static int linux_argc; >> static char **linux_argv; >> static char *linux_argp; >> @@ -44,22 +49,46 @@ void arch_lmb_reserve(struct lmb *lmb) >> lmb_reserve(lmb, sp, gd->ram_top - sp); >> } >> >> -static void linux_cmdline_init(void) >> +static void linux_cmdline_init(enum legacy_boot_type boot_type) >> { >> + switch (boot_type) { >> + /* >> + * Vcore III linux kernels expect arguments in the cached >> + * address space. They also expect the command line being a >> + * single string in the first argument >> + */ >> + case LEGACY_BOOT_VCORE: >> + linux_argv = (char **)(gd->bd->bi_boot_params); >> + linux_argp = (char *)(linux_argv + LINUX_MAX_ARGS); >> + linux_argv[1] = linux_argp; >> + break; >> + case LEGACY_BOOT_YAML: >> + /* fallthrough */ >> + default: >> + linux_argv = (char **)UNCACHED_SDRAM(gd->bd->bi_boot_params); >> + linux_argp = (char *)(linux_argv + LINUX_MAX_ARGS); >> + } >> linux_argc = 1; >> - linux_argv = (char **)UNCACHED_SDRAM(gd->bd->bi_boot_params); >> linux_argv[0] = 0; >> - linux_argp = (char *)(linux_argv + LINUX_MAX_ARGS); >> } >> >> -static void linux_cmdline_set(const char *value, size_t len) >> +static void linux_cmdline_set(const char *value, size_t len, >> + enum legacy_boot_type boot_type) >> { >> - linux_argv[linux_argc] = linux_argp; >> memcpy(linux_argp, value, len); >> - linux_argp[len] = 0; >> - >> + switch (boot_type) { >> + case LEGACY_BOOT_VCORE: >> + linux_argv[linux_argc] = linux_argp; >> + linux_argp[len] = 0; >> + linux_argc++; >> + case LEGACY_BOOT_YAML: >> + /* fallthrough */ >> + default: >> + linux_argp[len] = ' '; >> + linux_argp[len + 1] = 0; >> + linux_argc = 2; >> + } >> linux_argp += len + 1; >> - linux_argc++; >> } >> >> static void linux_cmdline_dump(void) >> @@ -73,12 +102,11 @@ static void linux_cmdline_dump(void) >> debug(" arg %03d: %s\n", i, linux_argv[i]); >> } >> >> -static void linux_cmdline_legacy(bootm_headers_t *images) >> +static void linux_cmdline_legacy(bootm_headers_t *images, >> + enum legacy_boot_type boot_type) >> { >> const char *bootargs, *next, *quote; >> - >> - linux_cmdline_init(); >> - >> + linux_cmdline_init(boot_type); >> bootargs = env_get("bootargs"); >> if (!bootargs) >> return; >> @@ -104,7 +132,7 @@ static void linux_cmdline_legacy(bootm_headers_t *images) >> if (!next) >> next = bootargs + strlen(bootargs); >> >> - linux_cmdline_set(bootargs, next - bootargs); >> + linux_cmdline_set(bootargs, next - bootargs, boot_type); >> >> if (*next) >> next++; >> @@ -113,7 +141,8 @@ static void linux_cmdline_legacy(bootm_headers_t *images) >> } >> } >> >> -static void linux_cmdline_append(bootm_headers_t *images) >> +static void linux_cmdline_append(bootm_headers_t *images, >> + enum legacy_boot_type boot_type) >> { >> char buf[24]; >> ulong mem, rd_start, rd_size; >> @@ -121,7 +150,7 @@ static void linux_cmdline_append(bootm_headers_t *images) >> /* append mem */ >> mem = gd->ram_size >> 20; >> sprintf(buf, "mem=%luM", mem); >> - linux_cmdline_set(buf, strlen(buf)); >> + linux_cmdline_set(buf, strlen(buf), boot_type); >> >> /* append rd_start and rd_size */ >> rd_start = images->initrd_start; >> @@ -129,9 +158,13 @@ static void linux_cmdline_append(bootm_headers_t *images) >> >> if (rd_size) { >> sprintf(buf, "rd_start=0x%08lX", rd_start); >> - linux_cmdline_set(buf, strlen(buf)); >> + linux_cmdline_set(buf, strlen(buf), boot_type); >> sprintf(buf, "rd_size=0x%lX", rd_size); >> - linux_cmdline_set(buf, strlen(buf)); >> + linux_cmdline_set(buf, strlen(buf), boot_type); >> + if (boot_type == LEGACY_BOOT_VCORE) { >> + sprintf(buf, "root=/dev/ram0"); >> + linux_cmdline_set(buf, strlen(buf), boot_type); >> + } >> } >> } >> >> @@ -276,11 +309,15 @@ static void boot_prep_linux(bootm_headers_t *images) >> boot_reloc_fdt(images); >> boot_setup_fdt(images); >> } else { >> - if (CONFIG_IS_ENABLED(MIPS_BOOT_CMDLINE_LEGACY)) { >> - linux_cmdline_legacy(images); >> + if (CONFIG_IS_ENABLED(SOC_VCOREIII)) { >> + linux_cmdline_legacy(images, LEGACY_BOOT_VCORE); >> + linux_cmdline_append(images, LEGACY_BOOT_VCORE); >> + linux_cmdline_dump(); >> + } else if (CONFIG_IS_ENABLED(MIPS_BOOT_CMDLINE_LEGACY)) { >> + linux_cmdline_legacy(images, 0); >> >> if (!CONFIG_IS_ENABLED(MIPS_BOOT_ENV_LEGACY)) >> - linux_cmdline_append(images); >> + linux_cmdline_append(images, LEGACY_BOOT_YAML); >> >> linux_cmdline_dump(); >> } >> > > -- > - Daniel > -- Gregory Clement, Bootlin Embedded Linux and Kernel engineering http://bootlin.com