[PATCH v4] arm64: Add purgatory printing
Simon Horman
horms at verge.net.au
Fri Oct 23 05:51:18 EDT 2020
On Fri, Oct 16, 2020 at 01:40:57PM +0200, Matthias Brugger wrote:
> Hi,
>
> On 02/10/2020 20:34, Bhupesh Sharma wrote:
> > Hello Matthias,
> >
> > Thanks for the updated revision.
> >
> > On Fri, Oct 2, 2020 at 7:13 PM <matthias.bgg at kernel.org> wrote:
> > >
> > > From: Matthias Brugger <mbrugger at suse.com>
> > >
> > > Add option to allow purgatory printing on arm64 hardware
> > > by passing the console name which should be used.
> > > Based on a patch by Geoff Levand.
> > >
> > > Cc: Geoff Levand <geoff at infradead.org>
> > > Signed-off-by: Matthias Brugger <mbrugger at suse.com>
> > >
> > > ---
> > >
> > > Changes in v4:
> > > - fix snprintf error handling
> > >
> > > Changes in v3:
> > > - check return value of snprintf
> > >
> > > Changes in v2:
> > > - use sizeof(buffer)
> > > - user serial command option instead of console
> > > - reduce buffer to size 10
> > > - use snprintf
> > > - fix error handling for wrong serial console parameter
> > > - Update help information
> > >
> > > kexec/arch/arm64/include/arch/options.h | 6 ++-
> > > kexec/arch/arm64/kexec-arm64.c | 71 +++++++++++++++++++++++++
> > > purgatory/arch/arm64/purgatory-arm64.c | 17 +++++-
> > > 3 files changed, 92 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/kexec/arch/arm64/include/arch/options.h b/kexec/arch/arm64/include/arch/options.h
> > > index a17d933..8c695f3 100644
> > > --- a/kexec/arch/arm64/include/arch/options.h
> > > +++ b/kexec/arch/arm64/include/arch/options.h
> > > @@ -5,7 +5,8 @@
> > > #define OPT_DTB ((OPT_MAX)+1)
> > > #define OPT_INITRD ((OPT_MAX)+2)
> > > #define OPT_REUSE_CMDLINE ((OPT_MAX)+3)
> > > -#define OPT_ARCH_MAX ((OPT_MAX)+4)
> > > +#define OPT_SERIAL ((OPT_MAX)+4)
> > > +#define OPT_ARCH_MAX ((OPT_MAX)+5)
> > >
> > > #define KEXEC_ARCH_OPTIONS \
> > > KEXEC_OPTIONS \
> > > @@ -13,6 +14,7 @@
> > > { "command-line", 1, NULL, OPT_APPEND }, \
> > > { "dtb", 1, NULL, OPT_DTB }, \
> > > { "initrd", 1, NULL, OPT_INITRD }, \
> > > + { "serial", 1, NULL, OPT_SERIAL }, \
> > > { "ramdisk", 1, NULL, OPT_INITRD }, \
> > > { "reuse-cmdline", 0, NULL, OPT_REUSE_CMDLINE }, \
> > >
> > > @@ -25,6 +27,7 @@ static const char arm64_opts_usage[] __attribute__ ((unused)) =
> > > " --command-line=STRING Set the kernel command line to STRING.\n"
> > > " --dtb=FILE Use FILE as the device tree blob.\n"
> > > " --initrd=FILE Use FILE as the kernel initial ramdisk.\n"
> > > +" --serial=STRING Name of console used for purgatory printing. (e.g. ttyAMA0)\n"
> > > " --ramdisk=FILE Use FILE as the kernel initial ramdisk.\n"
> > > " --reuse-cmdline Use kernel command line from running system.\n";
> > >
> > > @@ -32,6 +35,7 @@ struct arm64_opts {
> > > const char *command_line;
> > > const char *dtb;
> > > const char *initrd;
> > > + const char *console;
> > > };
> > >
> > > extern struct arm64_opts arm64_opts;
> > > diff --git a/kexec/arch/arm64/kexec-arm64.c b/kexec/arch/arm64/kexec-arm64.c
> > > index 45ebc54..6f572ed 100644
> > > --- a/kexec/arch/arm64/kexec-arm64.c
> > > +++ b/kexec/arch/arm64/kexec-arm64.c
> > > @@ -165,6 +165,8 @@ int arch_process_options(int argc, char **argv)
> > > break;
> > > case OPT_KEXEC_FILE_SYSCALL:
> > > do_kexec_file_syscall = 1;
> > > + case OPT_SERIAL:
> > > + arm64_opts.console = optarg;
> > > break;
> > > default:
> > > break; /* Ignore core and unknown options. */
> > > @@ -180,12 +182,72 @@ int arch_process_options(int argc, char **argv)
> > > dbgprintf("%s:%d: dtb: %s\n", __func__, __LINE__,
> > > (do_kexec_file_syscall && arm64_opts.dtb ? "(ignored)" :
> > > arm64_opts.dtb));
> > > + dbgprintf("%s:%d: console: %s\n", __func__, __LINE__,
> > > + arm64_opts.console);
> > > +
> > > if (do_kexec_file_syscall)
> > > arm64_opts.dtb = NULL;
> > >
> > > return 0;
> > > }
> > >
> > > +/**
> > > + * find_purgatory_sink - Find a sink for purgatory output.
> > > + */
> > > +
> > > +static uint64_t find_purgatory_sink(const char *console)
> > > +{
> > > + int fd, ret;
> > > + char device[255], mem[255];
> > > + struct stat sb;
> > > + char buffer[10];
> > > + uint64_t iomem = 0x0;
> > > +
> > > + if (!console)
> > > + return 0;
> > > +
> > > + ret = snprintf(device, sizeof(device), "/sys/class/tty/%s", console);
> > > + if (ret < 0 || ret >= sizeof(device)) {
> > > + fprintf(stderr, "snprintf failed: %s\n", strerror(errno));
> > > + return 0;
> > > + }
> > > +
> > > + if (stat(device, &sb) || !S_ISDIR(sb.st_mode)) {
> > > + fprintf(stderr, "kexec: %s: No valid console found for %s\n",
> > > + __func__, device);
> > > + return 0;
> > > + }
> > > +
> > > + ret = snprintf(mem, sizeof(mem), "%s%s", device, "/iomem_base");
> > > + if (ret < 0 || ret >= sizeof(mem)) {
> > > + fprintf(stderr, "snprintf failed: %s\n", strerror(errno));
> > > + return 0;
> > > + }
> > > +
> > > + printf("console memory read from %s\n", mem);
> > > +
> > > + fd = open(mem, O_RDONLY);
> > > + if (fd < 0) {
> > > + fprintf(stderr, "kexec: %s: No able to open %s\n",
> > > + __func__, mem);
> > > + return 0;
> > > + }
> > > +
> > > + memset(buffer, '\0', sizeof(buffer));
> > > + ret = read(fd, buffer, sizeof(buffer));
> > > + if (ret < 0) {
> > > + fprintf(stderr, "kexec: %s: not able to read fd\n", __func__);
> > > + close(fd);
> > > + return 0;
> > > + }
> > > +
> > > + sscanf(buffer, "%lx", &iomem);
> > > + printf("console memory is at %#lx\n", iomem);
> > > +
> > > + close(fd);
> > > + return iomem;
> > > +}
> > > +
> > > /**
> > > * struct dtb - Info about a binary device tree.
> > > *
> > > @@ -637,6 +699,7 @@ int arm64_load_other_segments(struct kexec_info *info,
> > > unsigned long hole_min;
> > > unsigned long hole_max;
> > > unsigned long initrd_end;
> > > + uint64_t purgatory_sink;
> > > char *initrd_buf = NULL;
> > > struct dtb dtb;
> > > char command_line[COMMAND_LINE_SIZE] = "";
> > > @@ -654,6 +717,11 @@ int arm64_load_other_segments(struct kexec_info *info,
> > > command_line[sizeof(command_line) - 1] = 0;
> > > }
> > >
> > > + purgatory_sink = find_purgatory_sink(arm64_opts.console);
> > > +
> > > + dbgprintf("%s:%d: purgatory sink: 0x%" PRIx64 "\n", __func__, __LINE__,
> > > + purgatory_sink);
> > > +
> > > if (arm64_opts.dtb) {
> > > dtb.name = "dtb_user";
> > > dtb.buf = slurp_file(arm64_opts.dtb, &dtb.size);
> > > @@ -742,6 +810,9 @@ int arm64_load_other_segments(struct kexec_info *info,
> > >
> > > info->entry = (void *)elf_rel_get_addr(&info->rhdr, "purgatory_start");
> > >
> > > + elf_rel_set_symbol(&info->rhdr, "arm64_sink", &purgatory_sink,
> > > + sizeof(purgatory_sink));
> > > +
> > > elf_rel_set_symbol(&info->rhdr, "arm64_kernel_entry", &image_base,
> > > sizeof(image_base));
> > >
> > > diff --git a/purgatory/arch/arm64/purgatory-arm64.c b/purgatory/arch/arm64/purgatory-arm64.c
> > > index fe50fcf..b4d8578 100644
> > > --- a/purgatory/arch/arm64/purgatory-arm64.c
> > > +++ b/purgatory/arch/arm64/purgatory-arm64.c
> > > @@ -5,15 +5,30 @@
> > > #include <stdint.h>
> > > #include <purgatory.h>
> > >
> > > +/* Symbols set by kexec. */
> > > +
> > > +uint8_t *arm64_sink __attribute__ ((section ("data")));
> > > +extern void (*arm64_kernel_entry)(uint64_t, uint64_t, uint64_t, uint64_t);
> > > +extern uint64_t arm64_dtb_addr;
> > > +
> > > void putchar(int ch)
> > > {
> > > - /* Nothing for now */
> > > + if (!arm64_sink)
> > > + return;
> > > +
> > > + *arm64_sink = ch;
> > > +
> > > + if (ch == '\n')
> > > + *arm64_sink = '\r';
> > > }
> > >
> > > void post_verification_setup_arch(void)
> > > {
> > > + printf("purgatory: booting kernel now\n");
> > > }
> > >
> > > void setup_arch(void)
> > > {
> > > + printf("purgatory: entry=%lx\n", (unsigned long)arm64_kernel_entry);
> > > + printf("purgatory: dtb=%lx\n", arm64_dtb_addr);
> > > }
> > > --
> > > 2.28.0
> >
> > Looks good to me, so:
> > Acked-by: Bhupesh Sharma <bhsharma at redhat.com>
> >
>
> Simon: friendly reminder of this patch. Please let me know if you have any
> concerns regarding the patch.
>
> Best regards,
> Matthias
>
Sorry for the extended delay,
I've applied and pushed this change.
More information about the kexec
mailing list