From: Matthias Brugger <mbrugger@xxxxxxxx>
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@xxxxxxxxxxxxx>
Signed-off-by: Matthias Brugger <mbrugger@xxxxxxxx>
---
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
