Previous transmission must be completed before next character to be
transmitted, otherwise TX buffer may saturate and we will not see all
the characters on screen.
Signed-off-by: Pratyush Anand <panand at redhat.com>
---
kexec/arch/arm64/include/arch/options.h | 10 +++++++++-
kexec/arch/arm64/kexec-arm64.c | 17 +++++++++++++++++
purgatory/arch/arm64/entry.S | 10 ++++++++++
purgatory/arch/arm64/purgatory-arm64.c | 22 +++++++++++++++++++++-
4 files changed, 57 insertions(+), 2 deletions(-)
diff --git a/kexec/arch/arm64/include/arch/options.h b/kexec/arch/arm64/include/arch/options.h
index af14102220ea..a1f6f2cb00be 100644
--- a/kexec/arch/arm64/include/arch/options.h
+++ b/kexec/arch/arm64/include/arch/options.h
@@ -8,7 +8,9 @@
#define OPT_PAGE_OFFSET ((OPT_MAX)+4)
#define OPT_PORT ((OPT_MAX)+5)
#define OPT_REUSE_CMDLINE ((OPT_MAX+6))
-#define OPT_ARCH_MAX ((OPT_MAX)+7)
+#define OPT_PORT_LSR ((OPT_MAX)+7)
+#define OPT_PORT_LSR_VAL ((OPT_MAX)+8)
+#define OPT_ARCH_MAX ((OPT_MAX)+9)
#define KEXEC_ARCH_OPTIONS \
KEXEC_OPTIONS \
@@ -19,6 +21,8 @@
{ "lite", 0, NULL, OPT_LITE }, \
{ "page-offset", 1, NULL, OPT_PAGE_OFFSET }, \
{ "port", 1, NULL, OPT_PORT }, \
+ { "port-lsr", 1, NULL, OPT_PORT_LSR }, \
+ { "port-lsr-val", 1, NULL, OPT_PORT_LSR_VAL }, \
{ "ramdisk", 1, NULL, OPT_INITRD }, \
{ "reuse-cmdline", 0, NULL, OPT_REUSE_CMDLINE }, \
@@ -34,6 +38,8 @@ static const char arm64_opts_usage[] __attribute__ ((unused)) =
" --lite Fast reboot, no memory integrity checks.\n"
" --page-offset Kernel page-offset for binary image load.\n"
" --port=ADDRESS Purgatory output to port ADDRESS.\n"
+" --port-lsr=ADDRESS Purgatory output port line status ADDRESS.\n"
+" --port-lsr-val=VALUE Purgatory output port Line status expected SET value when TX empty.\n"
" --ramdisk=FILE Use FILE as the kernel initial ramdisk.\n"
" --reuse-cmdline Use command line arg of primary kernel.\n";
@@ -43,6 +49,8 @@ struct arm64_opts {
const char *initrd;
uint64_t page_offset;
uint64_t port;
+ uint64_t port_lsr;
+ uint32_t port_lsr_val;
int lite;
};
diff --git a/kexec/arch/arm64/kexec-arm64.c b/kexec/arch/arm64/kexec-arm64.c
index 190037c75186..5c7445b86305 100644
--- a/kexec/arch/arm64/kexec-arm64.c
+++ b/kexec/arch/arm64/kexec-arm64.c
@@ -99,6 +99,12 @@ int arch_process_options(int argc, char **argv)
case OPT_PORT:
arm64_opts.port = strtoull(optarg, NULL, 0);
break;
+ case OPT_PORT_LSR:
+ arm64_opts.port_lsr = strtoull(optarg, NULL, 0);
+ break;
+ case OPT_PORT_LSR_VAL:
+ arm64_opts.port_lsr_val = strtoull(optarg, NULL, 0);
+ break;
case OPT_PAGE_OFFSET:
arm64_opts.page_offset = strtoull(optarg, NULL, 0);
break;
@@ -594,6 +600,8 @@ int arm64_load_other_segments(struct kexec_info *info,
unsigned long dtb_base;
char *initrd_buf = NULL;
uint64_t purgatory_sink;
+ uint64_t purgatory_sink_lsr;
+ uint32_t purgatory_sink_lsr_val;
unsigned long purgatory_base;
struct dtb dtb_1 = {.name = "dtb_1"};
struct dtb dtb_2 = {.name = "dtb_2"};
@@ -615,6 +623,9 @@ int arm64_load_other_segments(struct kexec_info *info,
dbgprintf("%s:%d: purgatory sink: 0x%" PRIx64 "\n", __func__, __LINE__,
purgatory_sink);
+ purgatory_sink_lsr = arm64_opts.port_lsr;
+ purgatory_sink_lsr_val = arm64_opts.port_lsr_val;
+
if (arm64_opts.dtb) {
dtb_2.buf = slurp_file(arm64_opts.dtb, &dtb_2.size);
assert(dtb_2.buf);
@@ -732,6 +743,12 @@ int arm64_load_other_segments(struct kexec_info *info,
elf_rel_set_symbol(&info->rhdr, "arm64_sink", &purgatory_sink,
sizeof(purgatory_sink));
+ elf_rel_set_symbol(&info->rhdr, "arm64_sink_lsr",
+ &purgatory_sink_lsr, sizeof(purgatory_sink_lsr));
+
+ elf_rel_set_symbol(&info->rhdr, "arm64_sink_lsr_val",
+ &purgatory_sink_lsr_val, sizeof(purgatory_sink_lsr_val));
+
elf_rel_set_symbol(&info->rhdr, "arm64_kernel_entry",
&kernel_entry, sizeof(kernel_entry));
diff --git a/purgatory/arch/arm64/entry.S b/purgatory/arch/arm64/entry.S
index 140e91d87ab1..fdb2fca774e7 100644
--- a/purgatory/arch/arm64/entry.S
+++ b/purgatory/arch/arm64/entry.S
@@ -43,6 +43,11 @@ arm64_sink:
.quad 0
size arm64_sink
+.globl arm64_sink_lsr
+arm64_sink_lsr:
+ .quad 0
+size arm64_sink_lsr
+
.globl arm64_kernel_entry
arm64_kernel_entry:
.quad 0
@@ -52,3 +57,8 @@ size arm64_kernel_entry
arm64_dtb_addr:
.quad 0
size arm64_dtb_addr
+
+.globl arm64_sink_lsr_val
+arm64_sink_lsr_val:
+ .word 0
+size arm64_sink_lsr_val
diff --git a/purgatory/arch/arm64/purgatory-arm64.c b/purgatory/arch/arm64/purgatory-arm64.c
index 25960c30bd05..1b88bb799f54 100644
--- a/purgatory/arch/arm64/purgatory-arm64.c
+++ b/purgatory/arch/arm64/purgatory-arm64.c
@@ -8,18 +8,38 @@
/* Symbols set by kexec. */
extern uint32_t *arm64_sink;
+extern uint32_t *arm64_sink_lsr;
+extern uint32_t arm64_sink_lsr_val;
extern void (*arm64_kernel_entry)(uint64_t);
extern uint64_t arm64_dtb_addr;
+static void wait_for_xmit_complete(void)
+{
+ volatile uint32_t status;
+ volatile uint32_t *status_reg = (volatile uint32_t *)arm64_sink_lsr;
+
+ if (!arm64_sink_lsr)
+ return;
+
+ while (1) {
+ status = *status_reg;
+ if ((status & arm64_sink_lsr_val) == arm64_sink_lsr_val)
+ break;
+ }
+}
+
void putchar(int ch)
{
if (!arm64_sink)
return;
+ wait_for_xmit_complete();
*arm64_sink = ch;
- if (ch == '\n')
+ if (ch == '\n') {
+ wait_for_xmit_complete();
*arm64_sink = '\r';
+ }
}
void setup_arch(void)
--
2.1.0
