The sclp console in the s390 bios writes raw data, leading console emulators (such as virsh console) to treat a new line ('\n') as just a new line instead of as a Unix line feed. Because of this, output appears in a "stair case" pattern.
Let's print \r\n on every occurrence of a new line in the string passed to write to amend this issue. This is in sync with the guest Linux code in drivers/s390/char/sclp_vt220.c which also does a line feed conversion in the console part of the driver. This fixes the s390-ccw and s390-netboot output like $ virsh start test --console Domain test started Connected to domain test Escape character is ^] Network boot starting... Using MAC address: 02:01:02:03:04:05 Requesting information via DHCP: 010 Signed-off-by: Collin L. Walling <wall...@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntrae...@de.ibm.com> --- pc-bios/s390-ccw/sclp.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/pc-bios/s390-ccw/sclp.c b/pc-bios/s390-ccw/sclp.c index 486fce1..f8ad5ae 100644 --- a/pc-bios/s390-ccw/sclp.c +++ b/pc-bios/s390-ccw/sclp.c @@ -68,17 +68,27 @@ void sclp_setup(void) long write(int fd, const void *str, size_t len) { WriteEventData *sccb = (void *)_sccb; + const char *p = str; + size_t data_len = 0; + size_t i; if (fd != 1 && fd != 2) { return -EIO; } - sccb->h.length = sizeof(WriteEventData) + len; + for (i = len; i > 0; i--) { + if (*p == '\n') { + sccb->data[data_len++] = '\r'; + } + sccb->data[data_len++] = *p; + p++; + } + + sccb->h.length = sizeof(WriteEventData) + data_len; sccb->h.function_code = SCLP_FC_NORMAL_WRITE; - sccb->ebh.length = sizeof(EventBufferHeader) + len; + sccb->ebh.length = sizeof(EventBufferHeader) + data_len; sccb->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA; sccb->ebh.flags = 0; - memcpy(sccb->data, str, len); sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb); -- 2.7.4