From e4d6c94e674a3162857dbd78c27b1d7a1b2c250f Mon Sep 17 00:00:00 2001
From: Roman Penyaev <r.peniaev@gmail.com>
Date: Wed, 26 Feb 2025 08:59:07 +0100
Subject: [PATCH] ui/console-vc: introduce parsing of the 'ESC ( <ch>' sequence
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This change introduces parsing of the 'ESC ( <ch>' sequence, which is
supposed to change character set [1]. In the QEMU case, the
introduced parsing logic does not actually change the character set, but
simply parses the sequence and does not let output of a tool to be
corrupted with leftovers: `top` sends 'ESC ( B', so if character
sequence is not parsed correctly, chracter 'B' appears in the output:
Btop - 11:08:42 up 5 min, 1 user, load average: 0BB
Tasks:B 158 Btotal,B 1 Brunning,B 157 Bsleeping,B 0 BsBB
%Cpu(s):B 0.0 Bus,B 0.0 Bsy,B 0.0 Bni,B 99.8 Bid,B 0.2 BB
MiB Mem :B 7955.6 Btotal,B 7778.6 Bfree,B 79.6 BB
MiB Swap:B 0.0 Btotal,B 0.0 Bfree,B 0.0 BB
PID USER PR NI VIRT RES SHR S B
B 735 root 20 0 9328 3540 3152 R B
B 1 root 20 0 20084 10904 8404 S B
B 2 root 20 0 0 0 0 S B
[1] https://vt100.net/docs/vt100-ug/chapter3.html#SCS
Signed-off-by: Roman Penyaev <r.peniaev@gmail.com>
Cc: "Marc-André Lureau" <marcandre.lureau@redhat.com>
Cc: qemu-devel@nongnu.org
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-ID: <20250226075913.353676-2-r.peniaev@gmail.com>
---
ui/console-vc.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/ui/console-vc.c b/ui/console-vc.c
index fe20579832..90ff0ffda8 100644
--- a/ui/console-vc.c
+++ b/ui/console-vc.c
@@ -42,6 +42,8 @@ enum TTYState {
TTY_STATE_NORM,
TTY_STATE_ESC,
TTY_STATE_CSI,
+ TTY_STATE_G0,
+ TTY_STATE_G1,
};
typedef struct QemuTextConsole {
@@ -694,6 +696,10 @@ static void vc_putchar(VCChardev *vc, int ch)
vc->esc_params[i] = 0;
vc->nb_esc_params = 0;
vc->state = TTY_STATE_CSI;
+ } else if (ch == '(') {
+ vc->state = TTY_STATE_G0;
+ } else if (ch == ')') {
+ vc->state = TTY_STATE_G1;
} else {
vc->state = TTY_STATE_NORM;
}
@@ -844,6 +850,16 @@ static void vc_putchar(VCChardev *vc, int ch)
}
break;
}
+ break;
+ case TTY_STATE_G0: /* set character sets */
+ case TTY_STATE_G1: /* set character sets */
+ switch (ch) {
+ case 'B':
+ /* Latin-1 map */
+ break;
+ }
+ vc->state = TTY_STATE_NORM;
+ break;
}
}
--
2.30.2