You can also limit the QR code size with DRM_PANIC_SCREEN_QR_VERSION.
Signed-off-by: Jocelyn Falempe <jfalempe@xxxxxxxxxx>
---
v2:
* Rewrite the rust comments with Markdown (Alice Ryhl)
* Mark drm_panic_qr_generate() as unsafe (Alice Ryhl)
* Use CStr directly, and remove the call to as_str_unchecked()
(Alice Ryhl)
* Add a check for data_len <= data_size (Greg KH)
v3:
* Fix all rust comments (typo, punctuation) (Miguel Ojeda)
* Change the wording of safety comments (Alice Ryhl)
* Add a link to the javascript decoder in the Kconfig (Greg KH)
* Fix data_size and tmp_size check in drm_panic_qr_generate()
v4:
* Fix the logic to find next line and skip the '\n' (Alic Ryhl)
* Remove __LOG_PREFIX as it's not used (Alice Ryhl)
drivers/gpu/drm/Kconfig | 31 +
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/drm_drv.c | 3 +
drivers/gpu/drm/drm_panic.c | 249 ++++++++
drivers/gpu/drm/drm_panic_qr.rs | 1003 +++++++++++++++++++++++++++++++
include/drm/drm_panic.h | 4 +
6 files changed, 1291 insertions(+)
create mode 100644 drivers/gpu/drm/drm_panic_qr.rs
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 6dd0016fc9cd..50ac967b56be 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -149,6 +149,37 @@ config DRM_PANIC_SCREEN
or by writing to /sys/module/drm/parameters/panic_screen sysfs entry
Default is "user"
+config DRM_PANIC_SCREEN_QR_CODE
+ bool "Add a panic screen with a QR code"
+ depends on DRM_PANIC && RUST
+ help
+ This option adds a QR code generator, and a panic screen with a QR
+ code. The QR code will contain the last lines of kmsg and other debug
+ information. This should be easier for the user to report a kernel
+ panic, with all debug information available.
+ To use this panic screen, also set DRM_PANIC_SCREEN to "qr_code"
+
+config DRM_PANIC_SCREEN_QR_CODE_URL
+ string "Base URL of the QR code in the panic screen"
+ depends on DRM_PANIC_SCREEN_QR_CODE
+ help
+ This option sets the base URL to report the kernel panic. If it's set
+ the QR code will contain the URL and the kmsg compressed with zlib as
+ a URL parameter. If it's empty, the QR code will contain the kmsg as
+ uncompressed text only.
+ There is a demo code in javascript, to decode and uncompress the kmsg
+ data from the URL parameter at https://github.com/kdj0c/panic_report
+
+config DRM_PANIC_SCREEN_QR_VERSION
+ int "Maximum version (size) of the QR code."
+ depends on DRM_PANIC_SCREEN_QR_CODE
+ default 40
+ help
+ This option limits the version (or size) of the QR code. QR code
+ version ranges from Version 1 (21x21) to Version 40 (177x177).
+ Smaller QR code are easier to read, but will contain less debugging
+ data. Default is 40.
+
config DRM_DEBUG_DP_MST_TOPOLOGY_REFS
bool "Enable refcount backtrace history in the DP MST helpers"
depends on STACKTRACE_SUPPORT
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 68cc9258ffc4..c62339b89d46 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -89,6 +89,7 @@ drm-$(CONFIG_DRM_PRIVACY_SCREEN) += \
drm_privacy_screen_x86.o
drm-$(CONFIG_DRM_ACCEL) += ../../accel/drm_accel.o
drm-$(CONFIG_DRM_PANIC) += drm_panic.o
+drm-$(CONFIG_DRM_PANIC_SCREEN_QR_CODE) += drm_panic_qr.o
obj-$(CONFIG_DRM) += drm.o
obj-$(CONFIG_DRM_PANEL_ORIENTATION_QUIRKS) += drm_panel_orientation_quirks.o
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 93543071a500..27007b53a8c8 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -1067,6 +1067,7 @@ static const struct file_operations drm_stub_fops = {
static void drm_core_exit(void)
{
drm_privacy_screen_lookup_exit();
+ drm_panic_exit();
accel_core_exit();
unregister_chrdev(DRM_MAJOR, "drm");
debugfs_remove(drm_debugfs_root);
@@ -1099,6 +1100,8 @@ static int __init drm_core_init(void)
if (ret < 0)
goto error;
+ drm_panic_init();
+
drm_privacy_screen_lookup_init();
drm_core_init_complete = true;
diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c
index 1fbefb99cf6e..1357d910b742 100644
--- a/drivers/gpu/drm/drm_panic.c
+++ b/drivers/gpu/drm/drm_panic.c
@@ -18,6 +18,8 @@
#include <linux/overflow.h>
#include <linux/printk.h>
#include <linux/types.h>
+#include <linux/utsname.h>
+#include <linux/zlib.h>
#include <drm/drm_drv.h>
#include <drm/drm_fourcc.h>
@@ -26,6 +28,7 @@
#include <drm/drm_panic.h>
#include <drm/drm_plane.h>
#include <drm/drm_print.h>
+#include <drm/drm_rect.h>
MODULE_AUTHOR("Jocelyn Falempe");
MODULE_DESCRIPTION("DRM panic handler");
@@ -621,6 +624,234 @@ static void draw_panic_static_kmsg(struct drm_scanout_buffer *sb)
}
}
+#if defined(CONFIG_DRM_PANIC_SCREEN_QR_CODE)
+/*
+ * It is unwise to allocate memory in the panic callback, so the buffers are
+ * pre-allocated. Only 2 buffers and the zlib workspace are needed.
+ * Two buffers are enough, using the following buffer usage:
+ * 1) kmsg messages are dumped in buffer1
+ * 2) kmsg is zlib-compressed into buffer2
+ * 3) compressed kmsg is encoded as QR-code Numeric stream in buffer1
+ * 4) QR-code image is generated in buffer2
+ * The Max QR code size is V40, 177x177, 4071 bytes for image, 2956 bytes for
+ * data segments.
+ *
+ * Typically, ~7500 bytes of kmsg, are compressed into 2800 bytes, which fits in
+ * a V40 QR-code (177x177).
+ *
+ * If CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL is not set, the kmsg data will be put
+ * directly in the QR code.
+ * 1) kmsg messages are dumped in buffer1
+ * 2) kmsg message is encoded as byte stream in buffer2
+ * 3) QR-code image is generated in buffer1
+ */
+
+static uint panic_qr_version = CONFIG_DRM_PANIC_SCREEN_QR_VERSION;
+module_param(panic_qr_version, uint, 0644);
+MODULE_PARM_DESC(panic_qr_version, "maximum version (size) of the QR code");
+
+#define MAX_QR_DATA 2956
+#define MAX_ZLIB_RATIO 3
+#define QR_BUFFER1_SIZE (MAX_ZLIB_RATIO * MAX_QR_DATA) /* Must also be > 4071 */
+#define QR_BUFFER2_SIZE 4096
+#define QR_MARGIN 4 /* 4 modules of foreground color around the qr code */
+
+/* Compression parameters */
+#define COMPR_LEVEL 6
+#define WINDOW_BITS 12
+#define MEM_LEVEL 4
+
+static char *qrbuf1;
+static char *qrbuf2;
+static struct z_stream_s stream;
+
+static void __init drm_panic_qr_init(void)
+{
+ qrbuf1 = kmalloc(QR_BUFFER1_SIZE, GFP_KERNEL);
+ qrbuf2 = kmalloc(QR_BUFFER2_SIZE, GFP_KERNEL);
+ stream.workspace = kmalloc(zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL),
+ GFP_KERNEL);
+}
+
+static void drm_panic_qr_exit(void)
+{
+ kfree(qrbuf1);
+ qrbuf1 = NULL;
+ kfree(qrbuf2);
+ qrbuf2 = NULL;
+ kfree(stream.workspace);
+ stream.workspace = NULL;
+}
+
+extern size_t drm_panic_qr_max_data_size(u8 version, size_t url_len);
+
+extern u8 drm_panic_qr_generate(const char *url, u8 *data, size_t data_len, size_t data_size,
+ u8 *tmp, size_t tmp_size);
+
+static int drm_panic_get_qr_code_url(u8 **qr_image)
+{
+ struct kmsg_dump_iter iter;
+ char url[256];
+ size_t kmsg_len, max_kmsg_size;
+ char *kmsg;
+ int max_qr_data_size, url_len;
+
+ url_len = snprintf(url, sizeof(url), CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL "?a=%s&v=%s&zl=",
+ utsname()->machine, utsname()->release);
+
+ max_qr_data_size = drm_panic_qr_max_data_size(panic_qr_version, url_len);
+ max_kmsg_size = min(MAX_ZLIB_RATIO * max_qr_data_size, QR_BUFFER1_SIZE);
+
+ /* get kmsg to buffer 1 */
+ kmsg_dump_rewind(&iter);
+ kmsg_dump_get_buffer(&iter, false, qrbuf1, max_kmsg_size, &kmsg_len);
+
+ if (!kmsg_len)
+ return -ENODATA;
+ kmsg = qrbuf1;
+
+try_again:
+ if (zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
+ MEM_LEVEL, Z_DEFAULT_STRATEGY) != Z_OK)
+ return -EINVAL;
+
+ stream.next_in = kmsg;
+ stream.avail_in = kmsg_len;
+ stream.total_in = 0;
+ stream.next_out = qrbuf2;
+ stream.avail_out = QR_BUFFER2_SIZE;
+ stream.total_out = 0;
+
+ if (zlib_deflate(&stream, Z_FINISH) != Z_STREAM_END)
+ return -EINVAL;
+
+ if (zlib_deflateEnd(&stream) != Z_OK)
+ return -EINVAL;
+
+ if (stream.total_out > max_qr_data_size) {
+ /* too much data for the QR code, so skip the first line and try again */
+ kmsg = strchr(kmsg, '\n');
+ if (!kmsg)
+ return -EINVAL;
+ /* skip the first \n */
+ kmsg += 1;
+ kmsg_len = strlen(kmsg);
+ goto try_again;
+ }
+ *qr_image = qrbuf2;
+
+ /* generate qr code image in buffer2 */
+ return drm_panic_qr_generate(url, qrbuf2, stream.total_out, QR_BUFFER2_SIZE,
+ qrbuf1, QR_BUFFER1_SIZE);
+}
+
+static int drm_panic_get_qr_code_raw(u8 **qr_image)
+{
+ struct kmsg_dump_iter iter;
+ size_t kmsg_len;
+ size_t max_kmsg_size = min(drm_panic_qr_max_data_size(panic_qr_version, 0),
+ QR_BUFFER1_SIZE);
+
+ kmsg_dump_rewind(&iter);
+ kmsg_dump_get_buffer(&iter, false, qrbuf1, max_kmsg_size, &kmsg_len);
+ if (!kmsg_len)
+ return -ENODATA;
+
+ *qr_image = qrbuf1;
+ return drm_panic_qr_generate(NULL, qrbuf1, kmsg_len, QR_BUFFER1_SIZE,
+ qrbuf2, QR_BUFFER2_SIZE);
+}
+
+static int drm_panic_get_qr_code(u8 **qr_image)
+{
+ if (strlen(CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL) > 0)
+ return drm_panic_get_qr_code_url(qr_image);
+ else
+ return drm_panic_get_qr_code_raw(qr_image);
+}
+
+/*
+ * Draw the panic message at the center of the screen, with a QR Code
+ */
+static int _draw_panic_static_qr_code(struct drm_scanout_buffer *sb)
+{
+ u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format);
+ u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format);
+ const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
+ struct drm_rect r_screen, r_logo, r_msg, r_qr, r_qr_canvas;
+ size_t max_qr_size, scale;
+ unsigned int panic_msg_width, qr_width, qr_canvas_width, v_margin;
+ u8 *qr_image;
+ unsigned int qr_pitch;
+
+ if (!font || !qrbuf1 || !qrbuf2 || !stream.workspace)
+ return -ENOMEM;
+
+ r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height);
+
+ drm_panic_logo_rect(&r_logo, font);
+
+ panic_msg_width = get_max_line_len(panic_msg, panic_msg_lines) * font->width;
+ r_msg = DRM_RECT_INIT(0, 0,
+ min(panic_msg_width, sb->width),
+ min(panic_msg_lines * font->height, sb->height));
+
+ max_qr_size = min(3 * sb->width / 4, 3 * sb->height / 4);
+
+ qr_width = drm_panic_get_qr_code(&qr_image);
+ if (qr_width <= 0)
+ return -ENOSPC;
+
+ qr_canvas_width = qr_width + QR_MARGIN * 2;
+ scale = max_qr_size / qr_canvas_width;
+ /* QR code is not readable if not scaled at least by 2 */
+ if (scale < 2)
+ return -ENOSPC;
+
+ pr_debug("QR width %d and scale %zu\n", qr_width, scale);
+ r_qr_canvas = DRM_RECT_INIT(0, 0, qr_canvas_width * scale, qr_canvas_width * scale);
+
+ v_margin = (sb->height - drm_rect_height(&r_qr_canvas) - drm_rect_height(&r_msg)) / 5;
+
+ drm_rect_translate(&r_qr_canvas, (sb->width - r_qr_canvas.x2) / 2, 2 * v_margin);
+ r_qr = DRM_RECT_INIT(r_qr_canvas.x1 + QR_MARGIN * scale, r_qr_canvas.y1 + QR_MARGIN * scale,
+ qr_width * scale, qr_width * scale);
+
+ /* Center the panic message */
+ drm_rect_translate(&r_msg, (sb->width - r_msg.x2) / 2,
+ 3 * v_margin + drm_rect_height(&r_qr_canvas));
+
+ /* Fill with the background color, and draw text on top */
+ drm_panic_fill(sb, &r_screen, bg_color);
+
+ if (!drm_rect_overlap(&r_logo, &r_msg) && !drm_rect_overlap(&r_logo, &r_qr))
+ drm_panic_logo_draw(sb, &r_logo, font, fg_color);
+
+ draw_txt_rectangle(sb, font, panic_msg, panic_msg_lines, true, &r_msg, fg_color);
+
+ /* Draw the qr code */
+ qr_pitch = DIV_ROUND_UP(qr_width, 8);
+ drm_panic_fill(sb, &r_qr_canvas, fg_color);
+ drm_panic_fill(sb, &r_qr, bg_color);
+ drm_panic_blit(sb, &r_qr, qr_image, qr_pitch, scale, fg_color);
+ return 0;
+}
+
+static void draw_panic_static_qr_code(struct drm_scanout_buffer *sb)
+{
+ if (_draw_panic_static_qr_code(sb))
+ draw_panic_static_user(sb);
+}
+#else
+static void draw_panic_static_qr_code(struct drm_scanout_buffer *sb)
+{
+ draw_panic_static_user(sb);
+}
+static void drm_panic_qr_init(void) {};
+static void drm_panic_qr_exit(void) {};
+#endif
+
+
/*
* drm_panic_is_format_supported()
* @format: a fourcc color code
@@ -639,6 +870,8 @@ static void draw_panic_dispatch(struct drm_scanout_buffer *sb)
{
if (!strcmp(drm_panic_screen, "kmsg")) {
draw_panic_static_kmsg(sb);
+ } else if (!strcmp(drm_panic_screen, "qr_code")) {
+ draw_panic_static_qr_code(sb);
} else {
draw_panic_static_user(sb);
}
@@ -763,3 +996,19 @@ void drm_panic_unregister(struct drm_device *dev)
}
}
EXPORT_SYMBOL(drm_panic_unregister);
+
+/**
+ * drm_panic_init() - initialize DRM panic.
+ */
+void __init drm_panic_init(void)
+{
+ drm_panic_qr_init();
+}
+
+/**
+ * drm_panic_exit() - Free the resources taken by drm_panic_exit()
+ */
+void drm_panic_exit(void)
+{
+ drm_panic_qr_exit();
+}
diff --git a/drivers/gpu/drm/drm_panic_qr.rs b/drivers/gpu/drm/drm_panic_qr.rs
new file mode 100644
index 000000000000..1ef56cb07dfb
--- /dev/null
+++ b/drivers/gpu/drm/drm_panic_qr.rs
@@ -0,0 +1,1003 @@
+// SPDX-License-Identifier: MIT
+
+//! This is a simple QR encoder for DRM panic.
+//!
+//! It is called from a panic handler, so it should't allocate memory and
+//! does all the work on the stack or on the provided buffers. For
+//! simplification, it only supports low error correction, and applies the
+//! first mask (checkerboard). It will draw the smallest QRcode that can
+//! contain the string passed as parameter. To get the most compact
+//! QR code, the start of the URL is encoded as binary, and the
+//! compressed kmsg is encoded as numeric.
+//!
+//! The binary data must be a valid URL parameter, so the easiest way is
+//! to use base64 encoding. But this wastes 25% of data space, so the
+//! whole stack trace won't fit in the QR code. So instead it encodes
+//! every 13bits of input into 4 decimal digits, and then uses the
+//! efficient numeric encoding, that encode 3 decimal digits into
+//! 10bits. This makes 39bits of compressed data into 12 decimal digits,
+//! into 40bits in the QR code, so wasting only 2.5%. And the numbers are
+//! valid URL parameter, so the website can do the reverse, to get the
+//! binary data.
+//!
+//! Inspired by these 3 projects, all under MIT license:
+//!
+//! * <https://github.com/kennytm/qrcode-rust>
+//! * <https://github.com/erwanvivien/fast_qr>
+//! * <https://github.com/bjguillot/qr>
+
+use core::cmp;
+use kernel::str::CStr;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Ord, PartialOrd)]
+struct Version(usize);
+
+// Generator polynomials for ECC, only those that are needed for low quality.
+const P7: [u8; 7] = [87, 229, 146, 149, 238, 102, 21];
+const P10: [u8; 10] = [251, 67, 46, 61, 118, 70, 64, 94, 32, 45];
+const P15: [u8; 15] = [
+ 8, 183, 61, 91, 202, 37, 51, 58, 58, 237, 140, 124, 5, 99, 105,
+];
+const P18: [u8; 18] = [
+ 215, 234, 158, 94, 184, 97, 118, 170, 79, 187, 152, 148, 252, 179, 5, 98, 96, 153,
+];
+const P20: [u8; 20] = [
+ 17, 60, 79, 50, 61, 163, 26, 187, 202, 180, 221, 225, 83, 239, 156, 164, 212, 212, 188, 190,
+];
+const P22: [u8; 22] = [
+ 210, 171, 247, 242, 93, 230, 14, 109, 221, 53, 200, 74, 8, 172, 98, 80, 219, 134, 160, 105,
+ 165, 231,
+];
+const P24: [u8; 24] = [
+ 229, 121, 135, 48, 211, 117, 251, 126, 159, 180, 169, 152, 192, 226, 228, 218, 111, 0, 117,
+ 232, 87, 96, 227, 21,
+];
+const P26: [u8; 26] = [
+ 173, 125, 158, 2, 103, 182, 118, 17, 145, 201, 111, 28, 165, 53, 161, 21, 245, 142, 13, 102,
+ 48, 227, 153, 145, 218, 70,
+];
+const P28: [u8; 28] = [
+ 168, 223, 200, 104, 224, 234, 108, 180, 110, 190, 195, 147, 205, 27, 232, 201, 21, 43, 245, 87,
+ 42, 195, 212, 119, 242, 37, 9, 123,
+];
+const P30: [u8; 30] = [
+ 41, 173, 145, 152, 216, 31, 179, 182, 50, 48, 110, 86, 239, 96, 222, 125, 42, 173, 226, 193,
+ 224, 130, 156, 37, 251, 216, 238, 40, 192, 180,
+];
+
+/// QR Code parameters for Low quality ECC:
+/// - Error Correction polynomial.
+/// - Number of blocks in group 1.
+/// - Number of blocks in group 2.
+/// - Block size in group 1.
+///
+/// (Block size in group 2 is one more than group 1).
+struct VersionParameter(&'static [u8], u8, u8, u8);
+const VPARAM: [VersionParameter; 40] = [
+ VersionParameter(&P7, 1, 0, 19), // V1
+ VersionParameter(&P10, 1, 0, 34), // V2
+ VersionParameter(&P15, 1, 0, 55), // V3
+ VersionParameter(&P20, 1, 0, 80), // V4
+ VersionParameter(&P26, 1, 0, 108), // V5
+ VersionParameter(&P18, 2, 0, 68), // V6
+ VersionParameter(&P20, 2, 0, 78), // V7
+ VersionParameter(&P24, 2, 0, 97), // V8
+ VersionParameter(&P30, 2, 0, 116), // V9
+ VersionParameter(&P18, 2, 2, 68), // V10
+ VersionParameter(&P20, 4, 0, 81), // V11
+ VersionParameter(&P24, 2, 2, 92), // V12
+ VersionParameter(&P26, 4, 0, 107), // V13
+ VersionParameter(&P30, 3, 1, 115), // V14
+ VersionParameter(&P22, 5, 1, 87), // V15
+ VersionParameter(&P24, 5, 1, 98), // V16
+ VersionParameter(&P28, 1, 5, 107), // V17
+ VersionParameter(&P30, 5, 1, 120), // V18
+ VersionParameter(&P28, 3, 4, 113), // V19
+ VersionParameter(&P28, 3, 5, 107), // V20
+ VersionParameter(&P28, 4, 4, 116), // V21
+ VersionParameter(&P28, 2, 7, 111), // V22
+ VersionParameter(&P30, 4, 5, 121), // V23
+ VersionParameter(&P30, 6, 4, 117), // V24
+ VersionParameter(&P26, 8, 4, 106), // V25
+ VersionParameter(&P28, 10, 2, 114), // V26
+ VersionParameter(&P30, 8, 4, 122), // V27
+ VersionParameter(&P30, 3, 10, 117), // V28
+ VersionParameter(&P30, 7, 7, 116), // V29
+ VersionParameter(&P30, 5, 10, 115), // V30
+ VersionParameter(&P30, 13, 3, 115), // V31
+ VersionParameter(&P30, 17, 0, 115), // V32
+ VersionParameter(&P30, 17, 1, 115), // V33
+ VersionParameter(&P30, 13, 6, 115), // V34
+ VersionParameter(&P30, 12, 7, 121), // V35
+ VersionParameter(&P30, 6, 14, 121), // V36
+ VersionParameter(&P30, 17, 4, 122), // V37
+ VersionParameter(&P30, 4, 18, 122), // V38
+ VersionParameter(&P30, 20, 4, 117), // V39
+ VersionParameter(&P30, 19, 6, 118), // V40
+];
+
+const MAX_EC_SIZE: usize = 30;
+const MAX_BLK_SIZE: usize = 123;
+
+/// Position of the alignment pattern grid.
+const ALIGNMENT_PATTERNS: [&[u8]; 40] = [
+ &[],
+ &[6, 18],
+ &[6, 22],
+ &[6, 26],
+ &[6, 30],
+ &[6, 34],
+ &[6, 22, 38],
+ &[6, 24, 42],
+ &[6, 26, 46],
+ &[6, 28, 50],
+ &[6, 30, 54],
+ &[6, 32, 58],
+ &[6, 34, 62],
+ &[6, 26, 46, 66],
+ &[6, 26, 48, 70],
+ &[6, 26, 50, 74],
+ &[6, 30, 54, 78],
+ &[6, 30, 56, 82],
+ &[6, 30, 58, 86],
+ &[6, 34, 62, 90],
+ &[6, 28, 50, 72, 94],
+ &[6, 26, 50, 74, 98],
+ &[6, 30, 54, 78, 102],
+ &[6, 28, 54, 80, 106],
+ &[6, 32, 58, 84, 110],
+ &[6, 30, 58, 86, 114],
+ &[6, 34, 62, 90, 118],
+ &[6, 26, 50, 74, 98, 122],
+ &[6, 30, 54, 78, 102, 126],
+ &[6, 26, 52, 78, 104, 130],
+ &[6, 30, 56, 82, 108, 134],
+ &[6, 34, 60, 86, 112, 138],
+ &[6, 30, 58, 86, 114, 142],
+ &[6, 34, 62, 90, 118, 146],
+ &[6, 30, 54, 78, 102, 126, 150],
+ &[6, 24, 50, 76, 102, 128, 154],
+ &[6, 28, 54, 80, 106, 132, 158],
+ &[6, 32, 58, 84, 110, 136, 162],
+ &[6, 26, 54, 82, 110, 138, 166],
+ &[6, 30, 58, 86, 114, 142, 170],
+];
+
+/// Version information for format V7-V40.
+const VERSION_INFORMATION: [u32; 34] = [
+ 0b00_0111_1100_1001_0100,
+ 0b00_1000_0101_1011_1100,
+ 0b00_1001_1010_1001_1001,
+ 0b00_1010_0100_1101_0011,
+ 0b00_1011_1011_1111_0110,
+ 0b00_1100_0111_0110_0010,
+ 0b00_1101_1000_0100_0111,
+ 0b00_1110_0110_0000_1101,
+ 0b00_1111_1001_0010_1000,
+ 0b01_0000_1011_0111_1000,
+ 0b01_0001_0100_0101_1101,
+ 0b01_0010_1010_0001_0111,
+ 0b01_0011_0101_0011_0010,
+ 0b01_0100_1001_1010_0110,
+ 0b01_0101_0110_1000_0011,
+ 0b01_0110_1000_1100_1001,
+ 0b01_0111_0111_1110_1100,
+ 0b01_1000_1110_1100_0100,
+ 0b01_1001_0001_1110_0001,
+ 0b01_1010_1111_1010_1011,
+ 0b01_1011_0000_1000_1110,
+ 0b01_1100_1100_0001_1010,
+ 0b01_1101_0011_0011_1111,
+ 0b01_1110_1101_0111_0101,
+ 0b01_1111_0010_0101_0000,
+ 0b10_0000_1001_1101_0101,
+ 0b10_0001_0110_1111_0000,
+ 0b10_0010_1000_1011_1010,
+ 0b10_0011_0111_1001_1111,
+ 0b10_0100_1011_0000_1011,
+ 0b10_0101_0100_0010_1110,
+ 0b10_0110_1010_0110_0100,
+ 0b10_0111_0101_0100_0001,
+ 0b10_1000_1100_0110_1001,
+];
+
+/// Format info for low quality ECC.
+const FORMAT_INFOS_QR_L: [u16; 8] = [
+ 0x77c4, 0x72f3, 0x7daa, 0x789d, 0x662f, 0x6318, 0x6c41, 0x6976,
+];
+
+impl Version {
+ /// Returns the smallest QR version than can hold these segments.
+ fn from_segments(segments: &[&Segment<'_>]) -> Option<Version> {
+ for v in (1..=40).map(|k| Version(k)) {
+ if v.max_data() * 8 >= segments.iter().map(|s| s.total_size_bits(v)).sum() {
+ return Some(v);
+ }
+ }
+ None
+ }
+
+ fn width(&self) -> u8 {
+ (self.0 as u8) * 4 + 17
+ }
+
+ fn max_data(&self) -> usize {
+ self.g1_blk_size() * self.g1_blocks() + (self.g1_blk_size() + 1) * self.g2_blocks()
+ }
+
+ fn ec_size(&self) -> usize {
+ VPARAM[self.0 - 1].0.len()
+ }
+
+ fn g1_blocks(&self) -> usize {
+ VPARAM[self.0 - 1].1 as usize
+ }
+
+ fn g2_blocks(&self) -> usize {
+ VPARAM[self.0 - 1].2 as usize
+ }
+
+ fn g1_blk_size(&self) -> usize {
+ VPARAM[self.0 - 1].3 as usize
+ }
+
+ fn alignment_pattern(&self) -> &'static [u8] {
+ &ALIGNMENT_PATTERNS[self.0 - 1]
+ }
+
+ fn poly(&self) -> &'static [u8] {
+ VPARAM[self.0 - 1].0
+ }
+
+ fn version_info(&self) -> u32 {
+ if *self >= Version(7) {
+ VERSION_INFORMATION[self.0 - 7]
+ } else {
+ 0
+ }
+ }
+}
+
+/// Exponential table for Galois Field GF(256).
+const EXP_TABLE: [u8; 256] = [
+ 1, 2, 4, 8, 16, 32, 64, 128, 29, 58, 116, 232, 205, 135, 19, 38, 76, 152, 45, 90, 180, 117,
+ 234, 201, 143, 3, 6, 12, 24, 48, 96, 192, 157, 39, 78, 156, 37, 74, 148, 53, 106, 212, 181,
+ 119, 238, 193, 159, 35, 70, 140, 5, 10, 20, 40, 80, 160, 93, 186, 105, 210, 185, 111, 222, 161,
+ 95, 190, 97, 194, 153, 47, 94, 188, 101, 202, 137, 15, 30, 60, 120, 240, 253, 231, 211, 187,
+ 107, 214, 177, 127, 254, 225, 223, 163, 91, 182, 113, 226, 217, 175, 67, 134, 17, 34, 68, 136,
+ 13, 26, 52, 104, 208, 189, 103, 206, 129, 31, 62, 124, 248, 237, 199, 147, 59, 118, 236, 197,
+ 151, 51, 102, 204, 133, 23, 46, 92, 184, 109, 218, 169, 79, 158, 33, 66, 132, 21, 42, 84, 168,
+ 77, 154, 41, 82, 164, 85, 170, 73, 146, 57, 114, 228, 213, 183, 115, 230, 209, 191, 99, 198,
+ 145, 63, 126, 252, 229, 215, 179, 123, 246, 241, 255, 227, 219, 171, 75, 150, 49, 98, 196, 149,
+ 55, 110, 220, 165, 87, 174, 65, 130, 25, 50, 100, 200, 141, 7, 14, 28, 56, 112, 224, 221, 167,
+ 83, 166, 81, 162, 89, 178, 121, 242, 249, 239, 195, 155, 43, 86, 172, 69, 138, 9, 18, 36, 72,
+ 144, 61, 122, 244, 245, 247, 243, 251, 235, 203, 139, 11, 22, 44, 88, 176, 125, 250, 233, 207,
+ 131, 27, 54, 108, 216, 173, 71, 142, 1,
+];
+
+/// Reverse exponential table for Galois Field GF(256).
+const LOG_TABLE: [u8; 256] = [
+ 175, 0, 1, 25, 2, 50, 26, 198, 3, 223, 51, 238, 27, 104, 199, 75, 4, 100, 224, 14, 52, 141,
+ 239, 129, 28, 193, 105, 248, 200, 8, 76, 113, 5, 138, 101, 47, 225, 36, 15, 33, 53, 147, 142,
+ 218, 240, 18, 130, 69, 29, 181, 194, 125, 106, 39, 249, 185, 201, 154, 9, 120, 77, 228, 114,
+ 166, 6, 191, 139, 98, 102, 221, 48, 253, 226, 152, 37, 179, 16, 145, 34, 136, 54, 208, 148,
+ 206, 143, 150, 219, 189, 241, 210, 19, 92, 131, 56, 70, 64, 30, 66, 182, 163, 195, 72, 126,
+ 110, 107, 58, 40, 84, 250, 133, 186, 61, 202, 94, 155, 159, 10, 21, 121, 43, 78, 212, 229, 172,
+ 115, 243, 167, 87, 7, 112, 192, 247, 140, 128, 99, 13, 103, 74, 222, 237, 49, 197, 254, 24,
+ 227, 165, 153, 119, 38, 184, 180, 124, 17, 68, 146, 217, 35, 32, 137, 46, 55, 63, 209, 91, 149,
+ 188, 207, 205, 144, 135, 151, 178, 220, 252, 190, 97, 242, 86, 211, 171, 20, 42, 93, 158, 132,
+ 60, 57, 83, 71, 109, 65, 162, 31, 45, 67, 216, 183, 123, 164, 118, 196, 23, 73, 236, 127, 12,
+ 111, 246, 108, 161, 59, 82, 41, 157, 85, 170, 251, 96, 134, 177, 187, 204, 62, 90, 203, 89, 95,
+ 176, 156, 169, 160, 81, 11, 245, 22, 235, 122, 117, 44, 215, 79, 174, 213, 233, 230, 231, 173,
+ 232, 116, 214, 244, 234, 168, 80, 88, 175,
+];
+
+// 4 bits segment header.
+const MODE_STOP: u16 = 0;
+const MODE_NUMERIC: u16 = 1;
+const MODE_BINARY: u16 = 4;
+/// Padding bytes.
+const PADDING: [u8; 2] = [236, 17];
+
+/// Get the next 13 bits of data, starting at specified offset (in bits).
+fn get_next_13b(data: &[u8], offset: usize) -> Option<(u16, usize)> {
+ if offset < data.len() * 8 {
+ let size = cmp::min(13, data.len() * 8 - offset);
+ let byte_off = offset / 8;
+ let bit_off = offset % 8;
+ // `b` is 20 at max (`bit_off` <= 7 and `size` <= 13).
+ let b = (bit_off + size) as u16;
+
+ let first_byte = (data[byte_off] << bit_off >> bit_off) as u16;
+
+ let number = match b {
+ 0..=8 => first_byte >> (8 - b),
+ 9..=16 => (first_byte << (b - 8)) + (data[byte_off + 1] >> (16 - b)) as u16,
+ _ => {
+ (first_byte << (b - 8))
+ + ((data[byte_off + 1] as u16) << (b - 16))
+ + (data[byte_off + 2] >> (24 - b)) as u16
+ }
+ };
+ Some((number, size))
+ } else {
+ None
+ }
+}
+
+/// Number of bits to encode characters in numeric mode.
+const NUM_CHARS_BITS: [usize; 4] = [0, 4, 7, 10];
+const POW10: [u16; 4] = [1, 10, 100, 1000];
+
+enum Segment<'a> {
+ Numeric(&'a [u8]),
+ Binary(&'a [u8]),
+}
+
+impl Segment<'_> {
+ fn get_header(&self) -> (u16, usize) {
+ match self {
+ Segment::Binary(_) => (MODE_BINARY, 4),
+ Segment::Numeric(_) => (MODE_NUMERIC, 4),
+ }
+ }
+
+ // Returns the size of the length field in bits, depending on QR Version.
+ fn length_bits_count(&self, version: Version) -> usize {
+ let Version(v) = version;
+ match self {
+ Segment::Binary(_) => match v {
+ 1..=9 => 8,
+ _ => 16,
+ },
+ Segment::Numeric(_) => match v {
+ 1..=9 => 10,
+ 10..=26 => 12,
+ _ => 14,
+ },
+ }
+ }
+
+ // Number of characters in the segment.
+ fn character_count(&self) -> usize {
+ match self {
+ Segment::Binary(data) => data.len(),
+ Segment::Numeric(data) => {
+ let data_bits = data.len() * 8;
+ let last_chars = match data_bits % 13 {
+ 1 => 1,
+ k => (k + 1) / 3,
+ };
+ // 4 decimal numbers per 13bits + remainder.
+ 4 * (data_bits / 13) + last_chars
+ }
+ }
+ }
+
+ fn get_length_field(&self, version: Version) -> (u16, usize) {
+ (
+ self.character_count() as u16,
+ self.length_bits_count(version),
+ )
+ }
+
+ fn total_size_bits(&self, version: Version) -> usize {
+ let data_size = match self {
+ Segment::Binary(data) => data.len() * 8,
+ Segment::Numeric(_) => {
+ let digits = self.character_count();
+ 10 * (digits / 3) + NUM_CHARS_BITS[digits % 3]
+ }
+ };
+ // header + length + data.
+ 4 + self.length_bits_count(version) + data_size
+ }
+
+ fn iter(&self) -> SegmentIterator<'_> {
+ SegmentIterator {
+ segment: self,
+ offset: 0,
+ carry: 0,
+ carry_len: 0,
+ }
+ }
+}
+
+struct SegmentIterator<'a> {
+ segment: &'a Segment<'a>,
+ offset: usize,
+ carry: u16,
+ carry_len: usize,
+}
+
+impl Iterator for SegmentIterator<'_> {
+ type Item = (u16, usize);
+
+ fn next(&mut self) -> Option<Self::Item> {
+ match self.segment {
+ Segment::Binary(data) => {
+ if self.offset < data.len() {
+ let byte = data[self.offset] as u16;
+ self.offset += 1;
+ Some((byte, 8))
+ } else {
+ None
+ }
+ }
+ Segment::Numeric(data) => {
+ if self.carry_len == 3 {
+ let out = (self.carry, NUM_CHARS_BITS[self.carry_len]);
+ self.carry_len = 0;
+ self.carry = 0;
+ Some(out)
+ } else if let Some((bits, size)) = get_next_13b(data, self.offset) {
+ self.offset += size;
+ let new_chars = match size {
+ 1 => 1,
+ k => (k + 1) / 3,
+ };
+ if self.carry_len + new_chars > 3 {
+ self.carry_len = new_chars + self.carry_len - 3;
+ let out = (
+ self.carry * POW10[new_chars - self.carry_len]
+ + bits / POW10[self.carry_len],
+ NUM_CHARS_BITS[3],
+ );
+ self.carry = bits % POW10[self.carry_len];
+ Some(out)
+ } else {
+ let out = (
+ self.carry * POW10[new_chars] + bits,
+ NUM_CHARS_BITS[self.carry_len + new_chars],
+ );
+ self.carry_len = 0;
+ Some(out)
+ }
+ } else if self.carry_len > 0 {
+ let out = (self.carry, NUM_CHARS_BITS[self.carry_len]);
+ self.carry_len = 0;
+ Some(out)
+ } else {
+ None
+ }
+ }
+ }
+ }
+}
+
+struct EncodedMsg<'a> {
+ data: &'a mut [u8],
+ ec_size: usize,
+ g1_blocks: usize,
+ g2_blocks: usize,
+ g1_blk_size: usize,
+ g2_blk_size: usize,
+ poly: &'static [u8],
+ version: Version,
+}
+
+/// Data to be put in the QR code, with correct segment encoding, padding, and
+/// Error Code Correction.
+impl EncodedMsg<'_> {
+ fn new<'a, 'b>(segments: &[&Segment<'b>], data: &'a mut [u8]) -> Option<EncodedMsg<'a>> {
+ let version = Version::from_segments(segments)?;
+ let ec_size = version.ec_size();
+ let g1_blocks = version.g1_blocks();
+ let g2_blocks = version.g2_blocks();
+ let g1_blk_size = version.g1_blk_size();
+ let g2_blk_size = g1_blk_size + 1;
+ let poly = version.poly();
+
+ // clear the output.
+ data.fill(0);
+
+ let mut em = EncodedMsg {
+ data: data,
+ ec_size,
+ g1_blocks,
+ g2_blocks,
+ g1_blk_size,
+ g2_blk_size,
+ poly,
+ version,
+ };
+ em.encode(segments);
+ Some(em)
+ }
+
+ /// Push bits of data at an offset (in bits).
+ fn push(&mut self, offset: &mut usize, bits: (u16, usize)) {
+ let (number, len_bits) = bits;
+ let byte_off = *offset / 8;
+ let bit_off = *offset % 8;
+ let b = bit_off + len_bits;
+
+ match (bit_off, b) {
+ (0, 0..=8) => {
+ self.data[byte_off] = (number << (8 - b)) as u8;
+ }
+ (0, _) => {
+ self.data[byte_off] = (number >> (b - 8)) as u8;
+ self.data[byte_off + 1] = (number << (16 - b)) as u8;
+ }
+ (_, 0..=8) => {
+ self.data[byte_off] |= (number << (8 - b)) as u8;
+ }
+ (_, 9..=16) => {
+ self.data[byte_off] |= (number >> (b - 8)) as u8;
+ self.data[byte_off + 1] = (number << (16 - b)) as u8;
+ }
+ _ => {
+ self.data[byte_off] |= (number >> (b - 8)) as u8;
+ self.data[byte_off + 1] = (number >> (b - 16)) as u8;
+ self.data[byte_off + 2] = (number << (24 - b)) as u8;
+ }
+ }
+ *offset += len_bits;
+ }
+
+ fn add_segments(&mut self, segments: &[&Segment<'_>]) {
+ let mut offset: usize = 0;
+
+ for s in segments.iter() {
+ self.push(&mut offset, s.get_header());
+ self.push(&mut offset, s.get_length_field(self.version));
+ for bits in s.iter() {
+ self.push(&mut offset, bits);
+ }
+ }
+ self.push(&mut offset, (MODE_STOP, 4));
+
+ let pad_offset = (offset + 7) / 8;
+ for i in pad_offset..self.version.max_data() {
+ self.data[i] = PADDING[(i & 1) ^ (pad_offset & 1)];
+ }
+ }
+
+ fn error_code_for_blocks(&mut self, offset: usize, size: usize, ec_offset: usize) {
+ let mut tmp: [u8; MAX_BLK_SIZE + MAX_EC_SIZE] = [0; MAX_BLK_SIZE + MAX_EC_SIZE];
+
+ tmp[0..size].copy_from_slice(&self.data[offset..offset + size]);
+ for i in 0..size {
+ let lead_coeff = tmp[i] as usize;
+ if lead_coeff == 0 {
+ continue;
+ }
+ let log_lead_coeff = usize::from(LOG_TABLE[lead_coeff]);
+ for (u, &v) in tmp[i + 1..].iter_mut().zip(self.poly.iter()) {
+ *u ^= EXP_TABLE[(usize::from(v) + log_lead_coeff) % 255];
+ }
+ }
+ self.data[ec_offset..ec_offset + self.ec_size]
+ .copy_from_slice(&tmp[size..size + self.ec_size]);
+ }
+
+ fn compute_error_code(&mut self) {
+ let mut offset = 0;
+ let mut ec_offset = self.g1_blocks * self.g1_blk_size + self.g2_blocks * self.g2_blk_size;
+
+ for _ in 0..self.g1_blocks {
+ self.error_code_for_blocks(offset, self.g1_blk_size, ec_offset);
+ offset += self.g1_blk_size;
+ ec_offset += self.ec_size;
+ }
+ for _ in 0..self.g2_blocks {
+ self.error_code_for_blocks(offset, self.g2_blk_size, ec_offset);
+ offset += self.g2_blk_size;
+ ec_offset += self.ec_size;
+ }
+ }
+
+ fn encode(&mut self, segments: &[&Segment<'_>]) {
+ self.add_segments(segments);
+ self.compute_error_code();
+ }
+
+ fn iter(&self) -> EncodedMsgIterator<'_> {
+ EncodedMsgIterator {
+ em: self,
+ offset: 0,
+ }
+ }
+}
+
+/// Iterator, to retrieve the data in the interleaved order needed by QR code.
+struct EncodedMsgIterator<'a> {
+ em: &'a EncodedMsg<'a>,
+ offset: usize,
+}
+
+impl Iterator for EncodedMsgIterator<'_> {
+ type Item = u8;
+
+ // Send the bytes in interleaved mode, first byte of first block of group1,
+ // then first byte of second block of group1, ...
+ fn next(&mut self) -> Option<Self::Item> {
+ let em = self.em;
+ let blocks = em.g1_blocks + em.g2_blocks;
+ let g1_end = em.g1_blocks * em.g1_blk_size;
+ let g2_end = g1_end + em.g2_blocks * em.g2_blk_size;
+ let ec_end = g2_end + em.ec_size * blocks;
+
+ if self.offset >= ec_end {
+ return None;
+ }
+
+ let offset = if self.offset < em.g1_blk_size * blocks {
+ // group1 and group2 interleaved
+ let blk = self.offset % blocks;
+ let blk_off = self.offset / blocks;
+ if blk < em.g1_blocks {
+ blk * em.g1_blk_size + blk_off
+ } else {
+ g1_end + em.g2_blk_size * (blk - em.g1_blocks) + blk_off
+ }
+ } else if self.offset < g2_end {
+ // last byte of group2 blocks
+ let blk2 = self.offset - blocks * em.g1_blk_size;
+ em.g1_blk_size * em.g1_blocks + blk2 * em.g2_blk_size + em.g2_blk_size - 1
+ } else {
+ // EC blocks
+ let ec_offset = self.offset - g2_end;
+ let blk = ec_offset % blocks;
+ let blk_off = ec_offset / blocks;
+
+ g2_end + blk * em.ec_size + blk_off
+ };
+ self.offset += 1;
+ Some(em.data[offset])
+ }
+}
+
+/// A QR code image, encoded as a linear binary framebuffer.
+/// 1 bit per module (pixel), each new line start at next byte boundary.
+/// Max width is 177 for V40 QR code, so `u8` is enough for coordinate.
+struct QrImage<'a> {
+ data: &'a mut [u8],
+ width: u8,
+ stride: u8,
+ version: Version,
+}
+
+impl QrImage<'_> {
+ fn new<'a, 'b>(em: &'b EncodedMsg<'b>, qrdata: &'a mut [u8]) -> QrImage<'a> {
+ let width = em.version.width();
+ let stride = (width + 7) / 8;
+ let data = qrdata;
+
+ let mut qr_image = QrImage {
+ data,
+ width,
+ stride,
+ version: em.version,
+ };
+ qr_image.draw_all(em.iter());
+ qr_image
+ }
+
+ fn clear(&mut self) {
+ self.data.fill(0);
+ }
+
+ // Set pixel to light color.
+ fn set(&mut self, x: u8, y: u8) {
+ let off = y as usize * self.stride as usize + x as usize / 8;
+ let mut v = self.data[off];
+ v |= 0x80 >> (x % 8);
+ self.data[off] = v;
+ }
+
+ // Invert a module color.
+ fn xor(&mut self, x: u8, y: u8) {
+ let off = y as usize * self.stride as usize + x as usize / 8;
+ self.data[off] ^= 0x80 >> (x % 8);
+ }
+
+ // Draw a light square at (x, y) top left corner.
+ fn draw_square(&mut self, x: u8, y: u8, size: u8) {
+ for k in 0..size {
+ self.set(x + k, y);
+ self.set(x, y + k + 1);
+ self.set(x + size, y + k);
+ self.set(x + k + 1, y + size);
+ }
+ }
+
+ // Finder pattern: 3 8x8 square at the corners.
+ fn draw_finders(&mut self) {
+ self.draw_square(1, 1, 4);
+ self.draw_square(self.width - 6, 1, 4);
+ self.draw_square(1, self.width - 6, 4);
+ for k in 0..8 {
+ self.set(k, 7);
+ self.set(self.width - k - 1, 7);
+ self.set(k, self.width - 8);
+ }
+ for k in 0..7 {
+ self.set(7, k);
+ self.set(self.width - 8, k);
+ self.set(7, self.width - 1 - k);
+ }
+ }
+
+ fn is_finder(&self, x: u8, y: u8) -> bool {
+ let end = self.width - 8;
+ (x < 8 && y < 8) || (x < 8 && y >= end) || (x >= end && y < 8)
+ }
+
+ // Alignment pattern: 5x5 squares in a grid.
+ fn draw_alignments(&mut self) {
+ let positions = self.version.alignment_pattern();
+ for &x in positions.iter() {
+ for &y in positions.iter() {
+ if !self.is_finder(x, y) {
+ self.draw_square(x - 1, y - 1, 2);
+ }
+ }
+ }
+ }
+
+ fn is_alignment(&self, x: u8, y: u8) -> bool {
+ let positions = self.version.alignment_pattern();
+ for &ax in positions.iter() {
+ for &ay in positions.iter() {
+ if self.is_finder(ax, ay) {
+ continue;
+ }
+ if x >= ax - 2 && x <= ax + 2 && y >= ay - 2 && y <= ay + 2 {
+ return true;
+ }
+ }
+ }
+ false
+ }
+
+ // Timing pattern: 2 dotted line between the finder patterns.
+ fn draw_timing_patterns(&mut self) {
+ let end = self.width - 8;
+
+ for x in (9..end).step_by(2) {
+ self.set(x, 6);
+ self.set(6, x);
+ }
+ }
+
+ fn is_timing(&self, x: u8, y: u8) -> bool {
+ x == 6 || y == 6
+ }
+
+ // Mask info: 15 bits around the finders, written twice for redundancy.
+ fn draw_maskinfo(&mut self) {
+ let info: u16 = FORMAT_INFOS_QR_L[0];
+ let mut skip = 0;
+
+ for k in 0..7 {
+ if k == 6 {
+ skip = 1;
+ }
+ if info & (1 << (14 - k)) == 0 {
+ self.set(k + skip, 8);
+ self.set(8, self.width - 1 - k);
+ }
+ }
+ skip = 0;
+ for k in 0..8 {
+ if k == 2 {
+ skip = 1;
+ }
+ if info & (1 << (7 - k)) == 0 {
+ self.set(8, 8 - skip - k);
+ self.set(self.width - 8 + k, 8);
+ }
+ }
+ }
+
+ fn is_maskinfo(&self, x: u8, y: u8) -> bool {
+ let end = self.width - 8;
+ // Count the dark module as mask info.
+ (x <= 8 && y == 8) || (y <= 8 && x == 8) || (x == 8 && y >= end) || (x >= end && y == 8)
+ }
+
+ // Version info: 18bits written twice, close to the finders.
+ fn draw_version_info(&mut self) {
+ let vinfo = self.version.version_info();
+ let pos = self.width - 11;
+
+ if vinfo != 0 {
+ for x in 0..3 {
+ for y in 0..6 {
+ if vinfo & (1 << (x + y * 3)) == 0 {
+ self.set(x + pos, y);
+ self.set(y, x + pos);
+ }
+ }
+ }
+ }
+ }
+
+ fn is_version_info(&self, x: u8, y: u8) -> bool {
+ let vinfo = self.version.version_info();
+ let pos = self.width - 11;
+
+ vinfo != 0 && ((x >= pos && x < pos + 3 && y < 6) || (y >= pos && y < pos + 3 && x < 6))
+ }
+
+ // Returns true if the module is reserved (Not usable for data and EC).
+ fn is_reserved(&self, x: u8, y: u8) -> bool {
+ self.is_alignment(x, y)
+ || self.is_finder(x, y)
+ || self.is_timing(x, y)
+ || self.is_maskinfo(x, y)
+ || self.is_version_info(x, y)
+ }
+
+ // Last module to draw, at bottom left corner.
+ fn is_last(&self, x: u8, y: u8) -> bool {
+ x == 0 && y == self.width - 1
+ }
+
+ // Move to the next module according to QR code order.
+ // From bottom right corner, to bottom left corner.
+ fn next(&self, x: u8, y: u8) -> (u8, u8) {
+ let x_adj = if x <= 6 { x + 1 } else { x };
+ let column_type = (self.width - x_adj) % 4;
+
+ match column_type {
+ 2 if y > 0 => (x + 1, y - 1),
+ 0 if y < self.width - 1 => (x + 1, y + 1),
+ 0 | 2 if x == 7 => (x - 2, y),
+ _ => (x - 1, y),
+ }
+ }
+
+ // Find next module that can hold data.
+ fn next_available(&self, x: u8, y: u8) -> (u8, u8) {
+ let (mut x, mut y) = self.next(x, y);
+ while self.is_reserved(x, y) && !self.is_last(x, y) {
+ (x, y) = self.next(x, y);
+ }
+ (x, y)
+ }
+
+ fn draw_data(&mut self, data: impl Iterator<Item = u8>) {
+ let (mut x, mut y) = (self.width - 1, self.width - 1);
+ for byte in data {
+ for s in 0..8 {
+ if byte & (0x80 >> s) == 0 {
+ self.set(x, y);
+ }
+ (x, y) = self.next_available(x, y);
+ }
+ }
+ // Set the remaining modules (0, 3 or 7 depending on version).
+ // because 0 correspond to a light module.
+ while !self.is_last(x, y) {
+ if !self.is_reserved(x, y) {
+ self.set(x, y);
+ }
+ (x, y) = self.next(x, y);
+ }
+ }
+
+ // Apply checkerboard mask to all non-reserved modules.
+ fn apply_mask(&mut self) {
+ for x in 0..self.width {
+ for y in 0..self.width {
+ if (x ^ y) % 2 == 0 && !self.is_reserved(x, y) {
+ self.xor(x, y);
+ }
+ }
+ }
+ }
+
+ // Draw the QR code with the provided data iterator.
+ fn draw_all(&mut self, data: impl Iterator<Item = u8>) {
+ // First clear the table, as it may have already some data.
+ self.clear();
+ self.draw_finders();
+ self.draw_alignments();
+ self.draw_timing_patterns();
+ self.draw_version_info();
+ self.draw_data(data);
+ self.draw_maskinfo();
+ self.apply_mask();
+ }
+}
+
+/// C entry point for the rust QR Code generator.
+///
+/// Write the QR code image in the data buffer, and return the QR code width,
+/// or 0, if the data doesn't fit in a QR code.
+///
+/// * `url`: The base URL of the QR code. It will be encoded as Binary segment.
+/// * `data`: A pointer to the binary data, to be encoded. if URL is NULL, it
+/// will be encoded as binary segment, otherwise it will be encoded
+/// efficiently as a numeric segment, and appended to the URL.
+/// * `data_len`: Length of the data, that needs to be encoded, must be less
+/// than data_size.
+/// * `data_size`: Size of data buffer, it should be at least 4071 bytes to hold
+/// a V40 QR code. It will then be overwritten with the QR code image.
+/// * `tmp`: A temporary buffer that the QR code encoder will use, to write the
+/// segments and ECC.
+/// * `tmp_size`: Size of the temporary buffer, it must be at least 3706 bytes
+/// long for V40.
+///
+/// # Safety
+///
+/// * `url` must be null or point at a nul-terminated string.
+/// * `data` must be valid for reading and writing for `data_size` bytes.
+/// * `tmp` must be valid for reading and writing for `tmp_size` bytes.
+///
+/// They must remain valid for the duration of the function call.
+
+#[no_mangle]
+pub unsafe extern "C" fn drm_panic_qr_generate(
+ url: *const i8,
+ data: *mut u8,
+ data_len: usize,
+ data_size: usize,
+ tmp: *mut u8,
+ tmp_size: usize,
+) -> u8 {
+ if data_size < 4071 || tmp_size < 3706 || data_len > data_size {
+ return 0;
+ }
+ // SAFETY: The caller ensures that `data` is a valid pointer for reading and
+ // writing `data_size` bytes.
+ let data_slice: &mut [u8] = unsafe { core::slice::from_raw_parts_mut(data, data_size) };
+ // SAFETY: The caller ensures that `tmp` is a valid pointer for reading and
+ // writing `tmp_size` bytes.
+ let tmp_slice: &mut [u8] = unsafe { core::slice::from_raw_parts_mut(tmp, tmp_size) };
+ if url.is_null() {
+ match EncodedMsg::new(&[&Segment::Binary(&data_slice[0..data_len])], tmp_slice) {
+ None => 0,
+ Some(em) => {
+ let qr_image = QrImage::new(&em, data_slice);
+ qr_image.width
+ }
+ }
+ } else {
+ // SAFETY: The caller ensures that `url` is a valid pointer to a
+ // nul-terminated string.
+ let url_cstr: &CStr = unsafe { CStr::from_char_ptr(url) };
+ let segments = &[
+ &Segment::Binary(url_cstr.as_bytes()),
+ &Segment::Numeric(&data_slice[0..data_len]),
+ ];
+ match EncodedMsg::new(segments, tmp_slice) {
+ None => 0,
+ Some(em) => {
+ let qr_image = QrImage::new(&em, data_slice);
+ qr_image.width
+ }
+ }
+ }
+}
+
+/// Returns the maximum data size that can fit in a QR code of this version.
+/// * `version`: QR code version, between 1-40.
+/// * `url_len`: Length of the URL.
+///
+/// * If `url_len` > 0, remove the 2 segments header/length and also count the
+/// conversion to numeric segments.
+/// * If `url_len` = 0, only removes 3 bytes for 1 binary segment.
+#[no_mangle]
+pub extern "C" fn drm_panic_qr_max_data_size(version: u8, url_len: usize) -> usize {
+ if version < 1 || version > 40 {
+ return 0;
+ }
+ let max_data = Version(version as usize).max_data();
+
+ if url_len > 0 {
+ // Binary segment (URL) 4 + 16 bits, numeric segment (kmsg) 4 + 12 bits => 5 bytes.
+ if url_len + 5 >= max_data {
+ 0
+ } else {
+ let max = max_data - url_len - 5;
+ (max * 39) / 40
+ }
+ } else {
+ // Remove 3 bytes for the binary segment (header 4 bits, length 16 bits, stop 4bits).
+ max_data - 3
+ }
+}
diff --git a/include/drm/drm_panic.h b/include/drm/drm_panic.h
index 73bb3f3d9ed9..7631548e7bbb 100644
--- a/include/drm/drm_panic.h
+++ b/include/drm/drm_panic.h
@@ -150,11 +150,15 @@ struct drm_scanout_buffer {
void drm_panic_register(struct drm_device *dev);
void drm_panic_unregister(struct drm_device *dev);
+void drm_panic_init(void);
+void drm_panic_exit(void);
#else
static inline void drm_panic_register(struct drm_device *dev) {}
static inline void drm_panic_unregister(struct drm_device *dev) {}
+static inline void drm_panic_init(void) {}
+static inline void drm_panic_exit(void) {}
#endif
