From d4e53ae638b22b053ecccfddab535f639ba9f790 Mon Sep 17 00:00:00 2001
From: Evan Reichard <evan@reichard.io>
Date: Mon, 20 Jul 2026 09:03:16 -0400
Subject: [PATCH] fix(m25p80): answer Read-ID 0x90/0xAB for all chips, not just
 SST

CrossPoint flash detection sends Read-ID (0x90/0xAB); the model only handled it
for SST chips, so the is25lp128 returned nothing and detection fell into an
SFDP/garbage path that crashed QEMU. Return manufacturer + device id for any
chip, as real hardware does.
---
 qemu/patches/0002-qemu-wasm.patch | 43 +++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/qemu/patches/0002-qemu-wasm.patch b/qemu/patches/0002-qemu-wasm.patch
index 0a3812b..4e4f6ee 100644
--- a/qemu/patches/0002-qemu-wasm.patch
+++ b/qemu/patches/0002-qemu-wasm.patch
@@ -324,6 +324,49 @@ index 89087429c7..4d38b3e13c 100644
                     : ADC_MAX;
      }
      return s->regs[addr / 4];
+diff --git a/hw/block/m25p80.c b/hw/block/m25p80.c
+index 46dbe7c521..4f05caf34e 100644
+--- a/hw/block/m25p80.c
++++ b/hw/block/m25p80.c
+@@ -856,28 +856,18 @@ static void complete_collecting_data(Flash *s)
+         break;
+     case RDID_90:
+     case RDID_AB:
+-        if (get_man(s) == MAN_SST) {
+-            if (s->cur_addr <= 1) {
+-                if (s->cur_addr) {
+-                    s->data[0] = s->pi->id[2];
+-                    s->data[1] = s->pi->id[0];
+-                } else {
+-                    s->data[0] = s->pi->id[0];
+-                    s->data[1] = s->pi->id[2];
+-                }
+-                s->pos = 0;
+-                s->len = 2;
+-                s->data_read_loop = true;
+-                s->state = STATE_READING_DATA;
+-            } else {
+-                qemu_log_mask(LOG_GUEST_ERROR,
+-                              "M25P80: Invalid read id address\n");
+-            }
++        // Read Manufacturer/Device ID - The address low bit selects which of the manufacturer/device pair comes first; real chips answer regardless of vendor, so this is not gated on MAN_SST. Reused for 0xAB (Release Power-Down + Device ID), whose trailing byte reads back the device id.
++        if (s->cur_addr) {
++            s->data[0] = s->pi->id[2];
++            s->data[1] = s->pi->id[0];
+         } else {
+-            qemu_log_mask(LOG_GUEST_ERROR,
+-                          "M25P80: Read id (command 0x90/0xAB) is not supported"
+-                          " by device\n");
++            s->data[0] = s->pi->id[0];
++            s->data[1] = s->pi->id[2];
+         }
++        s->pos = 0;
++        s->len = 2;
++        s->data_read_loop = true;
++        s->state = STATE_READING_DATA;
+         break;
+ 
+     case RDSFDP:
 diff --git a/hw/display/xteink_x3_eink.c b/hw/display/xteink_x3_eink.c
 index b699abae4e..8a177e9159 100644
 --- a/hw/display/xteink_x3_eink.c