id = 1555
title = "virt platform mrom"
state = "closed"
created_at = "2023-03-24T03:47:07.313Z"
closed_at = "2023-05-17T05:00:04.128Z"
labels = ["accel: TCG", "target: riscv"]
url = "https://gitlab.com/qemu-project/qemu/-/issues/1555"
host-os = "ubuntu22.04"
host-arch = "x86"
qemu-version = "7.2.0"
guest-os = "n/a"
guest-arch = "n/a"
description = """qemu-system-riscv32 to emulated the lowrisc ibex simple system hello, when debug with riscv32-unknown-elf-gdb, there kept logging "Invalid read at addr 0x0, size 2, region '(null)', reason: rejected".  
I saw qemu virt platform codes related to this error, it load reset_vec to 0x1000 called VIRT_MROM. I still not understand why this error happens."""
reproduce = """1.git clone https://github.com/lowRISC/ibex.git  
2.cd ibex  
3.make -C examples/sw/simple_system/hello_test  
4.using the qemu command line above  
5.`riscv32-unknown-elf-gdb -ex target remote localhost:1234 examples/sw/simple_system/hello_test` in another terminal, type bt, the error happens."""
additional = """```gdb
(gdb) x/16i $pc 
=> 0x1000:\tauipc\tt0,0x0
   0x1004:\taddi\ta2,t0,40
   0x1008:\tcsrr\ta0,mhartid
   0x100c:\tlw\ta1,32(t0)
   0x1010:\tlw\tt0,24(t0)
   0x1014:\tjr\tt0
   0x1018:\tunimp
   0x101a:\t.2byte\t0x8000
   0x101c:\tunimp
   0x101e:\tunimp
   0x1020:\tunimp
   0x1022:\t.2byte\t0x7fe0
   0x1024:\tunimp
   0x1026:\tunimp
   0x1028:\t.4byte\t0x4942534f
   0x102c:\tc.slli64\tzero
(gdb) bt
#0  0x00001000 in ?? ()
```"""