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Diffstat (limited to 'qemu/target-lm32/README')
| -rw-r--r-- | qemu/target-lm32/README | 45 |
1 files changed, 0 insertions, 45 deletions
diff --git a/qemu/target-lm32/README b/qemu/target-lm32/README deleted file mode 100644 index ba3508a71..000000000 --- a/qemu/target-lm32/README +++ /dev/null @@ -1,45 +0,0 @@ -LatticeMico32 target --------------------- - -General -------- -All opcodes including the JUART CSRs are supported. - - -JTAG UART ---------- -JTAG UART is routed to a serial console device. For the current boards it -is the second one. Ie to enable it in the qemu virtual console window use -the following command line parameters: - -serial vc -serial vc -This will make serial0 (the lm32_uart) and serial1 (the JTAG UART) -available as virtual consoles. - - -Semihosting ------------ -Semihosting on this target is supported. Some system calls like read, write -and exit are executed on the host if semihosting is enabled. See -target/lm32-semi.c for all supported system calls. Emulation aware programs -can use this mechanism to shut down the virtual machine and print to the -host console. See the tcg tests for an example. - - -Special instructions --------------------- -The translation recognizes one special instruction to halt the cpu: - and r0, r0, r0 -On real hardware this instruction is a nop. It is not used by GCC and -should (hopefully) not be used within hand-crafted assembly. -Insert this instruction in your idle loop to reduce the cpu load on the -host. - - -Ignoring the MSB of the address bus ------------------------------------ -Some SoC ignores the MSB on the address bus. Thus creating a shadow memory -area. As a general rule, 0x00000000-0x7fffffff is cached, whereas -0x80000000-0xffffffff is not cached and used to access IO devices. This -behaviour can be enabled with: - cpu_lm32_set_phys_msb_ignore(env, 1); - |