[3/8] arc: libgloss: Clean MetaWare hostlink documentation
Commit Message
From: Yuriy Kolerov <ykolerov@synopsys.com>
Signed-off-by: Yuriy Kolerov <ykolerov@synopsys.com>
---
libgloss/arc/readme-hostlink.md | 134 ++++++++++++++++----------------
1 file changed, 67 insertions(+), 67 deletions(-)
@@ -1,90 +1,90 @@
-Metaware hostlink IO
+MetaWare Hostlink IO
====================
-This directory includes target-side implementation of Metaware hostlink
-interface see Contents section. Target program can use Metaware hostlink
-interface to send messages to nsim simulator or mdb debugger (it can be
-attached to HW or nsim).
+Target program can use MetaWare hostlink interface to send messages to nSIM
+simulator or MDB debugger.
-Quick start
+Quick Start
-----------
-To link with this version of libgloss please add `-specs=hl.specs` to baremetal
-version of ARC gcc (arc-elf32).
-Lets build and run simple program:
+To link with MetaWare hostlink library use `-specs=hl.specs` with baremetal
+version of GCC for ARC processors - `arc-elf32-gcc` for ARCv1/2 targets or
+`arc64-elf-gcc` for ARCv3 targets.
+
+Consider this sample program named `hello.c`:
- $ cat hello.c
#include <stdio.h>
int main()
{
- printf("Hello World!\n");
-
- return 0;
+ printf("Hello, World!\n");
+ return 0;
}
- $ arc-elf32-gcc -mcpu=hs -specs=hl.specs ./hello.c -o hello
- $ nsimdrv -prop=nsim_isa_family=av2hs -prop=nsim_hlink_gnu_io_ext=1 ./hello
- Hello World!
-Where `-mcpu` and `-prop=nsim_isa_family` is specific to your version of ARC CPU.
-Option `-prop=nsim_hlink_gnu_io_ext=1` enables GNU IO extension for nSIM which
-is used for some system calls. The `nsimdrv` option `-prop=nsim_emt={0,1,2}`
-enables trap emulation and should be disabled (removed or set to `0`) to use
-Metaware hostlink.
+Build and run it for HS3x/4x targets:
+
+ $ arc-elf32-gcc -mcpu=hs -specs=hl.specs hello.c -o hello.elf
+ $ nsimdrv -tcf $NSIM_HOME/etc/tcf/templates/hs48_full.tcf -p nsim_hostlink=1 hello.elf
+ Hello, World!
+
+Build and run it for HS5x targets:
+
+ $ arc64-elf-gcc -mcpu=hs5x -specs=hl.specs hello.c -o hello.elf
+ $ nsimdrv -tcf $NSIM_HOME/etc/tcf/templates/hs58_full.tcf -p nsim_hostlink=1 hello.elf
+ Hello, World!
-**NB:** Metaware hostlink requires symbols `__HOSTLINK__` and `_hl_blockedPeek`
-to be present. So stripped binary won't work properly with Metaware hostlink.
+Build and run it for HS6x targets:
+
+ $ arc64-elf-gcc -mcpu=hs6x -specs=hl.specs hello.c -o hello.elf
+ $ nsimdrv -tcf $NSIM_HOME/etc/tcf/templates/hs68_full.tcf -p nsim_hostlink=1 hello.elf
+ Hello, World!
Contents
--------
-* `hl/hl_gw.*` -- Hostlink gateway. This API is used in the `hl_api.*`.
- Please use `hl_message()` from `hl_api.*` for hostlink
- message exchange.
-* `hl/hl_api.*` -- High-level API to send hostlink messages, as well as
- functions to work with messages.
-* `hl/hl_<syscall>.*` -- Syscall implementations through hostlink API;
-* `arc-timer.*` -- Provides API to access ARC timers. Used by
- `hl/hl_clock.c` in `_clock()` implementation.
-* `arc-main-helper.c` -- Provides `__setup_argv_and_call_main()`. The function
- is called from `__start()` in `crt0.S`. It allows
- to setup `argc` and `arvg` as well as some custom
- things through `_setup_low_level()`.
-* `hl-setup.c` -- Provides `_setup_low_level()` for hostlink case.
- It just configures default timer if it exists. Default
- timer is used in the hostlink `clock()`
- implementation.
-* `hl-stub.c` -- Provides functions which are part of newlib but
- implemented without hostlink.
- e.g. `_kill()` and `_getpid()`.
-* `sbrk.c` -- Provides `_sbrk()`. It uses `__start_heap` and
- `__end_heap` variables.
-* `libcfunc.c` -- Additional C system calls.
-* `mcount.c` -- Profiler support.
-
-How it works
+
+* `hl/hl_gw.*` - Hostlink gateway. This API is used in the `hl_api.*`.
+ Please use `hl_message()` from `hl_api.*` for hostlink message exchange.
+* `hl/hl_api.*` - High-level API to send hostlink messages, as well as
+ functions to work with messages.
+* `hl/hl_<syscall>.*` - System calls implementations through hostlink API.
+* `arc-timer.*` - Provides API to access ARC timers. Used by `hl/hl_clock.c`
+ in `_clock()` implementation.
+* `arc-main-helper.c` - Provides `__setup_argv_and_call_main()`. The function
+ is called from `__start()` in `crt0.S`. It allows to setup `argc` and `arvg`
+ as well as some custom things through `_setup_low_level()`.
+* `hl-setup.c` - Provides `_setup_low_level()` for hostlink case. It just
+ configures default timer if it exists. Default timer is used in the hostlink
+ `clock()` implementation.
+* `hl-stub.c` - Provides functions which are part of newlib but implemented
+ without hostlink. For example, `_kill()` and `_getpid()`.
+* `sbrk.c` - Provides `_sbrk()`. It uses `__start_heap` and `__end_heap`
+ variables.
+* `libcfunc.c` - Additional C system calls.
+* `mcount.c` - Profiler support.
+
+How It Works
------------
+
Simulator looks for `__HOSTLINK__` and `_hl_blockedPeek()` symbols.
`__HOSTLINK__` is the start of shared structure for message exchange and
`_hl_blockedPeek()` is a function to be called when program is waiting
for simulator response.
When program wants to send a message it should follow:
- 1. Fill `__HOSTLINK__.payload` with packed data.
- Packing format is following: `{u16 type, u16 size, char data[]}`.
- Supported types are `char`, `short`, `int`, `string` and `int64`.
- `hl_api` provides high-level API to this.
- 2. Fill `__HOSTLINK__.pkt_hdr`. See `hl_pkt_init()` from `hl_gw.c`.
- 3. Fill `__HOSTLINK__.hdr`. See `hl_send()` from `hl_gw.c`.
- 4. Call `_hl_blockedPeek()` to get response.
- At this point message should be delivered to debugger.
- Some implementations uses change of `__HOSTLINK__.hdr.target2host_addr` as
- a signal that packet is sent and can be processed. Other implementations
- wait for `_hl_blockedPeek()` to be called.
-
- It means that portable implementation must fill
- `__HOSTLINK__.hdr.target2host_addr` at the last step and then call
- `_hl_blockedPeek()`.
- 5. `_hl_blockedPeek()` returns pointer to debugger response which can be
- processed on target if needed. Because debugger and target share the same
- buffer the function actually returns `__HOSTLINK__.payload` that was
- filled with packed data (see step 1) by the debugger.
+
+1. Fill `__HOSTLINK__.payload` with packed data. Packing format is following:
+ `{u16 type, u16 size, char data[]}`. Supported types are `char`, `short`,
+ `int`, `string` and `int64`. `hl_api` provides high-level API to this.
+2. Fill `__HOSTLINK__.pkt_hdr`. See `hl_pkt_init()` from `hl_gw.c`.
+3. Fill `__HOSTLINK__.hdr`. See `hl_send()` from `hl_gw.c`.
+4. Call `_hl_blockedPeek()` to get response. At this point message should be
+ delivered to debugger. Some implementations uses change of
+ `__HOSTLINK__.hdr.target2host_addr` as a signal that packet is sent and can
+ be processed. Other implementations wait for `_hl_blockedPeek()` to be
+ called. It means that portable implementation must fill
+ `__HOSTLINK__.hdr.target2host_addr` at the last step and then call
+ `_hl_blockedPeek()`.
+5. `_hl_blockedPeek()` returns pointer to debugger response which can be
+ processed on target if needed. Because debugger and target share the same
+ buffer the function actually returns `__HOSTLINK__.payload` that was
+ filled with packed data (see step 1) by the debugger.