Remove lib/rocm_smi_lib and add instructions for obtaining it to README

.gitignore

@@ -51,6 +51,9 @@ bin
 btop
 .*/
 
+# Optional libraries
+lib/rocm_smi_lib
+
 
 #do not ignore .github directory
 !.github

.gitmodules

@@ -1,6 +1,3 @@
 [submodule "lib/fmt"]
 	path = lib/fmt
 	url = https://github.com/fmtlib/fmt
-[submodule "lib/rocm_smi_lib"]
-	path = lib/rocm_smi_lib
-	url = https://github.com/RadeonOpenCompute/rocm_smi_lib

README.md

@@ -341,6 +341,13 @@ Also needs a UTF8 locale and a font that covers:
    Append `ARCH=<architecture>` to manually set the target architecture.
    If omitted the makefile uses the machine triple (output of `-dumpmachine` compiler parameter) to detect the target system.
 
+   Append `RSMI_STATIC=true` to statically link the ROCm SMI library used for querying AMDGPU data.
+   For this to work, the `lib/rocm_smi_lib` directory must contain the RSMI source code, which can obtained using the following command:
+
+   ```bash
+   git clone https://github.com/RadeonOpenCompute/rocm_smi_lib.git lib/rocm_smi_lib
+   ```
+
    Use `ADDFLAGS` variable for appending flags to both compiler and linker.
 
    For example: `ADDFLAGS=-march=native` might give a performance boost if compiling only for your own system.

lib/rocm_smi_lib

@@ -1 +0,0 @@
-Subproject commit f8882d74d8749e2ad788184d624167cc326d4c2c

src/linux/btop_collect.cpp

@@ -29,7 +29,6 @@ tab-size = 4
 #include <net/if.h>
 #include <arpa/inet.h> // for inet_ntop()
 #include <dlfcn.h>
-#include <rocm_smi/rocm_smi.h>
 
 
 #if !(defined(STATIC_BUILD) && defined(__GLIBC__))
@@ -155,6 +154,23 @@ namespace Gpu {
 	//? AMD data collection
 	namespace Rsmi {
 	#if !defined(RSMI_STATIC)
+		//? RSMI defines, structs & typedefs
+		#define RSMI_MAX_NUM_FREQUENCIES  32
+		#define RSMI_STATUS_SUCCESS        0
+		#define RSMI_MEM_TYPE_VRAM         0
+		#define RSMI_TEMP_CURRENT          0
+		#define RSMI_TEMP_TYPE_EDGE        0
+		#define RSMI_CLK_TYPE_MEM          4
+		#define RSMI_CLK_TYPE_SYS          0
+		#define RSMI_TEMP_MAX              1
+
+		typedef int rsmi_status_t,
+					rsmi_temperature_metric_t,
+					rsmi_clk_type_t,
+					rsmi_memory_type_t;
+
+		struct rsmi_frequencies_t {uint32_t num_supported, current, frequency[RSMI_MAX_NUM_FREQUENCIES];};
+
 		//? Function pointers
 		rsmi_status_t (*rsmi_init)(uint64_t);
 		rsmi_status_t (*rsmi_shut_down)();