These are just jumps to the address. In that specific example there is 0 in r4 (the first parameter).
Most addresses on the calculator do not have syscalls associated with them, so you can't call them like that. Instead, if you want to call that address, i suggest using a function similar to this, which looks through the instructions in a syscall which references that address and then jumps to it:
Code:
static void SaveAndOpenMainMenu(void) {
int addr;
// get the pointer to the syscall table
addr = *(unsigned int *)0x8002007C;
// now addr has the address of the syscall table in it
if (addr < (int)0x80020070)
return;
if (addr >= (int)0x81000000)
return;
// get the pointer to syscall 1E58 - SwitchToMainMenu
addr += 0x1E58 * 4;
if (addr < (int)0x80020070)
return;
if (addr >= (int)0x81000000)
return;
addr = *(unsigned int *)addr;
if (addr < (int)0x80020070)
return;
if (addr >= (int)0x81000000)
return;
// Now addr has the address of the first operation in %1e58
// Run up to 150 times (300/2). OS 3.60's is 59 instructions, so this should
// be plenty, but will let it stop if nothing is found
for (unsigned short *currentAddr = (unsigned short *)addr;
(unsigned int)currentAddr < ((unsigned int)addr + 300); currentAddr++) {
// MOV.L GetkeyToMainFunctionReturnFlag, r14
if (*(unsigned char *)currentAddr != 0xDE)
continue;
// MOV #3, 2
if (*(currentAddr + 1) != 0xE203)
continue;
// BSR <SaveAndOpenMainMenu>
if (*(unsigned char *)(currentAddr + 2) != 0xB5)
continue;
// MOV.B r2, @r14
if (*(currentAddr + 3) != 0x2E20)
continue;
// BRA <some addr>
if (*(currentAddr + 4) != 0xAFFB)
continue;
// NOP
if (*(currentAddr + 5) != 0x0009)
continue;
unsigned short branchInstruction = *(currentAddr + 2);
// Clear first 4 bits (BSR identifier)
branchInstruction <<= 4;
branchInstruction >>= 4;
// branchInstruction is now the displacement of BSR
// Create typedef so we can cast the pointer
typedef void (*voidFunc)(void);
// JMP to disp*2 + PC + 4
((voidFunc)((unsigned int)branchInstruction * 2 +
(unsigned int)currentAddr + 4 + 4))();
return;
}
}