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Strip header from loaded module

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This commit is contained in:
David Schmenk 2014-05-16 20:37:36 -07:00
parent eb746fb5a0
commit 2c9986fd25
1 changed files with 52 additions and 34 deletions
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66
PLASMA/src/plvm.c
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@ -228,7 +228,8 @@ uword extern_lookup(byte *esd, int index)
}
int load_mod(byte *mod)
{
uword len, size, end, magic, bytecode, fixup, addr, sysflags, defcnt = 0, init = 0, modaddr = mark_heap();
uword modsize, hdrlen, len, end, magic, bytecode, fixup, addr, sysflags, defcnt = 0, init = 0, modaddr = mark_heap();
word modfix;
byte *moddep, *rld, *esd, *cdd, *sym;
byte header[128];
int fd;
@ -239,7 +240,8 @@ int load_mod(byte *mod)
fd = open(filename, O_RDONLY, 0);
if ((fd > 0) && (len = read(fd, header, 128)) > 0)
{
modaddr = mark_heap();
moddep = header + 1;
modsize = header[0] | (header[1] << 8);
magic = header[2] | (header[3] << 8);
if (magic == 0xDA7E)
{
@ -251,35 +253,51 @@ int load_mod(byte *mod)
defcnt = header[8] | (header[9] << 8);
init = header[10] | (header[11] << 8);
moddep = header + 12;
if (*moddep)
{
/*
* Load module dependencies.
*/
close(fd);
while (*moddep)
{
if (lookup_mod(moddep) == 0)
{
if (fd)
{
close(fd);
fd = 0;
}
load_mod(moddep);
}
moddep += dcitos(moddep, string);
}
modaddr = mark_heap();
if (fd == 0)
{
fd = open(filename, O_RDONLY, 0);
len = read(fd, mem_data + modaddr, 128);
len = read(fd, header, 128);
}
else
memcpy(mem_data + modaddr, header, len);
}
addr = modaddr + len;
while ((len = read(fd, mem_data + addr, 4096)) > 0)
addr += len;
close(fd);
size = addr - modaddr;
len = mem_data[modaddr + 0] | (mem_data[modaddr + 1] << 8);
/*
* Alloc heap space for relocated module (data + bytecode).
*/
moddep += 1;
hdrlen = moddep - header;
len -= hdrlen;
modaddr = mark_heap();
end = modaddr + len;
rld = mem_data + modaddr + len; // Re-Locatable Directory
/*
* Read in remainder of module into memory for fixups.
*/
memcpy(mem_data + modaddr, moddep, len);
while ((len = read(fd, mem_data + end, 4096)) > 0)
end += len;
close(fd);
/*
* Apply all fixups and symbol import/export.
*/
modfix = modaddr - hdrlen - MOD_ADDR;
bytecode += modfix;
end = modaddr - hdrlen + modsize;
rld = mem_data + end; // Re-Locatable Directory
esd = rld; // Extern+Entry Symbol Directory
bytecode += modaddr - MOD_ADDR;
while (*esd != 0x00) // Scan to end of RLD
esd += 4;
esd++;
@ -289,8 +307,8 @@ int load_mod(byte *mod)
/*
* Dump different parts of module.
*/
printf("Module size: %d\n", size);
printf("Module code+data size: %d\n", len);
printf("Module size: %d\n", end - modaddr + hdrlen);
printf("Module code+data size: %d\n", modsize);
printf("Module magic: $%04X\n", magic);
printf("Module sysflags: $%04X\n", sysflags);
printf("Module bytecode: $%04X\n", bytecode);
@ -308,7 +326,7 @@ int load_mod(byte *mod)
{
if (show_state) printf("\tDEF CODE");
addr = rld[1] | (rld[2] << 8);
addr += modaddr - MOD_ADDR;
addr += modfix;
rld[1] = addr;
rld[2] = addr >> 8;
end = rld - mem_data + 4;
@ -316,7 +334,7 @@ int load_mod(byte *mod)
else
{
addr = rld[1] | (rld[2] << 8);
addr += modaddr - MOD_ADDR;
addr += modfix;
if (rld[0] & 0x80)
fixup = mem_data[addr] | (mem_data[addr + 1] << 8);
else
@ -329,7 +347,7 @@ int load_mod(byte *mod)
else
{
if (show_state) printf("\tINTERN ");
fixup += modaddr - MOD_ADDR;
fixup += modfix;
if (fixup >= bytecode)
/*
* Replace with call def dictionary.
@ -363,7 +381,7 @@ int load_mod(byte *mod)
else if (esd[0] & 0x08)
{
addr = esd[1] | (esd[2] << 8);
addr += modaddr - MOD_ADDR;
addr += modfix;
if (show_state) printf("\tEXPORT %s@$%04X\n", string, addr);
if (addr >= bytecode)
addr = def_lookup(cdd, addr);
@ -386,7 +404,7 @@ int load_mod(byte *mod)
*/
if (init)
{
interp(mem_data + init + modaddr - MOD_ADDR);
interp(mem_data + init + modfix);
return POP;
}
return 0;