FreeCalypso > hg > freecalypso-tools
view target-utils/libload/intelflash.c @ 465:003e48f8ebe1
rvinterf/etmsync/fsnew.c: cast 0 to (char *) for execl sentinel
I generally don't use NULL and use plain 0 instead, based on a "NULL
considered harmful" discussion on the classiccmp mailing list many aeons
ago (I couldn't find it, and I reason that it must have been 2005 or
earlier), but a recent complaint by a packager sent me searching, and I
found this:
https://ewontfix.com/11/
While I don't give a @#$% about "modern" systems and code-nazi tools,
I realized that passing a plain 0 as a pointer sentinel in execl is wrong
because it will break on systems where pointers are longer than the plain
int type. Again, I don't give a @#$% about the abomination of x86_64 and
the like, but if anyone ever manages to port my code to something like a
PDP-11 (16-bit int, 32-bit long and pointers), then passing a plain 0
as a function argument where a pointer is expected most definitely won't
work: if the most natural stack slot and SP alignment unit is 16 bits,
fitting an int, with longs and pointers taking up two such slots, then
the call stack will be totally wrong with a plain 0 passed for a pointer.
Casting the 0 to (char *) ought to be the most kosher solution for the
most retro systems possible.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Mon, 11 Feb 2019 00:00:19 +0000 |
parents | e7502631a0f9 |
children |
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/* * This module implements the INFB and INFW commands for programming * Intel-style flash memories. The syntax and operation are exactly * the same as the AMD flash counterparts AMFB and AMFW. * * The intel-rewrite-sector command (erase+program with a minimum of * vulnerability for brickable-boot Compal phones) is implemented * here as well. */ #include <sys/types.h> #include "types.h" static u32 base_addr; void cmd_INFB(argbulk) char *argbulk; { char *argv[2]; u_long addr; if (parse_args(argbulk, 1, 1, argv, 0) < 0) return; if (parse_hexarg(argv[0], 8, &addr) < 0) { printf("ERROR: argument must be a valid 32-bit hex address\n"); return; } if (addr & 1) { printf("ERROR: odd address\n"); return; } base_addr = addr; } void cmd_INFW(argbulk) char *argbulk; { char *argv[3], *s; u_long offset; volatile u16 *flashptr; u32 datum; /* needs to be u32 for decode_hex_digits() */ u16 stat; int i; if (parse_args(argbulk, 2, 2, argv, 0) < 0) return; if (parse_hexarg(argv[0], 8, &offset) < 0) { printf("ERROR: offset argument must a valid 32-bit hex value\n"); return; } if (offset & 1) { printf("ERROR: odd offset argument\n"); return; } flashptr = (volatile u16 *)(base_addr + offset); for (s = argv[1]; *s; flashptr++, s += 4) { if (decode_hex_digits(s, 4, &datum) < 0) { printf("ERROR: bad INFW hex string argument\n"); return; } *flashptr = 0x40; *flashptr = datum; for (i = 10000; i; i--) { stat = *flashptr; if (stat & 0x80) break; } if (!i) { printf("ERROR: flash write timeout at %08X\n", (u_long) flashptr); return; } if (stat & 0x10) { printf("ERROR: program operation failed at %08X\n", (u_long) flashptr); return; } } } void cmd_intel_rewrite_sector(argbulk) char *argbulk; { char *argv[4]; u_long srcaddr, dstaddr, len; const u16 *srcptr; volatile u16 *flashptr; u16 stat; if (parse_args(argbulk, 3, 3, argv, 0) < 0) return; if (parse_hexarg(argv[0], 8, &srcaddr) < 0) { invarg: printf("ERROR: invalid argument(s)\n"); return; } if (parse_hexarg(argv[1], 8, &dstaddr) < 0) goto invarg; if (parse_hexarg(argv[2], 8, &len) < 0) goto invarg; if (srcaddr & 1 || dstaddr & 1 || len & 1) { printf("ERROR: all 3 arguments must be even\n"); return; } srcptr = (const u16 *) srcaddr; flashptr = (volatile u16 *) dstaddr; /* unlock the flash sector first */ *flashptr = 0x60; *flashptr = 0xD0; /* clear SR */ *flashptr = 0x50; /* erase */ *flashptr = 0x20; *flashptr = 0xD0; /* wait for erase completion */ for (;;) { stat = *flashptr; if (stat & 0x80) break; } if (stat & 0x30) { printf("ERROR: erase operation failed!\n"); return; } /* now program the new content */ for (; len; len -= 2) { *flashptr = 0x40; *flashptr = *srcptr++; for (;;) { stat = *flashptr; if (stat & 0x80) break; } flashptr++; } printf("Operation complete, final SR: %02X\n", stat & 0xFF); }